FOUS30 KWBC 271550
QPFERD

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
1150 AM EDT Wed May 27 2026

Day 1
Valid 16Z Wed May 27 2026 - 12Z Thu May 28 2026

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL ACROSS PORTIONS OF
SOUTHEAST TEXAS, CENTRAL GULF COAST, AND AREAS OF THE OHIO VALLEY
TO CENTRAL APPALACHIANS...

16Z update... A modest eastward adjustment of the Marginal Risk was
made across eastern Maryland and into the Virginia Outer banks and
western Delaware for ongoing convection. Refer to MPD #258 for=20
further details for the near-term heavy rain/flash flooding threat.
Multiple cells are expected to focus/repeat over portions of=20
northern West Virginia with rainfall rates upwards of 1.5-2 in/hr=20
this afternoon and evening which would place this part of the=20
region in the higher end of the flash flooding threat within the=20
Slight Risk area.=20

Campbell

12Z Special...
Minor adjustment was made to the southern extent of the Marginal
Risk across South Texas to reflect ongoing convection. Refer to MPD
#256 for further details regarding the near-term heavy rain/flash
flooding threat across this region.

Pereira

...Texas to Central Gulf Coast...

Radar this evening is pretty telling with the current evolution
over TX revealing quite the complex of thunderstorms migrating
eastward out Hill Country into the I-35 corridor. These storms will
continue to shove eastward with assistance from both a relatively
solid mean steering flow and outflow propagation stemming from the
organized convection. Aloft, two notable features are depicted via
WV satellite and UA analysis across the Southern Plains. The first
is a well-defined negatively tilted trough oriented over NM into
the TX Panhandle that will be slow to deviate from its current
positioning over the course of the D1, even some prospects of the
upper pattern closing off across the Panhandle area of TX/OK which
would allow for some general enhancement of organized convective
clusters under the primary circulation stemming from any upper
low (ULL). In any case, this general upper pattern across the
region will entice broad cyclonic flow across the south-central
portion of the CONUS leading to convective development around the
periphery of the trough/ULL with an extension of activity likely to
be situated from southeastern CO, across KS and OK, and eventually
swinging back into the Lower Mississippi Valley. Instability maxima
will still be located further to the south and east within closer
proxy to the Gulf, however the upper levels and generally above
normal PWAT anomalies over the entire scope of the Southern Plains
should still act as a favorable environment for locally heavy
rainfall leading to some flash flood prospects over the arcing area
referenced above.

That said, one of the wild cards at play in this setup is the maturation/development of any MCV structures that would locally
enhance convective episodes and likely trigger a more beneficial
low-level convergence pattern capable of better flash flood
prospects. This has been an output via some of the CAMs this
evening, most notably the HRRR where MCV development across OK
would trigger some locally enhanced precip maxima located within
the broad cyclonic presence. These features are tough to forecast
in the short term with more of a nowcasting component likely to be
instituted before committing to anything more concrete in the
forecast, so this will bear watching over the course of the D1.

The more notable feature of interest for this evening and carrying
through the D1 will likely be the evolution of a trailing vorticity
maxima ejecting out of Coahuila this evening with the current
radar/sat composite indicating a cluster of thunderstorms currently
migrating east out of the Mexican state. The current MCS over Texas
has a defined southern edge arcing back into south TX with a strong
cell currently situated above 50 miles to the east of Laredo.
Recent 00z CAMs indicate the Mexican disturbance following the tail
end of the complex over TX and focusing on a heavy rain core
trailing across south TX with a due east push of the mid-level
disturbance. Consensus on heavy rainfall for the period will begin
across southeast TX with the highlight likely to start around
Corpus Christi and surrounds with moderate to heavy rain lingering
across the Upper TX coast. As the outflow from the current complex
shoves east, the environment will become stabilized behind the
complex leading to a weakening convective regime as the disturbance
to the south begins to enter into the region. There's some
discrepancy on the specifics of the convective placement as we step
through the morning, but the trends are for the immediate TX Gulf
coast into southern LA as being the most notable areas of interest
with the evolution of expected heavy rainfall during the D1. This
is reflected well within the neighborhood prob fields off the
latest HREF signaling >3" running between 40-70% across the entire
stretch from Port O'Connor all the way towards New Orleans.
Downstream prospects are more in due part to the continued
southerly flow continuing to advect deep moisture into the region
allowing for an environment capable of producing heavy convection
during peak afternoon heating. The migration of the outflow on the
northern edge of the current complex will likely skirt the southern
portion of LA with some models maintaining its presence as far east
as southeastern LA before it finally dwindles. In any case, the
environmental favorability in the period lies within that coastal
plain where elevated theta_E's lend to a heightened threat for
heavy rainfall in anything that crops up with hourly rates likely
to reach 2-3"/hr in the heavier cell cores.

Considering the complex evolutions referenced above for both areas
of interest, the highest probabilities aligning with the Upper TX
and Central Gulf coast allows for a continued SLGT risk positioning
in these locations with a broad MRGL encompassing the overall
cyclonic pattern oriented over the Southern Plains to Lower
Mississippi Valley. Will still need to monitor the evolution
closely as deviations in the outflow positioning, or the
introduction of either closed ULL reflections or MVC's over the
Southern Plains could very well aid in additional upgrades in any
areas encompassed by these features.

...Ohio Valley to Central Appalachians...

Latest surface analysis over the Ohio Valley to Mid Atlantic
indicates a defined quasi-stationary front bisecting northern KY
through southern WV into central VA with pockets of showers
currently migrating northeast within the mean flow around a broad
ridge extension off the Atlantic seaboard. This frontal alignment
and lingering mid-level vorticity analyzed over the Ohio Valley
will lead to scattered to widespread convective regime over the
course of today with a heightened threat for locally heavy rainfall
occurring by late-morning and afternoon as environmental
destabilization takes shape. The frontal placement will be
important with regards to eventual convective initiation as this
will become a focal point for any future development over the
course of the afternoon. Model consensus is the boundary wavering
slowly to the north during the morning as a weak disturbance begins
to ride along the boundary leading to some minor regional
amplification and a slow push north of the front to about the
latitude of I-70. A sweeping trough exiting out of Ontario will
also help tighten an axis of confluence across the Midwest and
Ohio Valley by later in the afternoon, enticing a squeeze of the
thermal gradient and regional instability axis that aligns with the
frontal placement.

Instability markers by the afternoon hours will run between
2000-3000 J/kg for MUCAPE with weak shear presence leading to
scattered to widespread thunderstorm initiation along and south of
the front with generally modest cell motions to the southeast after development. PWAT anomalies will sit firmly within +2 standard
deviations above climo within the proposed area of impact, a factor
that will correlate to strong cell cores capable of heavier
downpours with hourly rates between 1-2"/hr. Previous periods of
rainfall in the last three to four days have really brought down
the areal FFG markers for all 1/3/6 hour thresholds with a vast
majority of places along the Ohio River basin and points north
running <1"/hr in the hourly exceedance indicator. This points to
any heavier convective impacts could cause issues with the remnant
soil moisture and hydrologic concerns that are lingering after the
last event. This is especially true for eastern OH, southwest PA,
and western WV where complex topography only exacerbate the
potential in these zones. The latest 00z HREF continues to paint a
favorable concept of heavier rain prospects along and south of I-70
with a corridor of heavier rainfall likely to occur over southeast
IN through southern OH into northwest WV. EAS probs for >1" are
actually pretty elevated (50-80%) in the zone along I-79 over
towards the Appalachian front in WV with modest probs of 25-40%
located along the aforementioned line extending through IN/OH. A
lot of the flash flood focus will likely correlate with the hourly
rates and overlap of heavy rain over areas still saturated from
previous periods. Considering the antecedent conditions and
expected widespread convective regime along the front, the SLGT
risk was maintained for an increasing threat for flash flooding
during the period.

...Northern Rockies...

Relatively buoyant environment within a deep, anomalous moisture
presence across the Northern Rockies along with regional ascent
provided by sheared vorticity maxima maneuvering through the area
will allow for another round of widely scattered convection to
materialize across the Lewis Range in northwest MT. Instability and
regional forcing will be a bit less than the previous period,
however sensitivities remain from remnant burn scars present
within the mountainous terrain in the aforementioned area which is
a cause for concern for any cells that happen to occur over the
burn scars themselves. Hourly rates between 0.5-1"/hr in the
stronger cell cores would be capable of providing localized flash
flood impacts over those more sensitive grounds and this setup will
maintain the prospects given the anomalous moisture presence as
PWATs remain above the 90th percentile over the entire stretch of
the Northern Rockies. The previous MRGL risk inherited was
maintained given the relative continuity.

Kleebauer


Day 2
Valid 12Z Thu May 28 2026 - 12Z Fri May 29 2026

...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL ACROSS PORTIONS
OF THE CENTRAL AND SOUTHERN PLAINS, NORTHERN ROCKIES, LOWER
MISSISSIPPI VALLEY, AND SOUTHEAST FLORIDA...

...Plains to Lower Mississippi Valley...

A bit of an omega block pattern is shaping up across the CONUS with
a broad upper trough axis fixated over the Central and Southern
Plains with with ridging in place over the top. This will cause a
rather chaotic flow under the mean trough with deep moisture and
several smaller mid-level perturbations basically "stuck" under the
the overall trough axis. Ample instability with deep moisture
presence will certain be a cause for continuing at least a
scattered heavy rain footprint across areas under the influence of
the trough. Scattered elevated probabilities between 30-60% exists
for localized amounts >2" from KS all the way into the Southeast
U.S. with the maxima split between KS and the Central Gulf coast.
The two areas are different in the reasoning as the primary center
of the trough will be fixed over KS leading to the best upper
forcing pattern and stagnant flow remaining parked over the area as
we move through D2. Pending the amount of rain that falls over the
course of D1, a targeted upgrade is possible, but maintained the
MRGL and will reassess as we move forward in future updates to see
if an upgrade is warranted. The Central Gulf coast will remain in a
favorable instability maxima with weak flow likely a component that
could lead to isolated heavy totals stemming from slow-moving
convection. The area from the Upper TX coast over through southern
GA has been leaning wet over the past week, so antecedent
conditions are a little more unforgiving for these types of setups.
In any case, the threat remains modest, at best, so the MRGL risk
was sufficient for the pattern with any upgrades likely to stem
from more near term sampling of the radar trends.

...Florida...

Active sea breeze pattern with weakening steering flow will lead
to a period of heavy rainfall across the southeast FL coast on
Thursday afternoon. Consensus within guidance is for an active
period between 18-00z Thu/Fri that would allow for heavy convection
with slow forward propagations to impact the South Florida metro
corridor from West Palm Beach down to Miami. Latest 00z HREF is
modestly robust with the signature for at least 3" off the
neighborhood probabilities with a steady 60-90% output along the
southeastern coast of FL with the maxima generally confined to the
Miami Metro up to West Palm Beach. This correlates strongly with
what has been advertised via regional and global guidance the past
few days with the deterministic CAMs even indicating some 4-6"
bullseye's within the main QPF footprint. This is a relatively
classic pattern capable of locally significant rainfall within a
deep moisture presence as PWAT anomalies sit between +1 to +2
standard deviations within the various ensemble packages. A MRGL
risk remains in effect for the period across the South Florida
metro corridor.

...Northern Rockies...

Maturing ULL over the west coast will allow for a broad axis of
diffluent flow across the interior northwest with the highlight of
scattered convection likely to pivot further west into eastern WA,
northern ID, and the western slopes of the Northern Rockies.
Signals are not as prevalent compared to previous periods, however
the environmental conditions are still favorable, especially when
it comes to PWAT anomalies still generally running between the
90-95th percentile across northeast WA into northern ID. Burn scar
remnants will likely be the most susceptible to seeing impacts, so
the threat remains low-end and generally localized. Maintained
continuity from the previous forecast with a MRGL risk in place
across the aforementioned areas.

Kleebauer


Day 3
Valid 12Z Fri May 29 2026 - 12Z Sat May 30 2026

...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL ACROSS PORTIONS
OF THE SOUTHEAST U.S...

Strong Canadian high pressure pressing in from the north will lead
to a persistent quasi-stationary turned cold front to press south
over the course of Thursday into Friday with convection likely to
spawn along and ahead of the front with dry air advecting behind
the front leading to a cutoff of activity. Jury is still out on
specifics with the placement of the front generally over the
Carolina's by Friday morning with slow push south as the day wears
on. Frontal alignment is more of a arcing back into the Tennessee
Valley as the persistent troughing in the South-Central Plains will
likely maintain some southerly flow for areas along and west of the Mississippi. Anywhere within proximity to this front will be
subject to various convective outputs with some heavier cells
likely intertwined in over the pattern. No discernible areas of
interest are present at this juncture, however the environmental
favorability likely points to the best chances occurring across
the Southeast into the lower Tennessee Valley. A broad MRGL is
forecast for the above areas through the Lower Mississippi Valley.

Kleebauer


Day 1 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/94epoints.txt__;!!DZ3fjg!-8yJKAZc6wzUGD9JJAVeeEZfl5uZh1tTnEGJ91hAaKEF= dHE3yhgH8MRbuH2pG7ByU1wIm2o9jiVQTPXmM6F8nJ7MQaM$=20
Day 2 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/98epoints.txt__;!!DZ3fjg!-8yJKAZc6wzUGD9JJAVeeEZfl5uZh1tTnEGJ91hAaKEF= dHE3yhgH8MRbuH2pG7ByU1wIm2o9jiVQTPXmM6F8oWasIcw$=20
Day 3 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/99epoints.txt__;!!DZ3fjg!-8yJKAZc6wzUGD9JJAVeeEZfl5uZh1tTnEGJ91hAaKEF= dHE3yhgH8MRbuH2pG7ByU1wIm2o9jiVQTPXmM6F8xVLrFPY$=20

=3D =3D =3D
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FOUS30 KWBC 272000
QPFERD

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
400 PM EDT Wed May 27 2026

Day 1
Valid 16Z Wed May 27 2026 - 12Z Thu May 28 2026

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL ACROSS PORTIONS OF
SOUTHEAST TEXAS, CENTRAL GULF COAST, AND AREAS OF THE OHIO VALLEY
TO CENTRAL APPALACHIANS...

16Z update... A modest eastward adjustment of the Marginal Risk was
made across eastern Maryland and into the Virginia Outer banks and
western Delaware for ongoing convection. Refer to MPD #258 for
further details for the near-term heavy rain/flash flooding threat.
Multiple cells are expected to focus/repeat over portions of
northern West Virginia with rainfall rates upwards of 1.5-2 in/hr
this afternoon and evening which would place this part of the
region in the higher end of the flash flooding threat within the
Slight Risk area.

Campbell

12Z Special...
Minor adjustment was made to the southern extent of the Marginal
Risk across South Texas to reflect ongoing convection. Refer to MPD
#256 for further details regarding the near-term heavy rain/flash
flooding threat across this region.

Pereira

...Texas to Central Gulf Coast...

Radar this evening is pretty telling with the current evolution
over TX revealing quite the complex of thunderstorms migrating
eastward out Hill Country into the I-35 corridor. These storms will
continue to shove eastward with assistance from both a relatively
solid mean steering flow and outflow propagation stemming from the
organized convection. Aloft, two notable features are depicted via
WV satellite and UA analysis across the Southern Plains. The first
is a well-defined negatively tilted trough oriented over NM into
the TX Panhandle that will be slow to deviate from its current
positioning over the course of the D1, even some prospects of the
upper pattern closing off across the Panhandle area of TX/OK which
would allow for some general enhancement of organized convective
clusters under the primary circulation stemming from any upper
low (ULL). In any case, this general upper pattern across the
region will entice broad cyclonic flow across the south-central
portion of the CONUS leading to convective development around the
periphery of the trough/ULL with an extension of activity likely to
be situated from southeastern CO, across KS and OK, and eventually
swinging back into the Lower Mississippi Valley. Instability maxima
will still be located further to the south and east within closer
proxy to the Gulf, however the upper levels and generally above
normal PWAT anomalies over the entire scope of the Southern Plains
should still act as a favorable environment for locally heavy
rainfall leading to some flash flood prospects over the arcing area
referenced above.

That said, one of the wild cards at play in this setup is the maturation/development of any MCV structures that would locally
enhance convective episodes and likely trigger a more beneficial
low-level convergence pattern capable of better flash flood
prospects. This has been an output via some of the CAMs this
evening, most notably the HRRR where MCV development across OK
would trigger some locally enhanced precip maxima located within
the broad cyclonic presence. These features are tough to forecast
in the short term with more of a nowcasting component likely to be
instituted before committing to anything more concrete in the
forecast, so this will bear watching over the course of the D1.

The more notable feature of interest for this evening and carrying
through the D1 will likely be the evolution of a trailing vorticity
maxima ejecting out of Coahuila this evening with the current
radar/sat composite indicating a cluster of thunderstorms currently
migrating east out of the Mexican state. The current MCS over Texas
has a defined southern edge arcing back into south TX with a strong
cell currently situated above 50 miles to the east of Laredo.
Recent 00z CAMs indicate the Mexican disturbance following the tail
end of the complex over TX and focusing on a heavy rain core
trailing across south TX with a due east push of the mid-level
disturbance. Consensus on heavy rainfall for the period will begin
across southeast TX with the highlight likely to start around
Corpus Christi and surrounds with moderate to heavy rain lingering
across the Upper TX coast. As the outflow from the current complex
shoves east, the environment will become stabilized behind the
complex leading to a weakening convective regime as the disturbance
to the south begins to enter into the region. There's some
discrepancy on the specifics of the convective placement as we step
through the morning, but the trends are for the immediate TX Gulf
coast into southern LA as being the most notable areas of interest
with the evolution of expected heavy rainfall during the D1. This
is reflected well within the neighborhood prob fields off the
latest HREF signaling >3" running between 40-70% across the entire
stretch from Port O'Connor all the way towards New Orleans.
Downstream prospects are more in due part to the continued
southerly flow continuing to advect deep moisture into the region
allowing for an environment capable of producing heavy convection
during peak afternoon heating. The migration of the outflow on the
northern edge of the current complex will likely skirt the southern
portion of LA with some models maintaining its presence as far east
as southeastern LA before it finally dwindles. In any case, the
environmental favorability in the period lies within that coastal
plain where elevated theta_E's lend to a heightened threat for
heavy rainfall in anything that crops up with hourly rates likely
to reach 2-3"/hr in the heavier cell cores.

Considering the complex evolutions referenced above for both areas
of interest, the highest probabilities aligning with the Upper TX
and Central Gulf coast allows for a continued SLGT risk positioning
in these locations with a broad MRGL encompassing the overall
cyclonic pattern oriented over the Southern Plains to Lower
Mississippi Valley. Will still need to monitor the evolution
closely as deviations in the outflow positioning, or the
introduction of either closed ULL reflections or MVC's over the
Southern Plains could very well aid in additional upgrades in any
areas encompassed by these features.

...Ohio Valley to Central Appalachians...

Latest surface analysis over the Ohio Valley to Mid Atlantic
indicates a defined quasi-stationary front bisecting northern KY
through southern WV into central VA with pockets of showers
currently migrating northeast within the mean flow around a broad
ridge extension off the Atlantic seaboard. This frontal alignment
and lingering mid-level vorticity analyzed over the Ohio Valley
will lead to scattered to widespread convective regime over the
course of today with a heightened threat for locally heavy rainfall
occurring by late-morning and afternoon as environmental
destabilization takes shape. The frontal placement will be
important with regards to eventual convective initiation as this
will become a focal point for any future development over the
course of the afternoon. Model consensus is the boundary wavering
slowly to the north during the morning as a weak disturbance begins
to ride along the boundary leading to some minor regional
amplification and a slow push north of the front to about the
latitude of I-70. A sweeping trough exiting out of Ontario will
also help tighten an axis of confluence across the Midwest and
Ohio Valley by later in the afternoon, enticing a squeeze of the
thermal gradient and regional instability axis that aligns with the
frontal placement.

Instability markers by the afternoon hours will run between
2000-3000 J/kg for MUCAPE with weak shear presence leading to
scattered to widespread thunderstorm initiation along and south of
the front with generally modest cell motions to the southeast after development. PWAT anomalies will sit firmly within +2 standard
deviations above climo within the proposed area of impact, a factor
that will correlate to strong cell cores capable of heavier
downpours with hourly rates between 1-2"/hr. Previous periods of
rainfall in the last three to four days have really brought down
the areal FFG markers for all 1/3/6 hour thresholds with a vast
majority of places along the Ohio River basin and points north
running <1"/hr in the hourly exceedance indicator. This points to
any heavier convective impacts could cause issues with the remnant
soil moisture and hydrologic concerns that are lingering after the
last event. This is especially true for eastern OH, southwest PA,
and western WV where complex topography only exacerbate the
potential in these zones. The latest 00z HREF continues to paint a
favorable concept of heavier rain prospects along and south of I-70
with a corridor of heavier rainfall likely to occur over southeast
IN through southern OH into northwest WV. EAS probs for >1" are
actually pretty elevated (50-80%) in the zone along I-79 over
towards the Appalachian front in WV with modest probs of 25-40%
located along the aforementioned line extending through IN/OH. A
lot of the flash flood focus will likely correlate with the hourly
rates and overlap of heavy rain over areas still saturated from
previous periods. Considering the antecedent conditions and
expected widespread convective regime along the front, the SLGT
risk was maintained for an increasing threat for flash flooding
during the period.

...Northern Rockies...

Relatively buoyant environment within a deep, anomalous moisture
presence across the Northern Rockies along with regional ascent
provided by sheared vorticity maxima maneuvering through the area
will allow for another round of widely scattered convection to
materialize across the Lewis Range in northwest MT. Instability and
regional forcing will be a bit less than the previous period,
however sensitivities remain from remnant burn scars present
within the mountainous terrain in the aforementioned area which is
a cause for concern for any cells that happen to occur over the
burn scars themselves. Hourly rates between 0.5-1"/hr in the
stronger cell cores would be capable of providing localized flash
flood impacts over those more sensitive grounds and this setup will
maintain the prospects given the anomalous moisture presence as
PWATs remain above the 90th percentile over the entire stretch of
the Northern Rockies. The previous MRGL risk inherited was
maintained given the relative continuity.

Kleebauer


Day 2
Valid 12Z Thu May 28 2026 - 12Z Fri May 29 2026

...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL ACROSS PORTIONS
OF THE CENTRAL AND SOUTHERN PLAINS, PACIFIC NORTHWEST INTO THE=20
NORTHERN ROCKIES, LOWER MISSISSIPPI VALLEY, AND SOUTHEAST=20
FLORIDA...

...Plains to Lower Mississippi Valley...

21z update... The region with a highlighted threat for excessive=20
rainfall and isolated flash flooding remain in good order,=20
requiring no adjustments at this time.

Campbell

A bit of an omega block pattern is shaping up across the CONUS with
a broad upper trough axis fixated over the Central and Southern
Plains with with ridging in place over the top. This will cause a
rather chaotic flow under the mean trough with deep moisture and
several smaller mid-level perturbations basically "stuck" under the
the overall trough axis. Ample instability with deep moisture
presence will certain be a cause for continuing at least a
scattered heavy rain footprint across areas under the influence of
the trough. Scattered elevated probabilities between 30-60% exists
for localized amounts >2" from KS all the way into the Southeast
U.S. with the maxima split between KS and the Central Gulf coast.
The two areas are different in the reasoning as the primary center
of the trough will be fixed over KS leading to the best upper
forcing pattern and stagnant flow remaining parked over the area as
we move through D2. Pending the amount of rain that falls over the
course of D1, a targeted upgrade is possible, but maintained the
MRGL and will reassess as we move forward in future updates to see
if an upgrade is warranted. The Central Gulf coast will remain in a
favorable instability maxima with weak flow likely a component that
could lead to isolated heavy totals stemming from slow-moving
convection. The area from the Upper TX coast over through southern
GA has been leaning wet over the past week, so antecedent
conditions are a little more unforgiving for these types of setups.
In any case, the threat remains modest, at best, so the MRGL risk
was sufficient for the pattern with any upgrades likely to stem
from more near term sampling of the radar trends.

...Florida...

21Z update... No changes were made for this period.

Campbell

Active sea breeze pattern with weakening steering flow will lead
to a period of heavy rainfall across the southeast FL coast on
Thursday afternoon. Consensus within guidance is for an active
period between 18-00z Thu/Fri that would allow for heavy convection
with slow forward propagations to impact the South Florida metro
corridor from West Palm Beach down to Miami. Latest 00z HREF is
modestly robust with the signature for at least 3" off the
neighborhood probabilities with a steady 60-90% output along the
southeastern coast of FL with the maxima generally confined to the
Miami Metro up to West Palm Beach. This correlates strongly with
what has been advertised via regional and global guidance the past
few days with the deterministic CAMs even indicating some 4-6"
bullseye's within the main QPF footprint. This is a relatively
classic pattern capable of locally significant rainfall within a
deep moisture presence as PWAT anomalies sit between +1 to +2
standard deviations within the various ensemble packages. A MRGL
risk remains in effect for the period across the South Florida
metro corridor.

...Washington/Oregon into the Northern Rockies...

21Z update... A substantial expansion of the Northern Rockies
Marginal Risk was made to include most of eastern Washington up to
the Continental Divide and south into the Oregon Cascades and=20
surrounding areas on both sides of the Divide. Anomalous PW values=20
have been observed across the region, with some nearing the=20
climatology max for late May. Should thunderstorms hold together,=20
especially west of the Cascades, there will be an elevated threat=20
for local flash flooding.=20

Campbell

Maturing ULL over the west coast will allow for a broad axis of
diffluent flow across the interior northwest with the highlight of
scattered convection likely to pivot further west into eastern WA,
northern ID, and the western slopes of the Northern Rockies.
Signals are not as prevalent compared to previous periods, however
the environmental conditions are still favorable, especially when
it comes to PWAT anomalies still generally running between the
90-95th percentile across northeast WA into northern ID. Burn scar
remnants will likely be the most susceptible to seeing impacts, so
the threat remains low-end and generally localized. Maintained
continuity from the previous forecast with a MRGL risk in place
across the aforementioned areas.

Kleebauer


Day 3
Valid 12Z Fri May 29 2026 - 12Z Sat May 30 2026

...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL ACROSS PORTIONS
OF THE SOUTHEAST U.S. AND FOR EASTERN WASHINGTON INTO THE NORTHERN
ROCKIES...

21z update... A Marginal Risk was raised for portions of eastern
Washington, northern Idaho and northwest Montana where there has
been an elevated threat for localized excessive rainfall and
isolated flash flooding as described in the Day 1 and Day 2
sections. Guidance is signaling a notable increase in QPF amounts=20
and coverage for parts of northern Idaho and into Montana, thus
continuing the flooding threat for this time period.

Further south, guidance still varied on where the highest QPF was
placed; however there was consensus for an increase in amounts=20
across southern Missouri, central/eastern Tennessee and western=20
South Carolina. This trend supported an adjustment of the northern
boundary of the Marginal Risk area.

Campbell

Strong Canadian high pressure pressing in from the north will lead
to a persistent quasi-stationary turned cold front to press south
over the course of Thursday into Friday with convection likely to
spawn along and ahead of the front with dry air advecting behind
the front leading to a cutoff of activity. Jury is still out on
specifics with the placement of the front generally over the
Carolina's by Friday morning with slow push south as the day wears
on. Frontal alignment is more of a arcing back into the Tennessee
Valley as the persistent troughing in the South-Central Plains will
likely maintain some southerly flow for areas along and west of the Mississippi. Anywhere within proximity to this front will be
subject to various convective outputs with some heavier cells
likely intertwined in over the pattern. No discernible areas of
interest are present at this juncture, however the environmental
favorability likely points to the best chances occurring across
the Southeast into the lower Tennessee Valley. A broad MRGL is
forecast for the above areas through the Lower Mississippi Valley.

Kleebauer


Day 1 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/94epoints.txt__;!!DZ3fjg!5yj2em7sTq2jXfUJLzuQZZxF0ebB7IVqFBCKwz7gqjwl= X17Z3ZYHo7-nuoWvjAJ5PAQWspdK8QFp327uCrP1IXWeVko$=20
Day 2 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/98epoints.txt__;!!DZ3fjg!5yj2em7sTq2jXfUJLzuQZZxF0ebB7IVqFBCKwz7gqjwl= X17Z3ZYHo7-nuoWvjAJ5PAQWspdK8QFp327uCrP1a5Kx-yM$=20
Day 3 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/99epoints.txt__;!!DZ3fjg!5yj2em7sTq2jXfUJLzuQZZxF0ebB7IVqFBCKwz7gqjwl= X17Z3ZYHo7-nuoWvjAJ5PAQWspdK8QFp327uCrP1vzqJ7CA$=20

=3D =3D =3D
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FOUS30 KWBC 280054
QPFERD

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
854 PM EDT Wed May 27 2026

Day 1
Valid 01Z Thu May 28 2026 - 12Z Thu May 28 2026

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL ACROSS PORTIONS OF
WEST VIRGINIA AND ACROSS SOUTHWEST LOUISIANA...

...0100 UTC Update...

Have trimmed quite a bit of real estate with both the Slight and
Marginal areas, based on the latest observational trends, including mesoanalysis (dCAPE/dt), along with the recent HRRRs and 18Z HREF
QPF exceedance probabilities. The remaining Slight Risk area over
central WV (and a small sliver of northeast KY/southeast OH) is
essentially for the near term...through 03-04Z...given the current
radar trends and lingering deep-layer instability (MUCAPEs ~1000
J/Kg). The other remaining Slight Risk area (southwest LA) was
supported by the latest HREF and RRFS exceedance probabilities,
along with the recent HRRR output.

Hurley

Elsewhere (Northern Rockies), the Marginal Risk area remains
(previous discussion below)...

Relatively buoyant environment within a deep, anomalous moisture=20
presence across the Northern Rockies along with regional ascent=20
provided by sheared vorticity maxima maneuvering through the area=20
will allow for another round of widely scattered convection to=20
materialize across the Lewis Range in northwest MT. Instability and
regional forcing will be a bit less than the previous period,=20
however sensitivities remain from remnant burn scars present within
the mountainous terrain in the aforementioned area which is a=20
cause for concern for any cells that happen to occur over the burn=20
scars themselves. Hourly rates between 0.5-1"/hr in the stronger=20
cell cores would be capable of providing localized flash flood=20
impacts over those more sensitive grounds and this setup will=20
maintain the prospects given the anomalous moisture presence as=20
PWATs remain above the 90th percentile over the entire stretch of=20
the Northern Rockies. The previous MRGL risk inherited was=20
maintained given the relative continuity.

Kleebauer


Day 2
Valid 12Z Thu May 28 2026 - 12Z Fri May 29 2026

...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL ACROSS PORTIONS
OF THE CENTRAL AND SOUTHERN PLAINS, PACIFIC NORTHWEST INTO THE
NORTHERN ROCKIES, LOWER MISSISSIPPI VALLEY, AND SOUTHEAST
FLORIDA...

...Plains to Lower Mississippi Valley...

21z update... The region with a highlighted threat for excessive
rainfall and isolated flash flooding remain in good order,
requiring no adjustments at this time.

Campbell

A bit of an omega block pattern is shaping up across the CONUS with
a broad upper trough axis fixated over the Central and Southern
Plains with with ridging in place over the top. This will cause a
rather chaotic flow under the mean trough with deep moisture and
several smaller mid-level perturbations basically "stuck" under the
the overall trough axis. Ample instability with deep moisture
presence will certain be a cause for continuing at least a
scattered heavy rain footprint across areas under the influence of
the trough. Scattered elevated probabilities between 30-60% exists
for localized amounts >2" from KS all the way into the Southeast
U.S. with the maxima split between KS and the Central Gulf coast.
The two areas are different in the reasoning as the primary center
of the trough will be fixed over KS leading to the best upper
forcing pattern and stagnant flow remaining parked over the area as
we move through D2. Pending the amount of rain that falls over the
course of D1, a targeted upgrade is possible, but maintained the
MRGL and will reassess as we move forward in future updates to see
if an upgrade is warranted. The Central Gulf coast will remain in a
favorable instability maxima with weak flow likely a component that
could lead to isolated heavy totals stemming from slow-moving
convection. The area from the Upper TX coast over through southern
GA has been leaning wet over the past week, so antecedent
conditions are a little more unforgiving for these types of setups.
In any case, the threat remains modest, at best, so the MRGL risk
was sufficient for the pattern with any upgrades likely to stem
from more near term sampling of the radar trends.

...Florida...

21Z update... No changes were made for this period.

Campbell

Active sea breeze pattern with weakening steering flow will lead
to a period of heavy rainfall across the southeast FL coast on
Thursday afternoon. Consensus within guidance is for an active
period between 18-00z Thu/Fri that would allow for heavy convection
with slow forward propagations to impact the South Florida metro
corridor from West Palm Beach down to Miami. Latest 00z HREF is
modestly robust with the signature for at least 3" off the
neighborhood probabilities with a steady 60-90% output along the
southeastern coast of FL with the maxima generally confined to the
Miami Metro up to West Palm Beach. This correlates strongly with
what has been advertised via regional and global guidance the past
few days with the deterministic CAMs even indicating some 4-6"
bullseye's within the main QPF footprint. This is a relatively
classic pattern capable of locally significant rainfall within a
deep moisture presence as PWAT anomalies sit between +1 to +2
standard deviations within the various ensemble packages. A MRGL
risk remains in effect for the period across the South Florida
metro corridor.

...Washington/Oregon into the Northern Rockies...

21Z update... A substantial expansion of the Northern Rockies
Marginal Risk was made to include most of eastern Washington up to
the Continental Divide and south into the Oregon Cascades and
surrounding areas on both sides of the Divide. Anomalous PW values
have been observed across the region, with some nearing the
climatology max for late May. Should thunderstorms hold together,
especially west of the Cascades, there will be an elevated threat
for local flash flooding.

Campbell

Maturing ULL over the west coast will allow for a broad axis of
diffluent flow across the interior northwest with the highlight of
scattered convection likely to pivot further west into eastern WA,
northern ID, and the western slopes of the Northern Rockies.
Signals are not as prevalent compared to previous periods, however
the environmental conditions are still favorable, especially when
it comes to PWAT anomalies still generally running between the
90-95th percentile across northeast WA into northern ID. Burn scar
remnants will likely be the most susceptible to seeing impacts, so
the threat remains low-end and generally localized. Maintained
continuity from the previous forecast with a MRGL risk in place
across the aforementioned areas.

Kleebauer


Day 3
Valid 12Z Fri May 29 2026 - 12Z Sat May 30 2026

...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL ACROSS PORTIONS
OF THE SOUTHEAST U.S. AND FOR EASTERN WASHINGTON INTO THE NORTHERN
ROCKIES...

21z update... A Marginal Risk was raised for portions of eastern
Washington, northern Idaho and northwest Montana where there has
been an elevated threat for localized excessive rainfall and
isolated flash flooding as described in the Day 1 and Day 2
sections. Guidance is signaling a notable increase in QPF amounts
and coverage for parts of northern Idaho and into Montana, thus
continuing the flooding threat for this time period.

Further south, guidance still varied on where the highest QPF was
placed; however there was consensus for an increase in amounts
across southern Missouri, central/eastern Tennessee and western
South Carolina. This trend supported an adjustment of the northern
boundary of the Marginal Risk area.

Campbell

Strong Canadian high pressure pressing in from the north will lead
to a persistent quasi-stationary turned cold front to press south
over the course of Thursday into Friday with convection likely to
spawn along and ahead of the front with dry air advecting behind
the front leading to a cutoff of activity. Jury is still out on
specifics with the placement of the front generally over the
Carolina's by Friday morning with slow push south as the day wears
on. Frontal alignment is more of a arcing back into the Tennessee
Valley as the persistent troughing in the South-Central Plains will
likely maintain some southerly flow for areas along and west of the Mississippi. Anywhere within proximity to this front will be
subject to various convective outputs with some heavier cells
likely intertwined in over the pattern. No discernible areas of
interest are present at this juncture, however the environmental
favorability likely points to the best chances occurring across
the Southeast into the lower Tennessee Valley. A broad MRGL is
forecast for the above areas through the Lower Mississippi Valley.

Kleebauer


Day 1 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/94epoints.txt__;!!DZ3fjg!7tUfWqqUeqFMBccGFZelwSR1F32kIUZycXlDz4scVJYG= OB7encO21_oSFocdLVZhLhcKbxwcq5Wj5JUfV7IrZE2tarw$=20
Day 2 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/98epoints.txt__;!!DZ3fjg!7tUfWqqUeqFMBccGFZelwSR1F32kIUZycXlDz4scVJYG= OB7encO21_oSFocdLVZhLhcKbxwcq5Wj5JUfV7Ir-CiWWcQ$=20
Day 3 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/99epoints.txt__;!!DZ3fjg!7tUfWqqUeqFMBccGFZelwSR1F32kIUZycXlDz4scVJYG= OB7encO21_oSFocdLVZhLhcKbxwcq5Wj5JUfV7IrqXGPscE$=20

=3D =3D =3D
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FOUS30 KWBC 280721
QPFERD

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
321 AM EDT Thu May 28 2026

Day 1 Valid 12Z Thu May 28 2026 - 12Z Fri May 29 2026

...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL ACROSS MUCH OF=20
THE SOUTHEAST TO MIDDLE MISSISSIPPI VALLEY, SOUTHEAST FLORIDA, AND=20
FOR PORTIONS OF THE NORTHWEST...

...Central Plains to Southeast...

A bit of an omega block pattern is shaping up across the CONUS=20
with a broad upper trough axis fixated over the Central and=20
Southern Plains with ridging in place over the top. This will cause
a rather chaotic flow under the mean trough and several smaller=20
mid- level perturbations basically "stuck" within the overall=20
trough axis. Ample instability with deep moisture presence will=20
certainly continue to support at least a scattered heavy rain=20
footprint across areas underneath influence of the trough.=20
Scattered elevated probabilities between 30-70% exists for=20
localized amounts >3" from KS all the way into the Southeast U.S.=20
with the maxima split between eastern KS to northern AR and the=20
Central Gulf coast. For KS/AR, parked underneath the upper trough,=20
upper forcing and stagnant flow are more favorable for heavier=20
rainfall totals. Maintaining a marginal risk at this time as the=20
heaviest rainfall over the past 12 or so hours was more southwest=20
of where the guidance is showing today and the rest of the region=20
is still somewhat dry and can probably support some heavier totals.
Along the Gulf Coast and into the Southeast, instability will be=20
maximized in this area with weak flow supporting slow- moving=20
convection and heavier rainfall over those isolated areas.=20
Antecedent conditions across much of this region are also very wet,
so it may not take much to cause issue. Given the still fairly=20
isolated nature, maintaining a broad marginal risk, with any=20
possible upgrades today stemming more from near term radar trends.=20

...Florida...

An active sea breeze pattern with weakening steering flow will=20
lead to periods of heavy rainfall across southeast Florida this=20
afternoon. Greatest concern remains over the South Florida metro=20
corridor from West Palm Beach to Miami. Latest HREF is robust with=20
showing greater than 50% probabilities for 3" in 24-hours, with=20
even some modest, albeit localized, probabilities for 5". This=20
correlates well with CAM guidance, with some indicating bullseyes=20
of greater than 3" within the larger QPF footprint. Locally=20
significant rainfall is likely in this relatively classic pattern=20
with ample moisture and instability present. A marginal risk=20
remains in effect across Southeast Florida.=20

...Washington/Oregon...

A deep upper level low over the West will allow for a broad axis=20
of diffluent flow across the interior Northwest. Precipitable water
values 1-1.5" are in the 90-90th percentile, and with sufficient=20 instability, should support convection capable of producing heavy=20
rainfall. Flooding and flash flooding are a concern for mainly the=20
more vulnerable areas - urban, small stream, and low lying areas.=20
HREF 24-hr probabilities for greater than 3" are between 40-70% for
especially the Oregon cascades. Given the favorable environment=20
though, a marginal risk extends all the way from far northern=20
California northward to the eastern half of Washington state. A=20
previous marginal risk for parts of the northern Rockies was=20
trimmed out for this update given the lack of QPF signal.

Santorelli


Day 2 Valid 12Z Fri May 29 2026 - 12Z Sat May 30 2026

...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL ACROSS PARTS OF=20
THE NORTHERN ROCKIES AS WELL AS MUCH OF THE SOUTHEAST TO MIDDLE=20
MISSISSIPPI VALLEY...

...Eastern Washington to Northern Rockies...

A marginal risk is in place across far northeast Washington to=20
northwest Montana due to an increase in the heavy rainfall signal=20
for this period as the upper low over the West on Day 1, pivots=20
slightly northeastward, placing this region in an area with better=20
upper forcing and advection of moisture. The presence of anomalous=20
moisture and some instability may present a threat for localized=20
heavy rainfall and flash flooding, especially for burn scar=20
locations within this region.=20

...Middle Mississippi Valley to the Southeast...

Strong Canadian high pressure pressing in from the north will=20
allow for a slow moving cold front to press south over the course=20
of Thursday into Friday with convection likely to spawn along and=20
ahead of the front and dry air advecting behind the front leading=20
to a quick cutoff of activity. The front will arc back into the=20
Tennessee Valley to Middle Mississippi Valley, supported by the=20
persistent troughing over the south-central Plains. A moist and=20
unstable environment near and south of this front will support=20
scattered convection, with some heavier cells likely within the=20
pattern. It is still too hard to pick out any discernible areas of=20
interest, so maintained a very broad marginal risk over this area=20
which is quite wet and will continue to be in the Day 1 period.

Santorelli


Day 3 Valid 12Z Sat May 30 2026 - 12Z Sun May 31 2026

...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL ACROSS THE=20
NORTHERN ROCKIES TO HIGH PLAINS AND THE SOUTHEAST...

...Northern Rockies to High Plains...

The upper level low over the West during the Day 1 and 2 periods=20
will weaken and shift northeastward, moving over the Northern=20
Rockies to High Plains region on Day 3/Saturday. Moisture anomalies
will continue to be in the 90-90th percentile, supporting moderate
to heavy rainfall, with widespread QPF greater than 0.5-1" likely=20
across western and central Montana. There may not be a lot of=20
instability to work with, so any flood or flash flood threats=20
should be mainly localized with particular attention to burn scar=20
locations. A fairly broad marginal risk is in place across much of=20
western and central Montana, into parts of northern Wyoming as=20
well.

...Southeast...

Same story as Days 1 and 2, with ample moisture and instability=20
present near and south of a cold front that may stall over the=20
region on Saturday supporting convection, across much of the=20
Southeast. Some of this region, especially western parts of South=20
Carolina and into the Appalachians has been very wet as of late and
is well primed, so may be more favorable for flooding concerns.=20
The marginal risk though continues towards the coast due to the=20
presence of a weak frontal wave in the region. The Marginal Risk=20
extends from the Southeast coast, westward into northeast Alabama=20
and southeast Tennessee.=20

Santorelli



Day 1 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/94epoints.txt__;!!DZ3fjg!-YssY9nv8nNmRWt9Iy4hs-WJzue9EUqyhWBfiUQAj2Mm= jm7shMhPqRSxkaqTtxJPiBQQ4eYOipJmw8XpHK0_TuDwfxo$=20
Day 2 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/98epoints.txt__;!!DZ3fjg!-YssY9nv8nNmRWt9Iy4hs-WJzue9EUqyhWBfiUQAj2Mm= jm7shMhPqRSxkaqTtxJPiBQQ4eYOipJmw8XpHK0_JVzP_k8$=20
Day 3 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/99epoints.txt__;!!DZ3fjg!-YssY9nv8nNmRWt9Iy4hs-WJzue9EUqyhWBfiUQAj2Mm= jm7shMhPqRSxkaqTtxJPiBQQ4eYOipJmw8XpHK0_548tKWQ$=20

=3D =3D =3D
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FOUS30 KWBC 280734=20
QPFERD

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
334 AM EDT Thu May 28 2026

Day 1=20
Valid 12Z Thu May 28 2026 - 12Z Fri May 29 2026

...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL ACROSS MUCH OF=20
THE SOUTHEAST TO MIDDLE MISSISSIPPI VALLEY, SOUTHEAST FLORIDA, AND=20
FOR PORTIONS OF THE NORTHWEST...

...Central Plains to Southeast...

A bit of an omega block pattern is shaping up across the CONUS=20
with a broad upper trough axis fixated over the Central and=20
Southern Plains with ridging in place over the top. This will cause
a rather chaotic flow under the mean trough and several smaller=20
mid- level perturbations basically "stuck" within the overall=20
trough axis. Ample instability with deep moisture presence will=20
certainly continue to support at least a scattered heavy rain=20
footprint across areas underneath influence of the trough.=20
Scattered elevated probabilities between 30-70% exists for=20
localized amounts >3" from KS all the way into the Southeast U.S.=20
with the maxima split between eastern KS to northern AR and the=20
Central Gulf coast. For KS/AR, parked underneath the upper trough,=20
upper forcing and stagnant flow are more favorable for heavier=20
rainfall totals. Maintaining a marginal risk at this time as the=20
heaviest rainfall over the past 12 or so hours was more southwest=20
of where the guidance is showing today and the rest of the region=20
is still somewhat dry and can probably support some heavier totals.
Along the Gulf Coast and into the Southeast, instability will be=20
maximized in this area with weak flow supporting slow- moving=20
convection and heavier rainfall over those isolated areas.=20
Antecedent conditions across much of this region are also very wet,
so it may not take much to cause issue. Given the still fairly=20
isolated nature, maintaining a broad marginal risk, with any=20
possible upgrades today stemming more from near term radar trends.=20

...Florida...

An active sea breeze pattern with weakening steering flow will=20
lead to periods of heavy rainfall across southeast Florida this=20
afternoon. Greatest concern remains over the South Florida metro=20
corridor from West Palm Beach to Miami. Latest HREF is robust with=20
showing greater than 50% probabilities for 3" in 24-hours, with=20
even some modest, albeit localized, probabilities for 5". This=20
correlates well with CAM guidance, with some indicating bullseyes=20
of greater than 3" within the larger QPF footprint. Locally=20
significant rainfall is likely in this relatively classic pattern=20
with ample moisture and instability present. A marginal risk=20
remains in effect across Southeast Florida.=20

...Washington/Oregon...

A deep upper level low over the West will allow for a broad axis=20
of diffluent flow across the interior Northwest. Precipitable water
values 1-1.5" are in the 90-90th percentile, and with sufficient=20 instability, should support convection capable of producing heavy=20
rainfall. Flooding and flash flooding are a concern for mainly the=20
more vulnerable areas - urban, small stream, and low lying areas.=20
HREF 24-hr probabilities for greater than 3" are between 40-70% for
especially the Oregon cascades. Given the favorable environment=20
though, a marginal risk extends all the way from far northern=20
California northward to the eastern half of Washington state. A=20
previous marginal risk for parts of the northern Rockies was=20
trimmed out for this update given the lack of QPF signal.

Santorelli


Day 2=20
Valid 12Z Fri May 29 2026 - 12Z Sat May 30 2026

...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL ACROSS PARTS OF=20
THE NORTHERN ROCKIES AS WELL AS MUCH OF THE SOUTHEAST TO MIDDLE=20
MISSISSIPPI VALLEY...

...Eastern Washington to Northern Rockies...

A marginal risk is in place across far northeast Washington to=20
northwest Montana due to an increase in the heavy rainfall signal=20
for this period as the upper low over the West on Day 1, pivots=20
slightly northeastward, placing this region in an area with better=20
upper forcing and advection of moisture. The presence of anomalous=20
moisture and some instability may present a threat for localized=20
heavy rainfall and flash flooding, especially for burn scar=20
locations within this region.=20

...Middle Mississippi Valley to the Southeast...

Strong Canadian high pressure pressing in from the north will=20
allow for a slow moving cold front to press south over the course=20
of Thursday into Friday with convection likely to spawn along and=20
ahead of the front and dry air advecting behind the front leading=20
to a quick cutoff of activity. The front will arc back into the=20
Tennessee Valley to Middle Mississippi Valley, supported by the=20
persistent troughing over the south-central Plains. A moist and=20
unstable environment near and south of this front will support=20
scattered convection, with some heavier cells likely within the=20
pattern. It is still too hard to pick out any discernible areas of=20
interest, so maintained a very broad marginal risk over this area=20
which is quite wet and will continue to be in the Day 1 period.

Santorelli


Day 3=20
Valid 12Z Sat May 30 2026 - 12Z Sun May 31 2026

...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL ACROSS THE=20
NORTHERN ROCKIES TO HIGH PLAINS AND THE SOUTHEAST...

...Northern Rockies to High Plains...

The upper level low over the West during the Day 1 and 2 periods=20
will weaken and shift northeastward, moving over the Northern=20
Rockies to High Plains region on Day 3/Saturday. Moisture anomalies
will continue to be in the 90-90th percentile, supporting moderate
to heavy rainfall, with widespread QPF greater than 0.5-1" likely=20
across western and central Montana. There may not be a lot of=20
instability to work with, so any flood or flash flood threats=20
should be mainly localized with particular attention to burn scar=20
locations. A fairly broad marginal risk is in place across much of=20
western and central Montana, into parts of northern Wyoming as=20
well.

...Southeast...

Same story as Days 1 and 2, with ample moisture and instability=20
present near and south of a cold front that may stall over the=20
region on Saturday supporting convection, across much of the=20
Southeast. Some of this region, especially western parts of South=20
Carolina and into the Appalachians has been very wet as of late and
is well primed, so may be more favorable for flooding concerns.=20
The marginal risk though continues towards the coast due to the=20
presence of a weak frontal wave in the region. The Marginal Risk=20
extends from the Southeast coast, westward into northeast Alabama=20
and southeast Tennessee.=20

Santorelli


Day 1 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/94epoints.txt__;!!DZ3fjg!4S4m498bm9JZqtey54vA7g3YIEMhtMsEwPHurMkE1cTF= J6alatFR33U3zbQbPFdJZ4265Tyx9piJmqI6sbUDbu7dhhQ$=20
Day 2 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/98epoints.txt__;!!DZ3fjg!4S4m498bm9JZqtey54vA7g3YIEMhtMsEwPHurMkE1cTF= J6alatFR33U3zbQbPFdJZ4265Tyx9piJmqI6sbUD579Gtl4$=20
Day 3 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/99epoints.txt__;!!DZ3fjg!4S4m498bm9JZqtey54vA7g3YIEMhtMsEwPHurMkE1cTF= J6alatFR33U3zbQbPFdJZ4265Tyx9piJmqI6sbUD-Ft8gWE$=20

=3D =3D =3D
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FOUS30 KWBC 281558
QPFERD

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
1158 AM EDT Thu May 28 2026

Day 1
Valid 16Z Thu May 28 2026 - 12Z Fri May 29 2026

...THERE ARE SLIGHTS RISKS OF EXCESSIVE RAINFALL ALONG THE CENTRAL
GULF COAST, CENTRAL KANSAS, AND IN THE OZARKS OF MISSOURI AND=20
ARKANSAS...

16Z Update...

Slight Risks were introduced for the 16Z update in parts of the
central KS, the Ozarks, and along the central Gulf Coast. The
Marginal Risks in the Pacific NW and South FL remain in good shape.

...Central Gulf Coast...

The 12Z LIX sounding was effectively a tropical sounding with=20
plenty of MLCAPE present (>2,000 J/kg). Winds within the depth of=20
the cloud layer were almost uniformly out of the south with=20
training thunderstorms a concern from NOLA non north and east along
the I-59 corridor. Soils remain highly saturated and primed for=20
flash flooding with rainfall rates that could top 3"/hr in the=20
heaviest thunderstorm activity. Storms are at least moving along at
a steady clip, which should help to reduce the areal extent for=20
flash flooding. That said, these storms may exacerbate the flooding
the region has experienced in recent days. For these reasons, a=20
Slight Risk was introduced.

...Ozarks & Central Arkansas...

A narrow NW-SE corridor of anomalous PWs (>2.0" PWs that top the
99.5 climatological percentile per ECMWF) is caught between a
strong ridge of high pressure in the Upper MS Valley and a
negatively tilted 850-300mb trough oriented from southern KS to the
ArkLaTex. Strong vertical ascent ahead of the 850-300mb trough
axis coupled with MLCAPE between 500-1,000 J/kg will give more
support to these highly saturated profiles. Area-averaged=20
soundings over northern AR show >85% RH values between 1000-500mb=20
and warm cloud layers >13,000ft this afternoon and evening. Soils=20
are most sensitive in central AR, while the Ozarks are historically
a "flashy" area that, even with some drier soil moisture values in
southern MO are prone to flash flooding given rainfall rates could
surpass 2"/hr. The 12Z HREF does show high chance probabilities=20

70%) for rainfall amounts >3" in southwest MO and northern AR,=20

with low chance probabilities (20-35%) for >5" amounts. In=20
collaboration with WFOs in northern AR and southern MO, opted to=20
upgrade to a Slight Risk for the 16Z update.

...Central KS...

A pivoting 700mb low rotating through southern KS will direct a=20
plume of highly anomalous moisture for late May/early June over the
heart of KS. Per RAP mesoanalysis, PWs are already >1.5" and could
surpass 1.75" this afternoon. Central KS is ideally placed just=20
ahead of a negatively tilted 850-300mb trough that is generating=20
excellent upper-level divergence. Additional storms will form this=20
afternoon with HRRR area-averaged soundings showing >500 J/kg of=20
MLCAPE, >85% RH values within the mean 1000-500mb layer, and warm=20
cloud layers up to 12,000ft deep. Wind more uniformly out of the SE
are also supporting the potential for training storms, evident=20
from upshear corfidi vectors that are as low as 10 kts. New 12Z=20
HREF probabilities show high chance (>70%) for rainfall totals >3"=20
from Wichita on north and west with low-to-moderate chances=20
(20-40%) for localized amounts >5". Soils in the area are parched,=20
but these kind of rates can still support flash flooding,=20
particularly where repeating rounds of storms occur and in more
urbanized settings. In collaboration with ICT, decided to upgrade=20
to a Slight Risk for the 16Z update.=20

Mullinax

---Previous Discussion---

...Florida...

An active sea breeze pattern with weakening steering flow will
lead to periods of heavy rainfall across southeast Florida this
afternoon. Greatest concern remains over the South Florida metro
corridor from West Palm Beach to Miami. Latest HREF is robust with
showing greater than 50% probabilities for 3" in 24-hours, with
even some modest, albeit localized, probabilities for 5". This
correlates well with CAM guidance, with some indicating bullseyes
of greater than 3" within the larger QPF footprint. Locally
significant rainfall is likely in this relatively classic pattern
with ample moisture and instability present. A marginal risk
remains in effect across Southeast Florida.

...Washington/Oregon...

A deep upper level low over the West will allow for a broad axis
of diffluent flow across the interior Northwest. Precipitable water
values 1-1.5" are in the 90-90th percentile, and with sufficient
instability, should support convection capable of producing heavy
rainfall. Flooding and flash flooding are a concern for mainly the
more vulnerable areas - urban, small stream, and low lying areas.
HREF 24-hr probabilities for greater than 3" are between 40-70% for
especially the Oregon cascades. Given the favorable environment
though, a marginal risk extends all the way from far northern
California northward to the eastern half of Washington state. A
previous marginal risk for parts of the northern Rockies was
trimmed out for this update given the lack of QPF signal.

Santorelli


Day 2
Valid 12Z Fri May 29 2026 - 12Z Sat May 30 2026

...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL ACROSS PARTS OF
THE NORTHERN ROCKIES AS WELL AS MUCH OF THE SOUTHEAST TO MIDDLE
MISSISSIPPI VALLEY...

...Eastern Washington to Northern Rockies...

A marginal risk is in place across far northeast Washington to
northwest Montana due to an increase in the heavy rainfall signal
for this period as the upper low over the West on Day 1, pivots
slightly northeastward, placing this region in an area with better
upper forcing and advection of moisture. The presence of anomalous
moisture and some instability may present a threat for localized
heavy rainfall and flash flooding, especially for burn scar
locations within this region.

...Middle Mississippi Valley to the Southeast...

Strong Canadian high pressure pressing in from the north will
allow for a slow moving cold front to press south over the course
of Thursday into Friday with convection likely to spawn along and
ahead of the front and dry air advecting behind the front leading
to a quick cutoff of activity. The front will arc back into the
Tennessee Valley to Middle Mississippi Valley, supported by the
persistent troughing over the south-central Plains. A moist and
unstable environment near and south of this front will support
scattered convection, with some heavier cells likely within the
pattern. It is still too hard to pick out any discernible areas of
interest, so maintained a very broad marginal risk over this area
which is quite wet and will continue to be in the Day 1 period.

Santorelli


Day 3
Valid 12Z Sat May 30 2026 - 12Z Sun May 31 2026

...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL ACROSS THE
NORTHERN ROCKIES TO HIGH PLAINS AND THE SOUTHEAST...

...Northern Rockies to High Plains...

The upper level low over the West during the Day 1 and 2 periods
will weaken and shift northeastward, moving over the Northern
Rockies to High Plains region on Day 3/Saturday. Moisture anomalies
will continue to be in the 90-90th percentile, supporting moderate
to heavy rainfall, with widespread QPF greater than 0.5-1" likely
across western and central Montana. There may not be a lot of
instability to work with, so any flood or flash flood threats
should be mainly localized with particular attention to burn scar
locations. A fairly broad marginal risk is in place across much of
western and central Montana, into parts of northern Wyoming as
well.

...Southeast...

Same story as Days 1 and 2, with ample moisture and instability
present near and south of a cold front that may stall over the
region on Saturday supporting convection, across much of the
Southeast. Some of this region, especially western parts of South
Carolina and into the Appalachians has been very wet as of late and
is well primed, so may be more favorable for flooding concerns.
The marginal risk though continues towards the coast due to the
presence of a weak frontal wave in the region. The Marginal Risk
extends from the Southeast coast, westward into northeast Alabama
and southeast Tennessee.

Santorelli


Day 1 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/94epoints.txt__;!!DZ3fjg!4fwOagQdvMAvdhwdiWuACYpzSRpajxTud1ZSNHEoICMB= KaGZTX_8w1-Yt_3v1NQmkPXRbOI22hCVWe1Tb7hPMHp2Yok$=20
Day 2 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/98epoints.txt__;!!DZ3fjg!4fwOagQdvMAvdhwdiWuACYpzSRpajxTud1ZSNHEoICMB= KaGZTX_8w1-Yt_3v1NQmkPXRbOI22hCVWe1Tb7hPRCwgUmM$=20
Day 3 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/99epoints.txt__;!!DZ3fjg!4fwOagQdvMAvdhwdiWuACYpzSRpajxTud1ZSNHEoICMB= KaGZTX_8w1-Yt_3v1NQmkPXRbOI22hCVWe1Tb7hPZvQTtL8$=20

=3D =3D =3D
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FOUS30 KWBC 281959
QPFERD

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
359 PM EDT Thu May 28 2026

Day 1
Valid 16Z Thu May 28 2026 - 12Z Fri May 29 2026

...THERE ARE SLIGHTS RISKS OF EXCESSIVE RAINFALL ALONG THE CENTRAL
GULF COAST, CENTRAL KANSAS, AND IN THE OZARKS OF MISSOURI AND
ARKANSAS...

16Z Update...

Slight Risks were introduced for the 16Z update in parts of the
central KS, the Ozarks, and along the central Gulf Coast. The
Marginal Risks in the Pacific NW and South FL remain in good shape.

...Central Gulf Coast...

The 12Z LIX sounding was effectively a tropical sounding with
plenty of MLCAPE present (>2,000 J/kg). Winds within the depth of
the cloud layer were almost uniformly out of the south with
training thunderstorms a concern from NOLA non north and east along
the I-59 corridor. Soils remain highly saturated and primed for
flash flooding with rainfall rates that could top 3"/hr in the
heaviest thunderstorm activity. Storms are at least moving along at
a steady clip, which should help to reduce the areal extent for
flash flooding. That said, these storms may exacerbate the flooding
the region has experienced in recent days. For these reasons, a
Slight Risk was introduced.

...Ozarks & Central Arkansas...

A narrow NW-SE corridor of anomalous PWs (>2.0" PWs that top the
99.5 climatological percentile per ECMWF) is caught between a
strong ridge of high pressure in the Upper MS Valley and a
negatively tilted 850-300mb trough oriented from southern KS to the
ArkLaTex. Strong vertical ascent ahead of the 850-300mb trough
axis coupled with MLCAPE between 500-1,000 J/kg will give more
support to these highly saturated profiles. Area-averaged
soundings over northern AR show >85% RH values between 1000-500mb
and warm cloud layers >13,000ft this afternoon and evening. Soils
are most sensitive in central AR, while the Ozarks are historically
a "flashy" area that, even with some drier soil moisture values in
southern MO are prone to flash flooding given rainfall rates could
surpass 2"/hr. The 12Z HREF does show high chance probabilities

70%) for rainfall amounts >3" in southwest MO and northern AR,

with low chance probabilities (20-35%) for >5" amounts. In
collaboration with WFOs in northern AR and southern MO, opted to
upgrade to a Slight Risk for the 16Z update.

...Central KS...

A pivoting 700mb low rotating through southern KS will direct a
plume of highly anomalous moisture for late May/early June over the
heart of KS. Per RAP mesoanalysis, PWs are already >1.5" and could
surpass 1.75" this afternoon. Central KS is ideally placed just
ahead of a negatively tilted 850-300mb trough that is generating
excellent upper-level divergence. Additional storms will form this
afternoon with HRRR area-averaged soundings showing >500 J/kg of
MLCAPE, >85% RH values within the mean 1000-500mb layer, and warm
cloud layers up to 12,000ft deep. Wind more uniformly out of the SE
are also supporting the potential for training storms, evident
from upshear corfidi vectors that are as low as 10 kts. New 12Z
HREF probabilities show high chance (>70%) for rainfall totals >3"
from Wichita on north and west with low-to-moderate chances
(20-40%) for localized amounts >5". Soils in the area are parched,
but these kind of rates can still support flash flooding,
particularly where repeating rounds of storms occur and in more
urbanized settings. In collaboration with ICT, decided to upgrade
to a Slight Risk for the 16Z update.

Mullinax

---Previous Discussion---

...Florida...

An active sea breeze pattern with weakening steering flow will
lead to periods of heavy rainfall across southeast Florida this
afternoon. Greatest concern remains over the South Florida metro
corridor from West Palm Beach to Miami. Latest HREF is robust with
showing greater than 50% probabilities for 3" in 24-hours, with
even some modest, albeit localized, probabilities for 5". This
correlates well with CAM guidance, with some indicating bullseyes
of greater than 3" within the larger QPF footprint. Locally
significant rainfall is likely in this relatively classic pattern
with ample moisture and instability present. A marginal risk
remains in effect across Southeast Florida.

...Washington/Oregon...

A deep upper level low over the West will allow for a broad axis
of diffluent flow across the interior Northwest. Precipitable water
values 1-1.5" are in the 90-90th percentile, and with sufficient
instability, should support convection capable of producing heavy
rainfall. Flooding and flash flooding are a concern for mainly the
more vulnerable areas - urban, small stream, and low lying areas.
HREF 24-hr probabilities for greater than 3" are between 40-70% for
especially the Oregon cascades. Given the favorable environment
though, a marginal risk extends all the way from far northern
California northward to the eastern half of Washington state. A
previous marginal risk for parts of the northern Rockies was
trimmed out for this update given the lack of QPF signal.

Santorelli


Day 2
Valid 12Z Fri May 29 2026 - 12Z Sat May 30 2026

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL ACROSS PORTIONS OF
THE SOUTHEAST...

20Z Update...

In collaboration with several Southeast WFOs, a Slight Risk was=20
introduced from eastern AL to the GA/SC border. The region is=20
caught out ahead of a sheared 500mb vorticity maximum approaching=20
from the west. This feature is caught between a closed low=20
traversing the Great Basin, an upper level ridge in the Midwest,=20
and a strong trough in the Northeast. At lower levels, weak high=20
pressure over the FL Straits and troughing in the western Gulf is=20
producing a lengthy moisture fetch with origins in the Caribbean=20
Sea. By 00Z Sat, ECMWF SATs shows a >90th climatological percentile
IVT oriented N-S and directed at the Southeast. This culminates in
a tropical air-mass sporting 2.0-2.2" PWs that is directed at a=20
stationary front in draped from the TN Valley to the SC coast.=20
Instability will be highest over AL on east into central and=20
southern GA with MUCAPE between 1,000-2,000 J/kg most often. MUCAPE
up to 1,000 J/kg will be available Friday night from the Savannah=20
River to coastal SC.=20

Area-averaged soundings show warm cloud layers as deep as 13,000ft
over eastern GA at the same time as a weak, yet negatively-tilted=20
250mb trough fosters synoptic-scale ascent aloft. Guidance shows
a cluster of heavy thunderstorms forming that will slowly make
their way east. The Slight Risk area resides just south of the
stalled front where greater instability will reside and atop some
of the more saturated soils in the region. The strongest storms
will have the capability to produce max rates up to 3"/hr rainfall
rates from eastern AL on east to the Savannah River Friday=20
afternoon and through Friday night. With increased confidence in=20
locally considerable rainfall rates over sensitive soils, a Slight
Risk was introduced.

Otherwise, some minor tweaks to the inherited Marginal Risk areas
were made in the Central Plains and Northern Rockies to account for
the latest WPC QPF.

Mullinax

---Previous Discussion---

...Eastern Washington to Northern Rockies...

A marginal risk is in place across far northeast Washington to
northwest Montana due to an increase in the heavy rainfall signal
for this period as the upper low over the West on Day 1, pivots
slightly northeastward, placing this region in an area with better
upper forcing and advection of moisture. The presence of anomalous
moisture and some instability may present a threat for localized
heavy rainfall and flash flooding, especially for burn scar
locations within this region.

...Middle Mississippi Valley to the Southeast...

Strong Canadian high pressure pressing in from the north will
allow for a slow moving cold front to press south over the course
of Thursday into Friday with convection likely to spawn along and
ahead of the front and dry air advecting behind the front leading
to a quick cutoff of activity. The front will arc back into the
Tennessee Valley to Middle Mississippi Valley, supported by the
persistent troughing over the south-central Plains. A moist and
unstable environment near and south of this front will support
scattered convection, with some heavier cells likely within the
pattern. It is still too hard to pick out any discernible areas of
interest, so maintained a very broad marginal risk over this area
which is quite wet and will continue to be in the Day 1 period.

Santorelli


Day 3
Valid 12Z Sat May 30 2026 - 12Z Sun May 31 2026

...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL ACROSS THE
NORTHERN ROCKIES TO HIGH PLAINS AND THE SOUTHEAST...

20Z Update...

There was consideration given to a Slight Risk over eastern GA on=20
east though much of coastal SC given the same setup supporting a=20
Slight Risk farther west on Friday should move east Saturday=20
morning. However, lingering model spread in both amounts and the=20
axis of heavier rainfall (as far north as northern SC, as far south
as the FL Panhandle) made it difficult to pinpoint a more "at-
risk" area. The coastal areas of the Southeast will be monitored=20
closely in the coming forecast cycles, but opted to maintain a=20
Marginal Risk given the lingering uncertainty. Meanwhile, in the=20
Northern Rockies, plenty of precipitation is likely coming to the=20
region on Saturday. The primary reason for no Slight Risk is due to
the potential for large sums of clouds possibly reducing the=20
instability available. This should be a beneficial soaking rain=20
event for drought-stricken central MT, but localized areas of flash
flooding are possible in poor drainage areas and along complex=20
terrain.

Mullinax

---Previous Discussion---

...Northern Rockies to High Plains...

The upper level low over the West during the Day 1 and 2 periods
will weaken and shift northeastward, moving over the Northern
Rockies to High Plains region on Day 3/Saturday. Moisture anomalies
will continue to be in the 90-90th percentile, supporting moderate
to heavy rainfall, with widespread QPF greater than 0.5-1" likely
across western and central Montana. There may not be a lot of
instability to work with, so any flood or flash flood threats
should be mainly localized with particular attention to burn scar
locations. A fairly broad marginal risk is in place across much of
western and central Montana, into parts of northern Wyoming as
well.

...Southeast...

Same story as Days 1 and 2, with ample moisture and instability
present near and south of a cold front that may stall over the
region on Saturday supporting convection, across much of the
Southeast. Some of this region, especially western parts of South
Carolina and into the Appalachians has been very wet as of late and
is well primed, so may be more favorable for flooding concerns.
The marginal risk though continues towards the coast due to the
presence of a weak frontal wave in the region. The Marginal Risk
extends from the Southeast coast, westward into northeast Alabama
and southeast Tennessee.

Santorelli


Day 1 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/94epoints.txt__;!!DZ3fjg!6MurZtKwKkG4-mKOaqnZctHaTF8ZbCkJsZS0M4cM25wo= Jo6kOtaYNRbYm4OQhQcWXT9xD83QqIUi4jCNpbklVRh7dTw$=20
Day 2 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/98epoints.txt__;!!DZ3fjg!6MurZtKwKkG4-mKOaqnZctHaTF8ZbCkJsZS0M4cM25wo= Jo6kOtaYNRbYm4OQhQcWXT9xD83QqIUi4jCNpbklANEudFM$=20
Day 3 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/99epoints.txt__;!!DZ3fjg!6MurZtKwKkG4-mKOaqnZctHaTF8ZbCkJsZS0M4cM25wo= Jo6kOtaYNRbYm4OQhQcWXT9xD83QqIUi4jCNpbkl2kVdMfo$=20

=3D =3D =3D
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--- SBBSecho 3.28-Linux
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FOUS30 KWBC 282140
QPFERD

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
540 PM EDT Thu May 28 2026

Day 1
Valid 2135Z Fri May 29 2026 - 12Z Fri May 29 2026

...THERE ARE SLIGHTS RISKS OF EXCESSIVE RAINFALL ALONG THE CENTRAL
GULF COAST, CENTRAL KANSAS, AND IN THE OZARKS OF MISSOURI AND
ARKANSAS...

21Z Update...

Slight Risk area over southeast LA and southern MS was removed=20
based on the latest observational/mesoanalysis and guidance trends.
Elsewhere, have expanded the Marginal Risk a little farther east of
the Cascades across central-eastern OR, also based on the latest=20 observational and forecast trends, as noted in Mesoscale=20
Precipitation Discussion (MPD) #268.

Hurley

...Central Gulf Coast...

The 12Z LIX sounding was effectively a tropical sounding with
plenty of MLCAPE present (>2,000 J/kg). Winds within the depth of
the cloud layer were almost uniformly out of the south with
training thunderstorms a concern from NOLA non north and east along
the I-59 corridor. Soils remain highly saturated and primed for
flash flooding with rainfall rates that could top 3"/hr in the
heaviest thunderstorm activity. Storms are at least moving along at
a steady clip, which should help to reduce the areal extent for
flash flooding. That said, these storms may exacerbate the flooding
the region has experienced in recent days. For these reasons, a
Slight Risk was introduced.

...Ozarks & Central Arkansas...

A narrow NW-SE corridor of anomalous PWs (>2.0" PWs that top the
99.5 climatological percentile per ECMWF) is caught between a
strong ridge of high pressure in the Upper MS Valley and a
negatively tilted 850-300mb trough oriented from southern KS to the
ArkLaTex. Strong vertical ascent ahead of the 850-300mb trough
axis coupled with MLCAPE between 500-1,000 J/kg will give more
support to these highly saturated profiles. Area-averaged
soundings over northern AR show >85% RH values between 1000-500mb
and warm cloud layers >13,000ft this afternoon and evening. Soils
are most sensitive in central AR, while the Ozarks are historically
a "flashy" area that, even with some drier soil moisture values in
southern MO are prone to flash flooding given rainfall rates could
surpass 2"/hr. The 12Z HREF does show high chance probabilities

70%) for rainfall amounts >3" in southwest MO and northern AR,

with low chance probabilities (20-35%) for >5" amounts. In
collaboration with WFOs in northern AR and southern MO, opted to
upgrade to a Slight Risk for the 16Z update.

...Central KS...

A pivoting 700mb low rotating through southern KS will direct a
plume of highly anomalous moisture for late May/early June over the
heart of KS. Per RAP mesoanalysis, PWs are already >1.5" and could
surpass 1.75" this afternoon. Central KS is ideally placed just
ahead of a negatively tilted 850-300mb trough that is generating
excellent upper-level divergence. Additional storms will form this
afternoon with HRRR area-averaged soundings showing >500 J/kg of
MLCAPE, >85% RH values within the mean 1000-500mb layer, and warm
cloud layers up to 12,000ft deep. Wind more uniformly out of the SE
are also supporting the potential for training storms, evident
from upshear corfidi vectors that are as low as 10 kts. New 12Z
HREF probabilities show high chance (>70%) for rainfall totals >3"
from Wichita on north and west with low-to-moderate chances
(20-40%) for localized amounts >5". Soils in the area are parched,
but these kind of rates can still support flash flooding,
particularly where repeating rounds of storms occur and in more
urbanized settings. In collaboration with ICT, decided to upgrade
to a Slight Risk for the 16Z update.

Mullinax

---Previous Discussion---

...Florida...

An active sea breeze pattern with weakening steering flow will
lead to periods of heavy rainfall across southeast Florida this
afternoon. Greatest concern remains over the South Florida metro
corridor from West Palm Beach to Miami. Latest HREF is robust with
showing greater than 50% probabilities for 3" in 24-hours, with
even some modest, albeit localized, probabilities for 5". This
correlates well with CAM guidance, with some indicating bullseyes
of greater than 3" within the larger QPF footprint. Locally
significant rainfall is likely in this relatively classic pattern
with ample moisture and instability present. A marginal risk
remains in effect across Southeast Florida.

...Washington/Oregon...

A deep upper level low over the West will allow for a broad axis
of diffluent flow across the interior Northwest. Precipitable water
values 1-1.5" are in the 90-90th percentile, and with sufficient
instability, should support convection capable of producing heavy
rainfall. Flooding and flash flooding are a concern for mainly the
more vulnerable areas - urban, small stream, and low lying areas.
HREF 24-hr probabilities for greater than 3" are between 40-70% for
especially the Oregon cascades. Given the favorable environment
though, a marginal risk extends all the way from far northern
California northward to the eastern half of Washington state. A
previous marginal risk for parts of the northern Rockies was
trimmed out for this update given the lack of QPF signal.

Santorelli


Day 2
Valid 12Z Fri May 29 2026 - 12Z Sat May 30 2026

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL ACROSS PORTIONS OF
THE SOUTHEAST...

20Z Update...

In collaboration with several Southeast WFOs, a Slight Risk was
introduced from eastern AL to the GA/SC border. The region is
caught out ahead of a sheared 500mb vorticity maximum approaching
from the west. This feature is caught between a closed low
traversing the Great Basin, an upper level ridge in the Midwest,
and a strong trough in the Northeast. At lower levels, weak high
pressure over the FL Straits and troughing in the western Gulf is
producing a lengthy moisture fetch with origins in the Caribbean
Sea. By 00Z Sat, ECMWF SATs shows a >90th climatological percentile
IVT oriented N-S and directed at the Southeast. This culminates in
a tropical air-mass sporting 2.0-2.2" PWs that is directed at a
stationary front in draped from the TN Valley to the SC coast.
Instability will be highest over AL on east into central and
southern GA with MUCAPE between 1,000-2,000 J/kg most often. MUCAPE
up to 1,000 J/kg will be available Friday night from the Savannah
River to coastal SC.

Area-averaged soundings show warm cloud layers as deep as 13,000ft
over eastern GA at the same time as a weak, yet negatively-tilted
250mb trough fosters synoptic-scale ascent aloft. Guidance shows
a cluster of heavy thunderstorms forming that will slowly make
their way east. The Slight Risk area resides just south of the
stalled front where greater instability will reside and atop some
of the more saturated soils in the region. The strongest storms
will have the capability to produce max rates up to 3"/hr rainfall
rates from eastern AL on east to the Savannah River Friday
afternoon and through Friday night. With increased confidence in
locally considerable rainfall rates over sensitive soils, a Slight
Risk was introduced.

Otherwise, some minor tweaks to the inherited Marginal Risk areas
were made in the Central Plains and Northern Rockies to account for
the latest WPC QPF.

Mullinax

---Previous Discussion---

...Eastern Washington to Northern Rockies...

A marginal risk is in place across far northeast Washington to
northwest Montana due to an increase in the heavy rainfall signal
for this period as the upper low over the West on Day 1, pivots
slightly northeastward, placing this region in an area with better
upper forcing and advection of moisture. The presence of anomalous
moisture and some instability may present a threat for localized
heavy rainfall and flash flooding, especially for burn scar
locations within this region.

...Middle Mississippi Valley to the Southeast...

Strong Canadian high pressure pressing in from the north will
allow for a slow moving cold front to press south over the course
of Thursday into Friday with convection likely to spawn along and
ahead of the front and dry air advecting behind the front leading
to a quick cutoff of activity. The front will arc back into the
Tennessee Valley to Middle Mississippi Valley, supported by the
persistent troughing over the south-central Plains. A moist and
unstable environment near and south of this front will support
scattered convection, with some heavier cells likely within the
pattern. It is still too hard to pick out any discernible areas of
interest, so maintained a very broad marginal risk over this area
which is quite wet and will continue to be in the Day 1 period.

Santorelli


Day 3
Valid 12Z Sat May 30 2026 - 12Z Sun May 31 2026

...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL ACROSS THE
NORTHERN ROCKIES TO HIGH PLAINS AND THE SOUTHEAST...

20Z Update...

There was consideration given to a Slight Risk over eastern GA on
east though much of coastal SC given the same setup supporting a
Slight Risk farther west on Friday should move east Saturday
morning. However, lingering model spread in both amounts and the
axis of heavier rainfall (as far north as northern SC, as far south
as the FL Panhandle) made it difficult to pinpoint a more "at-
risk" area. The coastal areas of the Southeast will be monitored
closely in the coming forecast cycles, but opted to maintain a
Marginal Risk given the lingering uncertainty. Meanwhile, in the
Northern Rockies, plenty of precipitation is likely coming to the
region on Saturday. The primary reason for no Slight Risk is due to
the potential for large sums of clouds possibly reducing the
instability available. This should be a beneficial soaking rain
event for drought-stricken central MT, but localized areas of flash
flooding are possible in poor drainage areas and along complex
terrain.

Mullinax

---Previous Discussion---

...Northern Rockies to High Plains...

The upper level low over the West during the Day 1 and 2 periods
will weaken and shift northeastward, moving over the Northern
Rockies to High Plains region on Day 3/Saturday. Moisture anomalies
will continue to be in the 90-90th percentile, supporting moderate
to heavy rainfall, with widespread QPF greater than 0.5-1" likely
across western and central Montana. There may not be a lot of
instability to work with, so any flood or flash flood threats
should be mainly localized with particular attention to burn scar
locations. A fairly broad marginal risk is in place across much of
western and central Montana, into parts of northern Wyoming as
well.

...Southeast...

Same story as Days 1 and 2, with ample moisture and instability
present near and south of a cold front that may stall over the
region on Saturday supporting convection, across much of the
Southeast. Some of this region, especially western parts of South
Carolina and into the Appalachians has been very wet as of late and
is well primed, so may be more favorable for flooding concerns.
The marginal risk though continues towards the coast due to the
presence of a weak frontal wave in the region. The Marginal Risk
extends from the Southeast coast, westward into northeast Alabama
and southeast Tennessee.

Santorelli


Day 1 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/94epoints.txt__;!!DZ3fjg!8d3O9omLKAbtvgtNTk6Uhheml2ux8RrWX3zmMaIA7s0i= NFp5SUmEmkZU7jgkQID15EEsbBp-K3CXliA1vpRMFgsd-Y0$=20
Day 2 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/98epoints.txt__;!!DZ3fjg!8d3O9omLKAbtvgtNTk6Uhheml2ux8RrWX3zmMaIA7s0i= NFp5SUmEmkZU7jgkQID15EEsbBp-K3CXliA1vpRMO2TWeGQ$=20
Day 3 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/99epoints.txt__;!!DZ3fjg!8d3O9omLKAbtvgtNTk6Uhheml2ux8RrWX3zmMaIA7s0i= NFp5SUmEmkZU7jgkQID15EEsbBp-K3CXliA1vpRM0LlNj7s$=20

=3D =3D =3D
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FOUS30 KWBC 290056
QPFERD

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
856 PM EDT Thu May 28 2026

Day 1
Valid 01Z Fri May 29 2026 - 12Z Fri May 29 2026

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL ACROSS PARTS OF THE
MID-SOUTH AND OZARKS...

01Z Update...

Have dropped the Marginal Risk across much of the Southeast
(outside of SE FL), given the lack of deep layer forcing, decaying
diurnal heating and sea breezes, and weak mid level lapse rates.
Despite better forcing (along mid level deformation axis/TROWAL
zone), diminishing deep-layer instability has also allowed for the
Slight Risk over KS to drop to a Marginal. Otherwise, the Slight
over central-northern AR into southwest and south-central MO
continues, based on the latest observational trends (radar,
satellite, mesoanalysis), along with recent HRRR trends and
elevated QPF exceedance probabilities from the 18Z HREF.=20

Have also expanded the Marginal Risk over the northern Rockies and Intermountain West areas, based largely on current observational
trends.=20

Hurley

---Previous Discussion---

...Florida...

An active sea breeze pattern with weakening steering flow will
lead to periods of heavy rainfall across southeast Florida this
afternoon. Greatest concern remains over the South Florida metro
corridor from West Palm Beach to Miami. Latest HREF is robust with
showing greater than 50% probabilities for 3" in 24-hours, with
even some modest, albeit localized, probabilities for 5". This
correlates well with CAM guidance, with some indicating bullseyes
of greater than 3" within the larger QPF footprint. Locally
significant rainfall is likely in this relatively classic pattern
with ample moisture and instability present. A marginal risk
remains in effect across Southeast Florida.

...Washington/Oregon...

A deep upper level low over the West will allow for a broad axis
of diffluent flow across the interior Northwest. Precipitable water
values 1-1.5" are in the 90-90th percentile, and with sufficient
instability, should support convection capable of producing heavy
rainfall. Flooding and flash flooding are a concern for mainly the
more vulnerable areas - urban, small stream, and low lying areas.
HREF 24-hr probabilities for greater than 3" are between 40-70% for
especially the Oregon cascades. Given the favorable environment
though, a marginal risk extends all the way from far northern
California northward to the eastern half of Washington state. A
previous marginal risk for parts of the northern Rockies was
trimmed out for this update given the lack of QPF signal.

Santorelli


Day 2
Valid 12Z Fri May 29 2026 - 12Z Sat May 30 2026

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL ACROSS PORTIONS OF
THE SOUTHEAST...

20Z Update...

In collaboration with several Southeast WFOs, a Slight Risk was
introduced from eastern AL to the GA/SC border. The region is
caught out ahead of a sheared 500mb vorticity maximum approaching
from the west. This feature is caught between a closed low
traversing the Great Basin, an upper level ridge in the Midwest,
and a strong trough in the Northeast. At lower levels, weak high
pressure over the FL Straits and troughing in the western Gulf is
producing a lengthy moisture fetch with origins in the Caribbean
Sea. By 00Z Sat, ECMWF SATs shows a >90th climatological percentile
IVT oriented N-S and directed at the Southeast. This culminates in
a tropical air-mass sporting 2.0-2.2" PWs that is directed at a
stationary front in draped from the TN Valley to the SC coast.
Instability will be highest over AL on east into central and
southern GA with MUCAPE between 1,000-2,000 J/kg most often. MUCAPE
up to 1,000 J/kg will be available Friday night from the Savannah
River to coastal SC.

Area-averaged soundings show warm cloud layers as deep as 13,000ft
over eastern GA at the same time as a weak, yet negatively-tilted
250mb trough fosters synoptic-scale ascent aloft. Guidance shows
a cluster of heavy thunderstorms forming that will slowly make
their way east. The Slight Risk area resides just south of the
stalled front where greater instability will reside and atop some
of the more saturated soils in the region. The strongest storms
will have the capability to produce max rates up to 3"/hr rainfall
rates from eastern AL on east to the Savannah River Friday
afternoon and through Friday night. With increased confidence in
locally considerable rainfall rates over sensitive soils, a Slight
Risk was introduced.

Otherwise, some minor tweaks to the inherited Marginal Risk areas
were made in the Central Plains and Northern Rockies to account for
the latest WPC QPF.

Mullinax

---Previous Discussion---

...Eastern Washington to Northern Rockies...

A marginal risk is in place across far northeast Washington to
northwest Montana due to an increase in the heavy rainfall signal
for this period as the upper low over the West on Day 1, pivots
slightly northeastward, placing this region in an area with better
upper forcing and advection of moisture. The presence of anomalous
moisture and some instability may present a threat for localized
heavy rainfall and flash flooding, especially for burn scar
locations within this region.

...Middle Mississippi Valley to the Southeast...

Strong Canadian high pressure pressing in from the north will
allow for a slow moving cold front to press south over the course
of Thursday into Friday with convection likely to spawn along and
ahead of the front and dry air advecting behind the front leading
to a quick cutoff of activity. The front will arc back into the
Tennessee Valley to Middle Mississippi Valley, supported by the
persistent troughing over the south-central Plains. A moist and
unstable environment near and south of this front will support
scattered convection, with some heavier cells likely within the
pattern. It is still too hard to pick out any discernible areas of
interest, so maintained a very broad marginal risk over this area
which is quite wet and will continue to be in the Day 1 period.

Santorelli


Day 3
Valid 12Z Sat May 30 2026 - 12Z Sun May 31 2026

...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL ACROSS THE
NORTHERN ROCKIES TO HIGH PLAINS AND THE SOUTHEAST...

20Z Update...

There was consideration given to a Slight Risk over eastern GA on
east though much of coastal SC given the same setup supporting a
Slight Risk farther west on Friday should move east Saturday
morning. However, lingering model spread in both amounts and the
axis of heavier rainfall (as far north as northern SC, as far south
as the FL Panhandle) made it difficult to pinpoint a more "at-
risk" area. The coastal areas of the Southeast will be monitored
closely in the coming forecast cycles, but opted to maintain a
Marginal Risk given the lingering uncertainty. Meanwhile, in the
Northern Rockies, plenty of precipitation is likely coming to the
region on Saturday. The primary reason for no Slight Risk is due to
the potential for large sums of clouds possibly reducing the
instability available. This should be a beneficial soaking rain
event for drought-stricken central MT, but localized areas of flash
flooding are possible in poor drainage areas and along complex
terrain.

Mullinax

---Previous Discussion---

...Northern Rockies to High Plains...

The upper level low over the West during the Day 1 and 2 periods
will weaken and shift northeastward, moving over the Northern
Rockies to High Plains region on Day 3/Saturday. Moisture anomalies
will continue to be in the 90-90th percentile, supporting moderate
to heavy rainfall, with widespread QPF greater than 0.5-1" likely
across western and central Montana. There may not be a lot of
instability to work with, so any flood or flash flood threats
should be mainly localized with particular attention to burn scar
locations. A fairly broad marginal risk is in place across much of
western and central Montana, into parts of northern Wyoming as
well.

...Southeast...

Same story as Days 1 and 2, with ample moisture and instability
present near and south of a cold front that may stall over the
region on Saturday supporting convection, across much of the
Southeast. Some of this region, especially western parts of South
Carolina and into the Appalachians has been very wet as of late and
is well primed, so may be more favorable for flooding concerns.
The marginal risk though continues towards the coast due to the
presence of a weak frontal wave in the region. The Marginal Risk
extends from the Southeast coast, westward into northeast Alabama
and southeast Tennessee.

Santorelli


Day 1 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/94epoints.txt__;!!DZ3fjg!902C38snp3pXPRtfz4A7rnbHIikqtOm0XpqTP14K8Nsg= Bnuw6ZPa_lURLpQ-OZwotaY6YscB2EwW1OAb1kCjLiu7AOE$=20
Day 2 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/98epoints.txt__;!!DZ3fjg!902C38snp3pXPRtfz4A7rnbHIikqtOm0XpqTP14K8Nsg= Bnuw6ZPa_lURLpQ-OZwotaY6YscB2EwW1OAb1kCj0sgGPBE$=20
Day 3 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/99epoints.txt__;!!DZ3fjg!902C38snp3pXPRtfz4A7rnbHIikqtOm0XpqTP14K8Nsg= Bnuw6ZPa_lURLpQ-OZwotaY6YscB2EwW1OAb1kCjzdjNcCU$=20

=3D =3D =3D
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FOUS30 KWBC 290829
QPFERD

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
429 AM EDT Fri May 29 2026

Day 1
Valid 12Z Fri May 29 2026 - 12Z Sat May 30 2026

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL ACROSS PORTIONS OF
THE SOUTHEAST...

Largely maintained the previous Slight Risk area that was introduced
in the Southeast US. A sheared 500mb vorticity maximum approaching
from the west will be encountering a moist airmass with increasing
amount of instability later during the day and evening. The latest
numerical guidance kept expected precipitable water values in the=20
2 to 2.25 inch range along and south of a quasi-stationary front=20
draped across the region from the TN Valley to the SC coast.=20
Instability will be highest over AL on east into central and=20
southern GA with MUCAPE between 1,000-2,000 J/kg most often. MUCAPE
up to 1,000 J/kg will be available later tonight from the Savannah
River to coastal SC. This combination should be enough to support=20
and sustain localized rainfall rates in excess of 2 inches per hour
where warm rain processes predominate from eastern AL eastward to=20
the Savannah River this afternoon and tonight.

...Middle Mississippi Valley to the Southeast...

The western portion of the front affecting the Southeast US will
extend into portions of the Middle Mississippi Valley and provide
the focus for showers and thunderstorms...some of which may produce
locally heavy rainfall from the Tennessee Valley into the Middle
Mississippi Valley into tonight.

...Eastern Washington to Northern Rockies...

A marginal risk remained in place across far northeast Washington=20
to northwest Montana due to an increase in the heavy rainfall=20
signal for this period as an upper low over the West on Day 1
places this region in an area with better upper forcing and=20
advection of moisture. The presence of anomalous moisture and some=20 instability may present a threat for localized heavy rainfall and=20
flash flooding, especially for burn scar locations within this=20
region.

Bann

Day 2
Valid 12Z Sat May 30 2026 - 12Z Sun May 31 2026

...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL ACROSS THE=20
NORTHERN ROCKIES TO HIGH PLAINS AND THE SOUTHEAST...

...Southeast...

Latest numerical guidance has shifted a majority of the rainfall
eastward enough compared with previous runs to preclude an upgrade
to a Slight risk. In addition...the spread of model=20
guidance both in terms of placement and amounts precluded an
upgrade. As mentioned previously...some of the region, especially=20
western parts of South Carolina and into the Appalachians, has=20
been very wet as of late and is well primed, so may by more
vulnerable to flooding concerns.

...Northern Rockies to High Plains...

The upper level low over the West during the Day 1 period will=20
weaken and shift northeastward, moving over the Northern Rockies to
High Plains region on Saturday. Moisture anomalies will continue=20
to be in the 90-90th percentile, supporting moderate to heavy=20
rainfall, with widespread QPF greater than 0.5-1" likely across=20
western and central Montana. There may not be a lot of instability=20
to work with, so any flood or flash flood threats should be mainly=20
localized with particular attention to burn scar locations. A=20
fairly broad marginal risk remained in place across much of=20
western and central Montana, into parts of northern Wyoming as=20
well.

Bann

Day 3
Valid 12Z Sun May 31 2026 - 12Z Mon Jun 01 2026

...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL OVER PORTIONS OF
THE NORTHERN ROCKIES AND THE SOUTHEAST UNITED STATES...

...Northern Rockies and Adjacent High Plains...
The upper level low which has been supporting the prolonged wet
period over the Northern Rockies will continue to move northward=20
across Montana slowly on Sunday. This results in surface low=20
pressure and associated surface front to makes its way out over the
Plains and gradually weaken while the mid and upper level=20
circulation keeps precipitation lingering over Montana and far=20
northern Wyoming. Moisture remains anomalously high but instability
still looks to be dependent upon cloud cover. As in the Day 2=20
period...any flood or flash flood threats should be mainly=20
localized with particular attention to burn scar locations.=20

...Southeast...
Until surface high pressure builds far enough southward into the
Southeast states to decrease coverage of lingering convection on
Sunday evening...the antecedent conditions keep a risk of flooding
concerns over the area.=20=20

Bann


Day 1 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/94epoints.txt__;!!DZ3fjg!43Ee_BhAegIoLhjRiEH4J7W9ckg7tNRpnR0rt_Vdjcnc= zWZ8gKRiuMLnnxaWkhAQhBOooFBAuVjkJ0OdEEQyjfXv58k$=20
Day 2 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/98epoints.txt__;!!DZ3fjg!43Ee_BhAegIoLhjRiEH4J7W9ckg7tNRpnR0rt_Vdjcnc= zWZ8gKRiuMLnnxaWkhAQhBOooFBAuVjkJ0OdEEQygPehz1c$=20
Day 3 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/99epoints.txt__;!!DZ3fjg!43Ee_BhAegIoLhjRiEH4J7W9ckg7tNRpnR0rt_Vdjcnc= zWZ8gKRiuMLnnxaWkhAQhBOooFBAuVjkJ0OdEEQy2RqMZEY$=20

=3D =3D =3D
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FOUS30 KWBC 291558
QPFERD

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
1158 AM EDT Fri May 29 2026

Day 1
Valid 16Z Fri May 29 2026 - 12Z Sat May 30 2026

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL ACROSS PORTIONS OF
THE SOUTHEAST AND TENNESSEE VALLEY...

16z Update: Main change is an expansion of the Slight risk across=20
TN, far southern KY, northern AR and southern MO. Overall would=20
generally consider the flash flood risk isolated, but a few=20
clusters of more concentrated impacts appear probable. FFG=20
exceedance probabilities from both the 12z HREF and REFS show a=20
broad corridor of 15-30% values approximately aligned with the=20
adjusted Slight risk area, with 3" neighborhood exceedance=20
probabilities of ~40-70%. So while coverage of these higher amounts
should stay localized, weak flow and broad lower level convergence
will support a few convective clusters capable of 2" per hour=20
rainfall and totals exceeding 3".

Made some tweaks to confine the Marginal risk over New England to=20
just NH into western Maine. A widespread 1-2" of rain is expected=20
as a strong mid/upper low dives southeast into the region, with=20
both the HREF and REFS supporting localized totals over 3". Hourly=20
rainfall rates will generally stay below 1", however could locally=20
exceed 1" as the low drops south tonight and we get some enhanced=20 convergence closer to the NH and ME coasts. A few spots could see=20
event total rainfall around or just above 3", which combined with=20
1" per hour rates, could be enough to result in localized flash=20
flood impacts.

A Small Marginal risk was added for dryline convection across west
TX. Storm motions should be quick enough to limit the risk,=20
however, a few supercells could briefly anchor to the dryline and=20
locally enhance rainfall totals.

Chenard

...Previous Discussion...

Largely maintained the previous Slight Risk area that was introduced
in the Southeast US. A sheared 500mb vorticity maximum approaching
from the west will be encountering a moist airmass with increasing
amount of instability later during the day and evening. The latest
numerical guidance kept expected precipitable water values in the
2 to 2.25 inch range along and south of a quasi-stationary front
draped across the region from the TN Valley to the SC coast.
Instability will be highest over AL on east into central and
southern GA with MUCAPE between 1,000-2,000 J/kg most often. MUCAPE
up to 1,000 J/kg will be available later tonight from the Savannah
River to coastal SC. This combination should be enough to support
and sustain localized rainfall rates in excess of 2 inches per hour
where warm rain processes predominate from eastern AL eastward to
the Savannah River this afternoon and tonight.

...Middle Mississippi Valley to the Southeast...

The western portion of the front affecting the Southeast US will
extend into portions of the Middle Mississippi Valley and provide
the focus for showers and thunderstorms...some of which may produce
locally heavy rainfall from the Tennessee Valley into the Middle
Mississippi Valley into tonight.

...Eastern Washington to Northern Rockies...

A marginal risk remained in place across far northeast Washington
to northwest Montana due to an increase in the heavy rainfall
signal for this period as an upper low over the West on Day 1
places this region in an area with better upper forcing and
advection of moisture. The presence of anomalous moisture and some
instability may present a threat for localized heavy rainfall and
flash flooding, especially for burn scar locations within this
region.

Bann

Day 2
Valid 12Z Sat May 30 2026 - 12Z Sun May 31 2026

...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL ACROSS THE
NORTHERN ROCKIES TO HIGH PLAINS AND THE SOUTHEAST...

...Southeast...

Latest numerical guidance has shifted a majority of the rainfall
eastward enough compared with previous runs to preclude an upgrade
to a Slight risk. In addition...the spread of model
guidance both in terms of placement and amounts precluded an
upgrade. As mentioned previously...some of the region, especially
western parts of South Carolina and into the Appalachians, has
been very wet as of late and is well primed, so may by more
vulnerable to flooding concerns.

...Northern Rockies to High Plains...

The upper level low over the West during the Day 1 period will
weaken and shift northeastward, moving over the Northern Rockies to
High Plains region on Saturday. Moisture anomalies will continue
to be in the 90-90th percentile, supporting moderate to heavy
rainfall, with widespread QPF greater than 0.5-1" likely across
western and central Montana. There may not be a lot of instability
to work with, so any flood or flash flood threats should be mainly
localized with particular attention to burn scar locations. A
fairly broad marginal risk remained in place across much of
western and central Montana, into parts of northern Wyoming as
well.

Bann

Day 3
Valid 12Z Sun May 31 2026 - 12Z Mon Jun 01 2026

...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL OVER PORTIONS OF
THE NORTHERN ROCKIES AND THE SOUTHEAST UNITED STATES...

...Northern Rockies and Adjacent High Plains...
The upper level low which has been supporting the prolonged wet
period over the Northern Rockies will continue to move northward
across Montana slowly on Sunday. This results in surface low
pressure and associated surface front to makes its way out over the
Plains and gradually weaken while the mid and upper level
circulation keeps precipitation lingering over Montana and far
northern Wyoming. Moisture remains anomalously high but instability
still looks to be dependent upon cloud cover. As in the Day 2
period...any flood or flash flood threats should be mainly
localized with particular attention to burn scar locations.

...Southeast...
Until surface high pressure builds far enough southward into the
Southeast states to decrease coverage of lingering convection on
Sunday evening...the antecedent conditions keep a risk of flooding
concerns over the area.

Bann


Day 1 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/94epoints.txt__;!!DZ3fjg!6tDTSy2GuRSwMzlbmb9eX0AALj8Qvra6J170FFwY7PLx= dHV8eCYBFUMuTbMasaV4UAfdQVVBNYBd58PH0rzBdQrW9-s$=20
Day 2 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/98epoints.txt__;!!DZ3fjg!6tDTSy2GuRSwMzlbmb9eX0AALj8Qvra6J170FFwY7PLx= dHV8eCYBFUMuTbMasaV4UAfdQVVBNYBd58PH0rzBJGiZY-Y$=20
Day 3 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/99epoints.txt__;!!DZ3fjg!6tDTSy2GuRSwMzlbmb9eX0AALj8Qvra6J170FFwY7PLx= dHV8eCYBFUMuTbMasaV4UAfdQVVBNYBd58PH0rzBDFcy11k$=20

=3D =3D =3D
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FOUS30 KWBC 292008
QPFERD

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
408 PM EDT Fri May 29 2026

Day 1
Valid 16Z Fri May 29 2026 - 12Z Sat May 30 2026

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL ACROSS PORTIONS OF
THE SOUTHEAST AND TENNESSEE VALLEY...

16z Update: Main change is an expansion of the Slight risk across
TN, far southern KY, northern AR and southern MO. Overall would
generally consider the flash flood risk isolated, but a few
clusters of more concentrated impacts appear probable. FFG
exceedance probabilities from both the 12z HREF and REFS show a
broad corridor of 15-30% values approximately aligned with the
adjusted Slight risk area, with 3" neighborhood exceedance
probabilities of ~40-70%. So while coverage of these higher amounts
should stay localized, weak flow and broad lower level convergence
will support a few convective clusters capable of 2" per hour
rainfall and totals exceeding 3".

Made some tweaks to confine the Marginal risk over New England to
just NH into western Maine. A widespread 1-2" of rain is expected
as a strong mid/upper low dives southeast into the region, with
both the HREF and REFS supporting localized totals over 3". Hourly
rainfall rates will generally stay below 1", however could locally
exceed 1" as the low drops south tonight and we get some enhanced
convergence closer to the NH and ME coasts. A few spots could see
event total rainfall around or just above 3", which combined with
1" per hour rates, could be enough to result in localized flash
flood impacts.

A Small Marginal risk was added for dryline convection across west
TX. Storm motions should be quick enough to limit the risk,
however, a few supercells could briefly anchor to the dryline and
locally enhance rainfall totals.

Chenard

...Previous Discussion...

Largely maintained the previous Slight Risk area that was introduced
in the Southeast US. A sheared 500mb vorticity maximum approaching
from the west will be encountering a moist airmass with increasing
amount of instability later during the day and evening. The latest
numerical guidance kept expected precipitable water values in the
2 to 2.25 inch range along and south of a quasi-stationary front
draped across the region from the TN Valley to the SC coast.
Instability will be highest over AL on east into central and
southern GA with MUCAPE between 1,000-2,000 J/kg most often. MUCAPE
up to 1,000 J/kg will be available later tonight from the Savannah
River to coastal SC. This combination should be enough to support
and sustain localized rainfall rates in excess of 2 inches per hour
where warm rain processes predominate from eastern AL eastward to
the Savannah River this afternoon and tonight.

...Middle Mississippi Valley to the Southeast...

The western portion of the front affecting the Southeast US will
extend into portions of the Middle Mississippi Valley and provide
the focus for showers and thunderstorms...some of which may produce
locally heavy rainfall from the Tennessee Valley into the Middle
Mississippi Valley into tonight.

...Eastern Washington to Northern Rockies...

A marginal risk remained in place across far northeast Washington
to northwest Montana due to an increase in the heavy rainfall
signal for this period as an upper low over the West on Day 1
places this region in an area with better upper forcing and
advection of moisture. The presence of anomalous moisture and some
instability may present a threat for localized heavy rainfall and
flash flooding, especially for burn scar locations within this
region.

Bann

Day 2
Valid 12Z Sat May 30 2026 - 12Z Sun May 31 2026

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL ACROSS PORTIONS OF
MONTANA...

20z Update: Upgraded to a Slight risk across portions of MT where=20
isolated to scattered flash flooding is possible. The eastern half
of the Slight risk area should see the highest rainfall rates,=20
with HREF neighborhood probabilities of exceeding 1"/hr in the=20
30-50% range, and 2"/hr around 10%. This results in HREF FFG=20
exceedance probabilities broadly over 25%. There should be enough=20
coverage of higher rainfall rates to result in some flash flood=20
risk. Instability is less the farther west you go in MT, but=20
rainfall coverage will be greater, resulting in higher areal=20
averaged rainfall. The flood risk should gradually transition from
flash flood to areal flood/river flood as you go west across the=20
state.

Elsewhere, the Marginal risk was broadened across the Northern
Plains into the MS Valley along an elongated moisture axis.
Convective details are uncertain at this lead time, but that=20
entire corridor will have above average moisture and some=20
forcing.The most organized convective threat may end up over=20
portions of NE and SD Saturday night as stronger forcing ejects=20
into the area. However, there are also signals of organized=20
convective clusters within the moisture axis anywhere from AR to=20
IA. While convection is unlikely along this entire axis...where it
does develop rainfall rate potential will be high enough for=20
localized flash flooding.

Chenard

...Previous Discussion...

...Southeast...

Latest numerical guidance has shifted a majority of the rainfall
eastward enough compared with previous runs to preclude an upgrade
to a Slight risk. In addition...the spread of model
guidance both in terms of placement and amounts precluded an
upgrade. As mentioned previously...some of the region, especially
western parts of South Carolina and into the Appalachians, has
been very wet as of late and is well primed, so may by more
vulnerable to flooding concerns.

...Northern Rockies to High Plains...

The upper level low over the West during the Day 1 period will
weaken and shift northeastward, moving over the Northern Rockies to
High Plains region on Saturday. Moisture anomalies will continue
to be in the 90-90th percentile, supporting moderate to heavy
rainfall, with widespread QPF greater than 0.5-1" likely across
western and central Montana. There may not be a lot of instability
to work with, so any flood or flash flood threats should be mainly
localized with particular attention to burn scar locations. A
fairly broad marginal risk remained in place across much of
western and central Montana, into parts of northern Wyoming as
well.

Bann

Day 3
Valid 12Z Sun May 31 2026 - 12Z Mon Jun 01 2026

...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL STRETCHING FROM
MONTANA TO NORTHERN FLORIDA...

20Z Update: Expanded the Marginal risk to cover most of the
anomalous moisture plume that will extend from MT into the=20
Southeast U.S. in between troughing over the West and Northeast.=20
Large scale forcing is more subtle outside of the Northern=20 Plains/Rockies...but there should be some weak shortwaves=20
embedded within the weak flow. Global deterministic models,=20
ensemble means and AI models show a broad convective threat along=20
this entire corridor, with no clear area of higher focus. Thus at=20
the moment a large Marginal seems to handle the localized flash=20
flood risk that should exist. Some fine tuning of the Marginal=20
and/or focused Slight risk upgrades will be possible as we get=20
closer and convective mode/evolution becomes clearer.

Chenard

...Previous Discussion...

...Northern Rockies and Adjacent High Plains...
The upper level low which has been supporting the prolonged wet
period over the Northern Rockies will continue to move northward
across Montana slowly on Sunday. This results in surface low
pressure and associated surface front to makes its way out over the
Plains and gradually weaken while the mid and upper level
circulation keeps precipitation lingering over Montana and far
northern Wyoming. Moisture remains anomalously high but instability
still looks to be dependent upon cloud cover. As in the Day 2
period...any flood or flash flood threats should be mainly
localized with particular attention to burn scar locations.

...Southeast...
Until surface high pressure builds far enough southward into the
Southeast states to decrease coverage of lingering convection on
Sunday evening...the antecedent conditions keep a risk of flooding
concerns over the area.

Bann


Day 1 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/94epoints.txt__;!!DZ3fjg!7q9UGCqtgog0Bl9yr0qtN1mXWiwnPCr5fHYjbfw-Cr5r= TuEBoNKevXGcaHyWgXzN_4fOwpnpXJyu4QWBZxRmBQxj8vo$=20
Day 2 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/98epoints.txt__;!!DZ3fjg!7q9UGCqtgog0Bl9yr0qtN1mXWiwnPCr5fHYjbfw-Cr5r= TuEBoNKevXGcaHyWgXzN_4fOwpnpXJyu4QWBZxRmbfh3WaE$=20
Day 3 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/99epoints.txt__;!!DZ3fjg!7q9UGCqtgog0Bl9yr0qtN1mXWiwnPCr5fHYjbfw-Cr5r= TuEBoNKevXGcaHyWgXzN_4fOwpnpXJyu4QWBZxRmHsc1SjQ$=20

=3D =3D =3D
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FOUS30 KWBC 300048
QPFERD

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
848 PM EDT Fri May 29 2026

Day 1
Valid 01Z Sat May 30 2026 - 12Z Sat May 30 2026

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL ACROSS PORTIONS OF
THE SOUTHEAST AND TENNESSEE VALLEY...

01Z Update: As has been the case, late-period changes to the Day 1
ERO were primarily to remove areas from the Slight and Marginal
Risk area that have been worked over and/or have seen a diminished
threat given the loss of diurnal heating. Observational trends
along with the elevated 18Z HREF neighborhood probabilities of 3+=20
inches of additional rainfall through 12Z have resulted in a
continuation of the Slight Risk across much of GA into eastern AL
and eastern TN. Still sufficient deep-layer instability over these
areas to pose a more heightened risk of excessive rainfall, with
mixed-layer CAPEs between 1000-2000 J/Kg. Peak neighborhood
probabilities of >3" through 12Z per the 18Z HREF are between
40-60% in this region.=20

Hurley


Day 2
Valid 12Z Sat May 30 2026 - 12Z Sun May 31 2026

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL ACROSS PORTIONS OF
MONTANA...

20z Update: Upgraded to a Slight risk across portions of MT where
isolated to scattered flash flooding is possible. The eastern half
of the Slight risk area should see the highest rainfall rates,
with HREF neighborhood probabilities of exceeding 1"/hr in the
30-50% range, and 2"/hr around 10%. This results in HREF FFG
exceedance probabilities broadly over 25%. There should be enough
coverage of higher rainfall rates to result in some flash flood
risk. Instability is less the farther west you go in MT, but
rainfall coverage will be greater, resulting in higher areal
averaged rainfall. The flood risk should gradually transition from
flash flood to areal flood/river flood as you go west across the
state.

Elsewhere, the Marginal risk was broadened across the Northern
Plains into the MS Valley along an elongated moisture axis.
Convective details are uncertain at this lead time, but that
entire corridor will have above average moisture and some
forcing.The most organized convective threat may end up over
portions of NE and SD Saturday night as stronger forcing ejects
into the area. However, there are also signals of organized
convective clusters within the moisture axis anywhere from AR to
IA. While convection is unlikely along this entire axis...where it
does develop rainfall rate potential will be high enough for
localized flash flooding.

Chenard

...Previous Discussion...

...Southeast...

Latest numerical guidance has shifted a majority of the rainfall
eastward enough compared with previous runs to preclude an upgrade
to a Slight risk. In addition...the spread of model
guidance both in terms of placement and amounts precluded an
upgrade. As mentioned previously...some of the region, especially
western parts of South Carolina and into the Appalachians, has
been very wet as of late and is well primed, so may by more
vulnerable to flooding concerns.

...Northern Rockies to High Plains...

The upper level low over the West during the Day 1 period will
weaken and shift northeastward, moving over the Northern Rockies to
High Plains region on Saturday. Moisture anomalies will continue
to be in the 90-90th percentile, supporting moderate to heavy
rainfall, with widespread QPF greater than 0.5-1" likely across
western and central Montana. There may not be a lot of instability
to work with, so any flood or flash flood threats should be mainly
localized with particular attention to burn scar locations. A
fairly broad marginal risk remained in place across much of
western and central Montana, into parts of northern Wyoming as
well.

Bann

Day 3
Valid 12Z Sun May 31 2026 - 12Z Mon Jun 01 2026

...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL STRETCHING FROM
MONTANA TO NORTHERN FLORIDA...

20Z Update: Expanded the Marginal risk to cover most of the
anomalous moisture plume that will extend from MT into the
Southeast U.S. in between troughing over the West and Northeast.
Large scale forcing is more subtle outside of the Northern
Plains/Rockies...but there should be some weak shortwaves
embedded within the weak flow. Global deterministic models,
ensemble means and AI models show a broad convective threat along
this entire corridor, with no clear area of higher focus. Thus at
the moment a large Marginal seems to handle the localized flash
flood risk that should exist. Some fine tuning of the Marginal
and/or focused Slight risk upgrades will be possible as we get
closer and convective mode/evolution becomes clearer.

Chenard

...Previous Discussion...

...Northern Rockies and Adjacent High Plains...
The upper level low which has been supporting the prolonged wet
period over the Northern Rockies will continue to move northward
across Montana slowly on Sunday. This results in surface low
pressure and associated surface front to makes its way out over the
Plains and gradually weaken while the mid and upper level
circulation keeps precipitation lingering over Montana and far
northern Wyoming. Moisture remains anomalously high but instability
still looks to be dependent upon cloud cover. As in the Day 2
period...any flood or flash flood threats should be mainly
localized with particular attention to burn scar locations.

...Southeast...
Until surface high pressure builds far enough southward into the
Southeast states to decrease coverage of lingering convection on
Sunday evening...the antecedent conditions keep a risk of flooding
concerns over the area.

Bann


Day 1 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/94epoints.txt__;!!DZ3fjg!7we_l73PKnUB_0qo1S853oUXeFktdonbUW7532LZT3zF= xlRciigC8ZJcAESLQZxz6VgitXrohvclL-9DYzsJzizNMSw$=20
Day 2 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/98epoints.txt__;!!DZ3fjg!7we_l73PKnUB_0qo1S853oUXeFktdonbUW7532LZT3zF= xlRciigC8ZJcAESLQZxz6VgitXrohvclL-9DYzsJQwcDIPk$=20
Day 3 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/99epoints.txt__;!!DZ3fjg!7we_l73PKnUB_0qo1S853oUXeFktdonbUW7532LZT3zF= xlRciigC8ZJcAESLQZxz6VgitXrohvclL-9DYzsJ_TmjDc4$=20

=3D =3D =3D
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FOUS30 KWBC 300830
QPFERD

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
430 AM EDT Sat May 30 2026

Day 1
Valid 12Z Sat May 30 2026 - 12Z Sun May 31 2026

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL ACROSS PORTIONS OF
MONTANA...

...Northern Rockies to the Plains...

Maintained the Slight risk across portions of Montana as a mid-=20
and upper-level system makes its way northward slowly today. The=20
system should foster locally intense rainfall rates...especially in
the eastern portion of the Slight Risk area...given moderately=20
steep lapse rates and some potential for enough breaks in cloud=20
cover. The HREF neighborhood probabilities of exceeding 1"/hr in=20
the 30-50% range, and 2"/hr around 10%. This results in HREF FFG=20
exceedance probabilities broadly over 25 percent. The RRFS shows a=20
similar evolution in roughly the same area but was not quite as=20
high with its probability of exceedance or with the probability of=20
1 inch per hour rainfall. Farther west;..the instability is=20
expected to be weaker but the greater coverage of rainfall looks=20
to offset the instability shortfall. As mentioned previously...the=20
flood risk should gradually transition from flash flood to areal=20
flood/river flood as you go west across the state.

A Marginal Risk area extending eastward from Montana and then
southward from the Northern Plains and Mid-Mississippi Valley was
largely left in place given the signal in the HREF for locally
heavy rainfall rates within an elongated moisture plume originating
from the Southeast US. It was done so despite convective details=20
remaining uncertain. The most organized convective threat may end=20
up over portions of NE and SD given a highly difluent flow aloft=20
and low level convergent flow. However, there are also signals of=20
organized convective clusters within the moisture axis anywhere=20
from Arkansas to Iowa, While convection is unlikely along this=20
entire axis...where it does develop rainfall rate potential will be
high enough for localized flash flooding.

...Southeast...

Latest numerical guidance continued to show locally heavy rainfall
today and tonight along and south of a boundary moving in from the
north. There was a bit of a westward expansion in the western
extent shown by the HREF and RRFS of the 1-inch per hour
probabilities and the probability of exceedance. As a result...the
Marginal Risk was expanded westward in parts of Georgia to Alabama.

Bann

Day 2
Valid 12Z Sun May 31 2026 - 12Z Mon Jun 01 2026

...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL STRETCHING FROM
MONTANA TO NORTHERN FLORIDA...

Any heavy to excessive rainfall should be located in or near a
plume of anomalous moisture plume that will extend from Montana=20
into the Southeast United State. Large scale forcing is more=20
subtle outside of the Northern Plains/Rockies...but there should be
some weak shortwave energy embedded within the weak flow that will
make them difficult or impossible to time. As this shortwave energy
encounters a late day atmosphere with MUCAPE values in excess of
3000 J per kg from the Plains into the Mississippi Valley and parts
of the Southeast US...storms have the potential to produce very
intense rainfall rates that approach or exceed flash flood
guidance along this entire corridor. A large and generally
unfocused Marginal Risk area still seems to handle the localized
nature of flash flood risk that should exist.=20

The Montana portion of the Marginal Risk has the strongest synoptic
forcing as a mid- and upper-level system gradually moves north of
the border...keeping the western part of the state in lingering=20
wrap-around rainfall before gradually tapering off.

Bann



Day 3
Valid 12Z Mon Jun 01 2026 - 12Z Tue Jun 02 2026

The probability of rainfall exceeding flash flood guidance is less
than 5 percent.=20

There are some hints in the guidance that the overall risk of
excessive rainfall is non-zero over the Plains from Kansas into
Colorado as models show a low level axis of moisture and
instability moving northward on Monday afternoon. The ensemble and deterministic QPF is fairly low...perhaps due to a component of low
level flow off the moisture. In addition...lingering deep moisture
may fuel some late day thunderstorms on Monday that are capable of
locally heavy rainfall but the model spread limits confidence.




Day 1 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/94epoints.txt__;!!DZ3fjg!9ooCQvdZ7TKESW2BfQNpFrjo_QsIGuGe6af90oR9ceMN= YUfhNMrlwEVhcNd2Pi25re6rqB5M6QbMytD6KrD9ocsSA1Q$=20
Day 2 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/98epoints.txt__;!!DZ3fjg!9ooCQvdZ7TKESW2BfQNpFrjo_QsIGuGe6af90oR9ceMN= YUfhNMrlwEVhcNd2Pi25re6rqB5M6QbMytD6KrD9gMj5WEg$=20
Day 3 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/99epoints.txt__;!!DZ3fjg!9ooCQvdZ7TKESW2BfQNpFrjo_QsIGuGe6af90oR9ceMN= YUfhNMrlwEVhcNd2Pi25re6rqB5M6QbMytD6KrD9uoIy-s4$=20

=3D =3D =3D
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FOUS30 KWBC 301554
QPFERD

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
1154 AM EDT Sat May 30 2026

Day 1
Valid 16Z Sat May 30 2026 - 12Z Sun May 31 2026

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL ACROSS PORTIONS OF
MONTANA...

16Z Update...

...Tennessee Valley...

Current radar and RAP mesoanalysis show a weak 925 mb circulation over
central TN that is caught between the front to the north and the low-
level WSWrly over MS/AL. The 12Z BMX sounding shows the atmosphere
remains weakly capped with a 1.9" PW, and >500 MLCAPE, RH at low=20
and mid levels >90%, and a warm cloud layer approaching 12,000ft=20
in depth. A nearby outflow boundary is also moving south into=20
southern TN this morning and is likely to trigger additional heavy thunderstorms this afternoon. There is not much in the way of=20
vertical wind shear, so storms will be fairly short lived. But up=20
to 2.5"/hr rainfall rates this afternoon and evening atop soils=20
that remain quite saturated led to an extension of the Marginal=20
Risk in the Southeast as far north and west as south-central TN.

Otherwise, some minor tweaks were made to the Marginal in the=20
Southeast and Northern and Central Plains, as well as the Slight=20
Risk in MT based on latest 12Z HREF and 12Z CAMs guidance. The=20
threat areas and rationale provided by night shift remain in good=20
shape as of this update.

Mullinax

---Previous Discussion---

...Northern Rockies to the Plains...

Maintained the Slight risk across portions of Montana as a mid-
and upper-level system makes its way northward slowly today. The
system should foster locally intense rainfall rates...especially in
the eastern portion of the Slight Risk area...given moderately
steep lapse rates and some potential for enough breaks in cloud
cover. The HREF neighborhood probabilities of exceeding 1"/hr in
the 30-50% range, and 2"/hr around 10%. This results in HREF FFG
exceedance probabilities broadly over 25 percent. The RRFS shows a
similar evolution in roughly the same area but was not quite as
high with its probability of exceedance or with the probability of
1 inch per hour rainfall. Farther west;..the instability is
expected to be weaker but the greater coverage of rainfall looks
to offset the instability shortfall. As mentioned previously...the
flood risk should gradually transition from flash flood to areal
flood/river flood as you go west across the state.

A Marginal Risk area extending eastward from Montana and then
southward from the Northern Plains and Mid-Mississippi Valley was
largely left in place given the signal in the HREF for locally
heavy rainfall rates within an elongated moisture plume originating
from the Southeast US. It was done so despite convective details
remaining uncertain. The most organized convective threat may end
up over portions of NE and SD given a highly difluent flow aloft
and low level convergent flow. However, there are also signals of
organized convective clusters within the moisture axis anywhere
from Arkansas to Iowa, While convection is unlikely along this
entire axis...where it does develop rainfall rate potential will be
high enough for localized flash flooding.

...Southeast...

Latest numerical guidance continued to show locally heavy rainfall
today and tonight along and south of a boundary moving in from the
north. There was a bit of a westward expansion in the western
extent shown by the HREF and RRFS of the 1-inch per hour
probabilities and the probability of exceedance. As a result...the
Marginal Risk was expanded westward in parts of Georgia to Alabama.

Bann

Day 2
Valid 12Z Sun May 31 2026 - 12Z Mon Jun 01 2026

...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL STRETCHING FROM
MONTANA TO NORTHERN FLORIDA...

Any heavy to excessive rainfall should be located in or near a
plume of anomalous moisture plume that will extend from Montana
into the Southeast United State. Large scale forcing is more
subtle outside of the Northern Plains/Rockies...but there should be
some weak shortwave energy embedded within the weak flow that will
make them difficult or impossible to time. As this shortwave energy
encounters a late day atmosphere with MUCAPE values in excess of
3000 J per kg from the Plains into the Mississippi Valley and parts
of the Southeast US...storms have the potential to produce very
intense rainfall rates that approach or exceed flash flood
guidance along this entire corridor. A large and generally
unfocused Marginal Risk area still seems to handle the localized
nature of flash flood risk that should exist.

The Montana portion of the Marginal Risk has the strongest synoptic
forcing as a mid- and upper-level system gradually moves north of
the border...keeping the western part of the state in lingering
wrap-around rainfall before gradually tapering off.

Bann



Day 3
Valid 12Z Mon Jun 01 2026 - 12Z Tue Jun 02 2026

The probability of rainfall exceeding flash flood guidance is less
than 5 percent.

There are some hints in the guidance that the overall risk of
excessive rainfall is non-zero over the Plains from Kansas into
Colorado as models show a low level axis of moisture and
instability moving northward on Monday afternoon. The ensemble and deterministic QPF is fairly low...perhaps due to a component of low
level flow off the moisture. In addition...lingering deep moisture
may fuel some late day thunderstorms on Monday that are capable of
locally heavy rainfall but the model spread limits confidence.




Day 1 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/94epoints.txt__;!!DZ3fjg!-mbo0MaiJ5BqRgXFgubIleaJdsnRfvdronGdFD9oOiNv= s0bTXAUXgyAms06Z25bbvrqnU2YjkO_IZAYVsSrdSTz-Bzc$=20
Day 2 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/98epoints.txt__;!!DZ3fjg!-mbo0MaiJ5BqRgXFgubIleaJdsnRfvdronGdFD9oOiNv= s0bTXAUXgyAms06Z25bbvrqnU2YjkO_IZAYVsSrdrBsNpUI$=20
Day 3 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/99epoints.txt__;!!DZ3fjg!-mbo0MaiJ5BqRgXFgubIleaJdsnRfvdronGdFD9oOiNv= s0bTXAUXgyAms06Z25bbvrqnU2YjkO_IZAYVsSrd79g1XEg$=20

=3D =3D =3D
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FOUS30 KWBC 302000
QPFERD

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
400 PM EDT Sat May 30 2026

Day 1
Valid 16Z Sat May 30 2026 - 12Z Sun May 31 2026

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL ACROSS PORTIONS OF
MONTANA...

16Z Update...

...Tennessee Valley...

Current radar and RAP mesoanalysis show a weak 925 mb circulation over
central TN that is caught between the front to the north and the low-
level WSWrly over MS/AL. The 12Z BMX sounding shows the atmosphere
remains weakly capped with a 1.9" PW, and >500 MLCAPE, RH at low
and mid levels >90%, and a warm cloud layer approaching 12,000ft
in depth. A nearby outflow boundary is also moving south into
southern TN this morning and is likely to trigger additional heavy thunderstorms this afternoon. There is not much in the way of
vertical wind shear, so storms will be fairly short lived. But up
to 2.5"/hr rainfall rates this afternoon and evening atop soils
that remain quite saturated led to an extension of the Marginal
Risk in the Southeast as far north and west as south-central TN.

Otherwise, some minor tweaks were made to the Marginal in the
Southeast and Northern and Central Plains, as well as the Slight
Risk in MT based on latest 12Z HREF and 12Z CAMs guidance. The
threat areas and rationale provided by night shift remain in good
shape as of this update.

Mullinax

---Previous Discussion---

...Northern Rockies to the Plains...

Maintained the Slight risk across portions of Montana as a mid-
and upper-level system makes its way northward slowly today. The
system should foster locally intense rainfall rates...especially in
the eastern portion of the Slight Risk area...given moderately
steep lapse rates and some potential for enough breaks in cloud
cover. The HREF neighborhood probabilities of exceeding 1"/hr in
the 30-50% range, and 2"/hr around 10%. This results in HREF FFG
exceedance probabilities broadly over 25 percent. The RRFS shows a
similar evolution in roughly the same area but was not quite as
high with its probability of exceedance or with the probability of
1 inch per hour rainfall. Farther west;..the instability is
expected to be weaker but the greater coverage of rainfall looks
to offset the instability shortfall. As mentioned previously...the
flood risk should gradually transition from flash flood to areal
flood/river flood as you go west across the state.

A Marginal Risk area extending eastward from Montana and then
southward from the Northern Plains and Mid-Mississippi Valley was
largely left in place given the signal in the HREF for locally
heavy rainfall rates within an elongated moisture plume originating
from the Southeast US. It was done so despite convective details
remaining uncertain. The most organized convective threat may end
up over portions of NE and SD given a highly difluent flow aloft
and low level convergent flow. However, there are also signals of
organized convective clusters within the moisture axis anywhere
from Arkansas to Iowa, While convection is unlikely along this
entire axis...where it does develop rainfall rate potential will be
high enough for localized flash flooding.

...Southeast...

Latest numerical guidance continued to show locally heavy rainfall
today and tonight along and south of a boundary moving in from the
north. There was a bit of a westward expansion in the western
extent shown by the HREF and RRFS of the 1-inch per hour
probabilities and the probability of exceedance. As a result...the
Marginal Risk was expanded westward in parts of Georgia to Alabama.

Bann

Day 2
Valid 12Z Sun May 31 2026 - 12Z Mon Jun 01 2026

...THERE IS A SLIGHT RISK FOR PORTIONS OF THE SOUTHEAST...

20Z Update...

...Southeast...

A nearby frontal boundary will become the focus for yet more strong thunderstorms over much of the Southeast on Sunday. Just south of
the front in southern SC, southern GA, and northern FL, this region
is a reservoir of >2.0" PWs that are available thanks in large part
to a southerly IVT that contains moisture originating from the
western Caribbean Sea. Area-averaged soundings suggest a
sufficiently unstable atmosphere (>1,000 K/kg MLCAPE), well
saturated 1000-500mb columns, and warm cloud layers up to 14,000ft
deep in some cases. The key in determining the full extent of the
flash flooding threat will be how much cloud debris from Saturday
and Saturday night's thunderstorm activity lingers into Sunday.
That said, weak capping inversions should allow for storms to
develop as early as late morning and soils in the area remain
rather saturated following such an active week-long stretch of
heavy rainfall. In collaboration with several Southeast WFOs, a
Slight Risk was added this cycle given the potential for scattered
instances of flash flooding.

...West Texas...

A Marginal Risk was introduced this cycle given the growing
consensus of global models and CAMs that were hinting at
thunderstorms firing over the Davis Mountains and along the
dryline. PWs surge to >1.0" in these areas as low-level SErly flow
introduces additional 850mb moisture flux into the region and a
sheared 500mb vort max approaching from northern Mexico. Sufficient
instability also appears to be present with MUCAPE up to 1,000=20
J/kg expected to be available. West Texas continues to have locally
sensitive soils in wake of recent rainfall as well. Given these=20
factors, a Marginal Risk was introduced for a localized flash=20
flood threat in West Texas Sunday afternoon and evening.=20

Mullinax

---Previous Discussion---

Any heavy to excessive rainfall should be located in or near a
plume of anomalous moisture plume that will extend from Montana
into the Southeast United State. Large scale forcing is more
subtle outside of the Northern Plains/Rockies...but there should be
some weak shortwave energy embedded within the weak flow that will
make them difficult or impossible to time. As this shortwave energy
encounters a late day atmosphere with MUCAPE values in excess of
3000 J per kg from the Plains into the Mississippi Valley and parts
of the Southeast US...storms have the potential to produce very
intense rainfall rates that approach or exceed flash flood
guidance along this entire corridor. A large and generally
unfocused Marginal Risk area still seems to handle the localized
nature of flash flood risk that should exist.

The Montana portion of the Marginal Risk has the strongest synoptic
forcing as a mid- and upper-level system gradually moves north of
the border...keeping the western part of the state in lingering
wrap-around rainfall before gradually tapering off.

Bann


Day 3
Valid 12Z Mon Jun 01 2026 - 12Z Tue Jun 02 2026

The probability of rainfall exceeding flash flood guidance is less
than 5 percent.

There remain some hints in latest 12Z guidance that the overall=20
risk of excessive rainfall is non-zero over the Plains from Kansas=20
into Colorado. Models show a low level axis of moisture and=20
instability moving northward on Monday afternoon but the placement
of the heaviest thunderstorm activity remains unclear. In=20
addition, portions of the Mid-South may also be at-risk for
Excessive Rainfall, but guidance remains murky on where storms will
initiate. Given these reasons, the Day 3 ERO remains free of
risk areas for the time being.

Bann/Mullinax


Day 1 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/94epoints.txt__;!!DZ3fjg!71fcvUA7T4rijAy10z8vAOrXCJZ707ogkhxHTiW-Y8EQ= sG356EKkUb4fRaOij9JKD7UOnZA6yG2R1Flw_VZ3pndJcOs$=20
Day 2 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/98epoints.txt__;!!DZ3fjg!71fcvUA7T4rijAy10z8vAOrXCJZ707ogkhxHTiW-Y8EQ= sG356EKkUb4fRaOij9JKD7UOnZA6yG2R1Flw_VZ3djfuxgo$=20
Day 3 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/99epoints.txt__;!!DZ3fjg!71fcvUA7T4rijAy10z8vAOrXCJZ707ogkhxHTiW-Y8EQ= sG356EKkUb4fRaOij9JKD7UOnZA6yG2R1Flw_VZ3rpnxz6w$=20

=3D =3D =3D
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FOUS30 KWBC 302246
QPFERD

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
646 PM EDT Sat May 30 2026

Day 1
Valid 2241Z Sun May 31 2026 - 12Z Sun May 31 2026

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL ACROSS PORTIONS OF
MONTANA INTO WESTERN SOUTH DAKOTA...

23z Update: Based on observational trends we expanded the Slight=20
risk into portions of western SD and the Marginal risk into=20
northeast CO. Ongoing convection in these areas is showing some=20
signs of training resulting in an isolated to scattered flash flood
risk. The greater coverage of higher rainfall rates is expected=20
over western SD, and do expect to see some FFG exceedance here=20
over the next several hours as convection gradually shifts east=20
while also backbuilding into the southerly low level flow. Recent=20
HRRR runs indicate localized totals around 3" and that seems=20
plausible.

Chenard

16Z Update...

...Tennessee Valley...

Current radar and RAP mesoanalysis show a weak 925 mb circulation over
central TN that is caught between the front to the north and the low-
level WSWrly over MS/AL. The 12Z BMX sounding shows the atmosphere
remains weakly capped with a 1.9" PW, and >500 MLCAPE, RH at low
and mid levels >90%, and a warm cloud layer approaching 12,000ft
in depth. A nearby outflow boundary is also moving south into
southern TN this morning and is likely to trigger additional heavy thunderstorms this afternoon. There is not much in the way of
vertical wind shear, so storms will be fairly short lived. But up
to 2.5"/hr rainfall rates this afternoon and evening atop soils
that remain quite saturated led to an extension of the Marginal
Risk in the Southeast as far north and west as south-central TN.

Otherwise, some minor tweaks were made to the Marginal in the
Southeast and Northern and Central Plains, as well as the Slight
Risk in MT based on latest 12Z HREF and 12Z CAMs guidance. The
threat areas and rationale provided by night shift remain in good
shape as of this update.

Mullinax

---Previous Discussion---

...Northern Rockies to the Plains...

Maintained the Slight risk across portions of Montana as a mid-
and upper-level system makes its way northward slowly today. The
system should foster locally intense rainfall rates...especially in
the eastern portion of the Slight Risk area...given moderately
steep lapse rates and some potential for enough breaks in cloud
cover. The HREF neighborhood probabilities of exceeding 1"/hr in
the 30-50% range, and 2"/hr around 10%. This results in HREF FFG
exceedance probabilities broadly over 25 percent. The RRFS shows a
similar evolution in roughly the same area but was not quite as
high with its probability of exceedance or with the probability of
1 inch per hour rainfall. Farther west;..the instability is
expected to be weaker but the greater coverage of rainfall looks
to offset the instability shortfall. As mentioned previously...the
flood risk should gradually transition from flash flood to areal
flood/river flood as you go west across the state.

A Marginal Risk area extending eastward from Montana and then
southward from the Northern Plains and Mid-Mississippi Valley was
largely left in place given the signal in the HREF for locally
heavy rainfall rates within an elongated moisture plume originating
from the Southeast US. It was done so despite convective details
remaining uncertain. The most organized convective threat may end
up over portions of NE and SD given a highly difluent flow aloft
and low level convergent flow. However, there are also signals of
organized convective clusters within the moisture axis anywhere
from Arkansas to Iowa, While convection is unlikely along this
entire axis...where it does develop rainfall rate potential will be
high enough for localized flash flooding.

...Southeast...

Latest numerical guidance continued to show locally heavy rainfall
today and tonight along and south of a boundary moving in from the
north. There was a bit of a westward expansion in the western
extent shown by the HREF and RRFS of the 1-inch per hour
probabilities and the probability of exceedance. As a result...the
Marginal Risk was expanded westward in parts of Georgia to Alabama.

Bann

Day 2
Valid 12Z Sun May 31 2026 - 12Z Mon Jun 01 2026

...THERE IS A SLIGHT RISK FOR PORTIONS OF THE SOUTHEAST...

20Z Update...

...Southeast...

A nearby frontal boundary will become the focus for yet more strong thunderstorms over much of the Southeast on Sunday. Just south of
the front in southern SC, southern GA, and northern FL, this region
is a reservoir of >2.0" PWs that are available thanks in large part
to a southerly IVT that contains moisture originating from the
western Caribbean Sea. Area-averaged soundings suggest a
sufficiently unstable atmosphere (>1,000 K/kg MLCAPE), well
saturated 1000-500mb columns, and warm cloud layers up to 14,000ft
deep in some cases. The key in determining the full extent of the
flash flooding threat will be how much cloud debris from Saturday
and Saturday night's thunderstorm activity lingers into Sunday.
That said, weak capping inversions should allow for storms to
develop as early as late morning and soils in the area remain
rather saturated following such an active week-long stretch of
heavy rainfall. In collaboration with several Southeast WFOs, a
Slight Risk was added this cycle given the potential for scattered
instances of flash flooding.

...West Texas...

A Marginal Risk was introduced this cycle given the growing
consensus of global models and CAMs that were hinting at
thunderstorms firing over the Davis Mountains and along the
dryline. PWs surge to >1.0" in these areas as low-level SErly flow
introduces additional 850mb moisture flux into the region and a
sheared 500mb vort max approaching from northern Mexico. Sufficient
instability also appears to be present with MUCAPE up to 1,000
J/kg expected to be available. West Texas continues to have locally
sensitive soils in wake of recent rainfall as well. Given these
factors, a Marginal Risk was introduced for a localized flash
flood threat in West Texas Sunday afternoon and evening.

Mullinax

---Previous Discussion---

Any heavy to excessive rainfall should be located in or near a
plume of anomalous moisture plume that will extend from Montana
into the Southeast United State. Large scale forcing is more
subtle outside of the Northern Plains/Rockies...but there should be
some weak shortwave energy embedded within the weak flow that will
make them difficult or impossible to time. As this shortwave energy
encounters a late day atmosphere with MUCAPE values in excess of
3000 J per kg from the Plains into the Mississippi Valley and parts
of the Southeast US...storms have the potential to produce very
intense rainfall rates that approach or exceed flash flood
guidance along this entire corridor. A large and generally
unfocused Marginal Risk area still seems to handle the localized
nature of flash flood risk that should exist.

The Montana portion of the Marginal Risk has the strongest synoptic
forcing as a mid- and upper-level system gradually moves north of
the border...keeping the western part of the state in lingering
wrap-around rainfall before gradually tapering off.

Bann


Day 3
Valid 12Z Mon Jun 01 2026 - 12Z Tue Jun 02 2026

The probability of rainfall exceeding flash flood guidance is less
than 5 percent.

There remain some hints in latest 12Z guidance that the overall
risk of excessive rainfall is non-zero over the Plains from Kansas
into Colorado. Models show a low level axis of moisture and
instability moving northward on Monday afternoon but the placement
of the heaviest thunderstorm activity remains unclear. In
addition, portions of the Mid-South may also be at-risk for
Excessive Rainfall, but guidance remains murky on where storms will
initiate. Given these reasons, the Day 3 ERO remains free of
risk areas for the time being.

Bann/Mullinax


Day 1 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/94epoints.txt__;!!DZ3fjg!_UzOi-uR3qnixupTFdhLgdgZWf88dCkaeV4eJuU9CQst= 4JG3TgD-Iy8uDrtDmItBxaU2pnRRGg-LUOpNw3dS4VxJpzk$=20
Day 2 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/98epoints.txt__;!!DZ3fjg!_UzOi-uR3qnixupTFdhLgdgZWf88dCkaeV4eJuU9CQst= 4JG3TgD-Iy8uDrtDmItBxaU2pnRRGg-LUOpNw3dS1h5Vqdg$=20
Day 3 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/99epoints.txt__;!!DZ3fjg!_UzOi-uR3qnixupTFdhLgdgZWf88dCkaeV4eJuU9CQst= 4JG3TgD-Iy8uDrtDmItBxaU2pnRRGg-LUOpNw3dSWHj7k8g$=20

=3D =3D =3D
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FOUS30 KWBC 310048
QPFERD

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
848 PM EDT Sat May 30 2026

Day 1
Valid 01Z Sun May 31 2026 - 12Z Sun May 31 2026

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL ACROSS PORTIONS OF
MONTANA INTO WESTERN SOUTH DAKOTA...

The Slight risk is maintained into tonight across much of central
and eastern MT into western SD. Highest rainfall rate potential
(1-2" per hour) will be across southeastern MT into western SD and
far northwest NE where instability persists along with periodic=20
backbuilding cells. Elsewhere a broad Marginal risk extends from SD
into NE/IA and south across portions of KS and MO. Overall should=20
be an active overnight of convection across this corridor as=20
mid/upper level forcing overruns the axis of better=20
moisture/instability and we see a nocturnal increase in the low=20
level jet. Cells should be moving enough to keep the flash flood=20
risk localized in nature, although there could be one or more=20
smaller scale backbuilding clusters that develop and locally=20
enhance the flash flood risk. Confidence in exactly where this=20
occurs remains too low to introduce any additional Slight risk=20
areas.

Chenard

Day 2
Valid 12Z Sun May 31 2026 - 12Z Mon Jun 01 2026

...THERE IS A SLIGHT RISK FOR PORTIONS OF THE SOUTHEAST...

20Z Update...

...Southeast...

A nearby frontal boundary will become the focus for yet more strong thunderstorms over much of the Southeast on Sunday. Just south of
the front in southern SC, southern GA, and northern FL, this region
is a reservoir of >2.0" PWs that are available thanks in large part
to a southerly IVT that contains moisture originating from the
western Caribbean Sea. Area-averaged soundings suggest a
sufficiently unstable atmosphere (>1,000 K/kg MLCAPE), well
saturated 1000-500mb columns, and warm cloud layers up to 14,000ft
deep in some cases. The key in determining the full extent of the
flash flooding threat will be how much cloud debris from Saturday
and Saturday night's thunderstorm activity lingers into Sunday.
That said, weak capping inversions should allow for storms to
develop as early as late morning and soils in the area remain
rather saturated following such an active week-long stretch of
heavy rainfall. In collaboration with several Southeast WFOs, a
Slight Risk was added this cycle given the potential for scattered
instances of flash flooding.

...West Texas...

A Marginal Risk was introduced this cycle given the growing
consensus of global models and CAMs that were hinting at
thunderstorms firing over the Davis Mountains and along the
dryline. PWs surge to >1.0" in these areas as low-level SErly flow
introduces additional 850mb moisture flux into the region and a
sheared 500mb vort max approaching from northern Mexico. Sufficient
instability also appears to be present with MUCAPE up to 1,000
J/kg expected to be available. West Texas continues to have locally
sensitive soils in wake of recent rainfall as well. Given these
factors, a Marginal Risk was introduced for a localized flash
flood threat in West Texas Sunday afternoon and evening.

Mullinax

---Previous Discussion---

Any heavy to excessive rainfall should be located in or near a
plume of anomalous moisture plume that will extend from Montana
into the Southeast United State. Large scale forcing is more
subtle outside of the Northern Plains/Rockies...but there should be
some weak shortwave energy embedded within the weak flow that will
make them difficult or impossible to time. As this shortwave energy
encounters a late day atmosphere with MUCAPE values in excess of
3000 J per kg from the Plains into the Mississippi Valley and parts
of the Southeast US...storms have the potential to produce very
intense rainfall rates that approach or exceed flash flood
guidance along this entire corridor. A large and generally
unfocused Marginal Risk area still seems to handle the localized
nature of flash flood risk that should exist.

The Montana portion of the Marginal Risk has the strongest synoptic
forcing as a mid- and upper-level system gradually moves north of
the border...keeping the western part of the state in lingering
wrap-around rainfall before gradually tapering off.

Bann


Day 3
Valid 12Z Mon Jun 01 2026 - 12Z Tue Jun 02 2026

The probability of rainfall exceeding flash flood guidance is less
than 5 percent.

There remain some hints in latest 12Z guidance that the overall
risk of excessive rainfall is non-zero over the Plains from Kansas
into Colorado. Models show a low level axis of moisture and
instability moving northward on Monday afternoon but the placement
of the heaviest thunderstorm activity remains unclear. In
addition, portions of the Mid-South may also be at-risk for
Excessive Rainfall, but guidance remains murky on where storms will
initiate. Given these reasons, the Day 3 ERO remains free of
risk areas for the time being.

Bann/Mullinax


Day 1 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/94epoints.txt__;!!DZ3fjg!7z1PV5kibJsw7ioDubbxKV9f0LcD__edHvdTUpu-3RsP= m7eIp4X-trpImGSHuM6M6ZKt6uZFTFGNoTyfs4kED5Vzino$=20
Day 2 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/98epoints.txt__;!!DZ3fjg!7z1PV5kibJsw7ioDubbxKV9f0LcD__edHvdTUpu-3RsP= m7eIp4X-trpImGSHuM6M6ZKt6uZFTFGNoTyfs4kEeTraVI8$=20
Day 3 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/99epoints.txt__;!!DZ3fjg!7z1PV5kibJsw7ioDubbxKV9f0LcD__edHvdTUpu-3RsP= m7eIp4X-trpImGSHuM6M6ZKt6uZFTFGNoTyfs4kEYy7Pq4w$=20

=3D =3D =3D
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FOUS30 KWBC 310825
QPFERD

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
425 AM EDT Sun May 31 2026

Day 1
Valid 12Z Sun May 31 2026 - 12Z Mon Jun 01 2026

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL OVER PORTIONS OF
THE NORTHERN ROCKIES AND THE SOUTHEAST UNITED STATES...

Northern Rockies...
With rainfall on-going from Saturday due to a slow moving mid- and
upper-level system over the northern Rockies...opted to keep=20
portions of Montana and nearby Wyoming and the far western Dakotas=20
in a Slight Risk area during the new Day 1 period. The expectation=20
is that rainfall intensities will not be as high as they were on=20
Saturday but the cumulative effect of an additional 1+ inch amounts
on top of what has already fallen has the potential to produce=20
flooding concerns today. The Slight risk area was extended into far
western South Dakota where MRMS showed 3+ inches having fallen on=20
Saturday evening and was susceptible to flooding from even modest=20
rainfall amounts.

Southeast US...
Also introduced a Slight Risk area over portions of the Southeast
US where some model agreement has developed...although the
agreement was far from unanimous. Neither the HREF or RRFS showed=20
a strong signal for exceedance of flash flood guidance but showed=20
about 20 percent neighborhood probabilities of rainfall exceeding 2
inches. At the same time...a spaghetti plot of SREF QPF showed=20
decent amount of ARW members with QPF at 2 inch and 3 inch amounts.
That was largely supported by the GEFS. Given the 2 to 2.25 inch=20 precipitable water values and the amount of instability in the area
that could support intense rainfall rates...opted to include a=20
Slight Risk at this point.

Elsewhere...maintained the broad and largely unfocused Marginal
Risk area in between given the lack of clear forcing mechanism, the
light flow aloft and the broad pool of instability along and south
of a quasi-stationary boundary.=20=20

Bann

Day 2
Valid 12Z Mon Jun 01 2026 - 12Z Tue Jun 02 2026

...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL OVER PORTIONS OF
THE NORTHERN ROCKIES AND PARTS OF THE PLAINS...

Northern Rockies...=20
Introduced a Marginal Risk area in the northern Rockies where=20 moisture/precipitation lingers as a slow moving mid- and upper-=20
level system pulls away. The concern is not so much for rainfall=20
intensity at this point but for the cumulative effect of the=20
additional rain on top of what has fallen in the previous few days.
The concern is also fairly limited in terms of duration as=20
rainfall does come to an end during the middle- to latter-part of=20
the period.

Western High Plains...
Also introduced a Marginal Risk area mainly in the western portion
of Kansas/Nebraska as an axis of low level moisture begins to=20
return northward during the day. Placement of the QPF and any=20
associated risk of excessive rainfall remains somewhat tenuous.=20
Concern is that the instability should be enough that the QPF=20
amounts approaching or exceeding 2 inches from the UKMET/NAM and=20
GFS would be delivered quickly. A

Southeast US...
Portions of the Mid-South/Southeast may also be at-risk for=20
Excessive Rainfall, but guidance remains murky on where storms will
initiate. Given these reasons, the Day 2 ERO remains free of risk=20
areas for the time being.

Mullinax/Bann

Day 3
Valid 12Z Tue Jun 02 2026 - 12Z Wed Jun 03 2026

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL OVER PORTIONS OF
NEW MEXICO AND A SMALL PORTION OF WEST TEXAS...

A plume of Gulf-sourced moisture will be drawn northward into the=20
southern Rockies/drifting east over the southern High Plains/west=20
Texas to maintain a Slight Risk area for excessive rainfall on
Tuesday into Tuesday night from portions of New Mexico into west=20
Texas. Farther north...warm moist air will advect along a low=20
level convergence zone with early June heating that has the=20
potential for locally heavy rainfall over portions of the western
High Plains into the Dakotas.

Bann


Day 1 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/94epoints.txt__;!!DZ3fjg!-5hgMhGXcmwogx9qw1GvsYWjfqEWvzjzCRYMvm-gVaMM= iTn_Ilt-NiNA-GKncC5W-DljKUwIbhYxciMyP_xn4g6g-qU$=20
Day 2 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/98epoints.txt__;!!DZ3fjg!-5hgMhGXcmwogx9qw1GvsYWjfqEWvzjzCRYMvm-gVaMM= iTn_Ilt-NiNA-GKncC5W-DljKUwIbhYxciMyP_xntiwh_xg$=20
Day 3 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/99epoints.txt__;!!DZ3fjg!-5hgMhGXcmwogx9qw1GvsYWjfqEWvzjzCRYMvm-gVaMM= iTn_Ilt-NiNA-GKncC5W-DljKUwIbhYxciMyP_xnjcuZ0AY$=20

=3D =3D =3D
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FOUS30 KWBC 311558
QPFERD

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
1158 AM EDT Sun May 31 2026

Day 1
Valid 16Z Sun May 31 2026 - 12Z Mon Jun 01 2026

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL FOR PORTIONS OF=20
MONTANA TO THE BLACK HILLS, CENTRAL MISSOURI, AND THE SOUTHEAST=20
UNITED STATES...

Missouri...
Raised a Slight Risk for central Missouri.
Ongoing progressive activity across a stationary front is=20
generally producing 1-2" rainfall over central Missouri. 12Z=20
guidance is in pretty good agreement on an MCS tracking over=20
Missouri late tonight. That should be fairly progressive as well,=20
but veering of the low level flow may make for inflow parallel to=20
the orientation and increased duration overnight. Much of this area
has lower FFG (generally 2"/3hr), so the combination of these two=20
rounds could cause scattered flash flooding. Will need to monitor=20 CAMs/boundaries for further details to this overnight activity. The
RRFS is hotter than other models as usual, but the 12Z is notable=20
a broader span of coverage from the KC metro to the StL metro, so=20
either of those could be in greater play tonight and warrant a=20
Slight expansion to them.

Montana to the Black Hills...=20
Maintained the Slight Risk for portions of Montana and nearby=20
Wyoming and the far western Dakotas, now including more of the
Black Hills. Rainfall intensity will remain lower than yesterday,=20
but an additional 1-2" brings flooding concerns, especially where
the 3hr FFG is below 1.5" in north-central MT and western SD.

Southeast US...
Maintained the Slight Risk along a cold front over southern=20
GA/northern FL into southeast AL given agreement of 12Z CAM=20
guidance focusing 1-3"+ QPF on this area. PW rises from 2 to 2.25"=20
and MLCAPE should reach 2000 J/kg this afternoon supporting heavy=20
rain. Repeating activity is expected with 20kt Wly deep layer flow=20
keeping activity alive along the frontal forcing. Activity over the
eastern FL peninsula will need to be monitored. As of now the
Marginal Risk was expanded over Cape Canaveral on account of sea
breeze based convection possibly getting held up there. The focus
may be just west of Miami, but will continue to monitor.

Elsewhere...trimmed the broad Marginal Risk where possible
including in eastern MS and western KY. Expanded east a bit in
MN/IA and southeastern KY given 12Z consensus. Frontal and low
levels boundaries will provide some focus in the Gulf-sourced
moisture plume and the broad pool of instability.


Jackson


Day 2
Valid 12Z Mon Jun 01 2026 - 12Z Tue Jun 02 2026

...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL OVER PORTIONS OF
THE NORTHERN ROCKIES AND PARTS OF THE PLAINS...

Northern Rockies...
Introduced a Marginal Risk area in the northern Rockies where moisture/precipitation lingers as a slow moving mid- and upper-
level system pulls away. The concern is not so much for rainfall
intensity at this point but for the cumulative effect of the
additional rain on top of what has fallen in the previous few days.
The concern is also fairly limited in terms of duration as
rainfall does come to an end during the middle- to latter-part of
the period.

Western High Plains...
Also introduced a Marginal Risk area mainly in the western portion
of Kansas/Nebraska as an axis of low level moisture begins to
return northward during the day. Placement of the QPF and any
associated risk of excessive rainfall remains somewhat tenuous.
Concern is that the instability should be enough that the QPF
amounts approaching or exceeding 2 inches from the UKMET/NAM and
GFS would be delivered quickly. A

Southeast US...
Portions of the Mid-South/Southeast may also be at-risk for
Excessive Rainfall, but guidance remains murky on where storms will
initiate. Given these reasons, the Day 2 ERO remains free of risk
areas for the time being.

Mullinax/Bann


Day 3
Valid 12Z Tue Jun 02 2026 - 12Z Wed Jun 03 2026

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL OVER PORTIONS OF
NEW MEXICO AND A SMALL PORTION OF WEST TEXAS...

A plume of Gulf-sourced moisture will be drawn northward into the
southern Rockies/drifting east over the southern High Plains/west
Texas to maintain a Slight Risk area for excessive rainfall on
Tuesday into Tuesday night from portions of New Mexico into west
Texas. Farther north...warm moist air will advect along a low
level convergence zone with early June heating that has the
potential for locally heavy rainfall over portions of the western
High Plains into the Dakotas.

Bann


Day 1 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/94epoints.txt__;!!DZ3fjg!6ymt8JEilN9FzXPn-rMFVf3zsl3CYXiqobx09aCDIx1s= I2wDmU0S7q7pE5YqYvMZDfOeRkFvkadA4bMXJgHzcZUn1xc$=20
Day 2 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/98epoints.txt__;!!DZ3fjg!6ymt8JEilN9FzXPn-rMFVf3zsl3CYXiqobx09aCDIx1s= I2wDmU0S7q7pE5YqYvMZDfOeRkFvkadA4bMXJgHzVYSVTtY$=20
Day 3 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/99epoints.txt__;!!DZ3fjg!6ymt8JEilN9FzXPn-rMFVf3zsl3CYXiqobx09aCDIx1s= I2wDmU0S7q7pE5YqYvMZDfOeRkFvkadA4bMXJgHzFfx-OaY$=20

=3D =3D =3D
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FOUS30 KWBC 311958
QPFERD

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
358 PM EDT Sun May 31 2026

Day 1
Valid 16Z Sun May 31 2026 - 12Z Mon Jun 01 2026

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL FOR PORTIONS OF
MONTANA TO THE BLACK HILLS, CENTRAL MISSOURI, AND THE SOUTHEAST
UNITED STATES...

Missouri...
Raised a Slight Risk for central Missouri.
Ongoing progressive activity across a stationary front is
generally producing 1-2" rainfall over central Missouri. 12Z
guidance is in pretty good agreement on an MCS tracking over
Missouri late tonight. That should be fairly progressive as well,
but veering of the low level flow may make for inflow parallel to
the orientation and increased duration overnight. Much of this area
has lower FFG (generally 2"/3hr), so the combination of these two
rounds could cause scattered flash flooding. Will need to monitor CAMs/boundaries for further details to this overnight activity. The
RRFS is hotter than other models as usual, but the 12Z is notable
a broader span of coverage from the KC metro to the StL metro, so
either of those could be in greater play tonight and warrant a
Slight expansion to them.

Montana to the Black Hills...
Maintained the Slight Risk for portions of Montana and nearby
Wyoming and the far western Dakotas, now including more of the
Black Hills. Rainfall intensity will remain lower than yesterday,
but an additional 1-2" brings flooding concerns, especially where
the 3hr FFG is below 1.5" in north-central MT and western SD.

Southeast US...
Maintained the Slight Risk along a cold front over southern
GA/northern FL into southeast AL given agreement of 12Z CAM
guidance focusing 1-3"+ QPF on this area. PW rises from 2 to 2.25"
and MLCAPE should reach 2000 J/kg this afternoon supporting heavy
rain. Repeating activity is expected with 20kt Wly deep layer flow
keeping activity alive along the frontal forcing. Activity over the
eastern FL peninsula will need to be monitored. As of now the
Marginal Risk was expanded over Cape Canaveral on account of sea
breeze based convection possibly getting held up there. The focus
may be just west of Miami, but will continue to monitor.

Elsewhere...trimmed the broad Marginal Risk where possible
including in eastern MS and western KY. Expanded east a bit in
MN/IA and southeastern KY given 12Z consensus. Frontal and low
levels boundaries will provide some focus in the Gulf-sourced
moisture plume and the broad pool of instability.


Jackson


Day 2
Valid 12Z Mon Jun 01 2026 - 12Z Tue Jun 02 2026

...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL OVER PORTIONS OF
THE NORTHERN ROCKIES, GREAT PLAINS, AND MID-SOUTH...

Northern Rockies...
Precipitation lingers over northwest Montana as a slow moving mid-
and upper-level system lingers over the Canadian border. The=20
cumulative effect of the additional 1-2" rain (12Z HREF and REFS=20
consensus) maintains a limited risk for additional flooding=20
concerns.

Central Plains...=20
Expanded the Marginal Risk more into Northeast Colorado and into
more of north-central Oklahoma while trimming out the heart of the
Nebraska Sandhills. SSEly low level flow will increase over the=20
central Plains through the morning and promote strong diurnal
heating. Late afternoon High Plains activity should track east over
the central Plains.

Mid-South...
MCS activity is expected tonight over Missouri. This should=20=20
track from southeastern MO and over much of the Mid-South through=20
the morning with potential for additional evening activity along
remnant boundaries. Moist low level flow veers westerly late=20
tonight over the region which should be parallel to at least=20
segments of the activity and increase heavy rainfall duration at=20
least locally. 12Z CAM consensus paints a fairly decent heavy QPF=20
footprint across the Mid-South with 1-3"+ likely through the day.=20
The 18Z HRRR essentially agrees with the tracks of 12Z CAMs along
with the later additional activity. Raised a Marginal Risk for the
Mid- South on account of the ingredients and CAM output along with
3hr FFG around 2.5".

West Texas into New Mexico...
South-southeasterly low level flow intensifies Monday afternoon,
promoting decent westward expansion of Gulf moisture across the
Pecos River Valley to the Sacramento Mountains and south to the Big
Bend. Diurnally driven activity is a sure bet on the Davis and
Sacramento Mtns. How much activity spreads from the terrain remains
to be seen. For now the Marginal Risk was trimmed a bit on the
north and expanded over the Big Bend based on 12Z CAM consensus.


Jackson


Day 3
Valid 12Z Tue Jun 02 2026 - 12Z Wed Jun 03 2026

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL OVER PORTIONS OF
EASTERN NEW MEXICO AND WEST TEXAS...

...West Texas into New Mexico...
Southeasterly low level flow backs further easterly Tuesday
bringing more Gulf-sourced moisture across West Texas and southeast
New Mexico than was present on Monday. Terrain driven activity
should spread across this area with QPF generally in the 1-2"
range. Slow moving activity should result in scattered flash
flooding, especially over sensitive areas such as burn scars and
steeper terrain. The Slight Risk was trimmed a bit to exclude El
Paso based on 12Z consensus QPF.=20

...Great Plains...
Warm moist air surges up the Plains in earnest starting Monday
night. Sufficient shear from a trough over the Northern Rockies,
forcing along a low level convergence zones, and early June=20
heating should promote heavy/potentially organized thunderstorms
throughout the Great Plains. A Marginal Risk is maintained from the
Dakotas to the Texas Panhandle.

...North Florida through the Gulf Coast...
A Marginal Risk has been raised from east Texas through the
Florida/Georgia border. A slow moving cold front stretching from=20
Georgia to east Texas Tuesday morning drifts south through the Gulf
Coast Tuesday night. High moisture laden air pools ahead of the=20
front with a 2" PW swath from north FL to east Texas in the=20
afternoon which is 2 sigma above normal. Repeating heavy=20
thunderstorms should occur along this corridor and result in a=20
localized flash flood risk.=20


Jackson


Day 1 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/94epoints.txt__;!!DZ3fjg!5dH2Bd3SeNtiNDxGNM8CxUf-KHXepOvkJihalbviu7h0= pWVkxWPB_FDcUPdtfSxqvd0iLCufCL-SJwVc1V7C2mqB43M$=20
Day 2 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/98epoints.txt__;!!DZ3fjg!5dH2Bd3SeNtiNDxGNM8CxUf-KHXepOvkJihalbviu7h0= pWVkxWPB_FDcUPdtfSxqvd0iLCufCL-SJwVc1V7CXT7F73E$=20
Day 3 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/99epoints.txt__;!!DZ3fjg!5dH2Bd3SeNtiNDxGNM8CxUf-KHXepOvkJihalbviu7h0= pWVkxWPB_FDcUPdtfSxqvd0iLCufCL-SJwVc1V7CUjoLXPQ$=20

=3D =3D =3D
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FOUS30 KWBC 010053
QPFERD

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
853 PM EDT Sun May 31 2026

Day 1
Valid 01Z Mon Jun 01 2026 - 12Z Mon Jun 01 2026

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL FOR PORTIONS OF
EASTERN KS AND CENTRAL MISSOURI...

...Kansas and Missouri...
Expanded the Slight risk with this update across most of central=20
MO and portions of eastern KS. As of 01z a surface low is situated=20
near the KS/OK border, with extreme instability (MLCAPE of=20
4000-5000 j/kg) over eastern KS and southwestern MO. Recent=20
observations show increasing low level convergence ahead of this=20
low over eastern KS, and expect convection to initiate along this=20 convergence axis this evening. Supercells will be possible, locally
enhancing rainfall rates. Storm motion vectors are off to the=20
northeast at ~30 kts, however right moving supercell motions are=20
only around 10 kts. There is a lot of mid/upper level dry air which
may support cell forward propagation, but given the instability in
place and supercell motions, there is probably still an=20
opportunity for isolated to scattered flash flooding from this=20
activity.=20

While not the strongest low level jet, there will likely be enough
of a nocturnal uptick in low level moisture transport to result in
upscale growth of convection as it moves into MO during the=20
overnight hours. The orientation of convection and weak corfidi=20
vectors suggest some training potential, and think scattered flash=20
flooding is probable, with rainfall locally exceeding 3".

...Southeast...
Localized flash flooding will remain possible this evening over=20
the Southeast. A developing surface low off the coast may locally=20
enhance convection for a few hours near the SC coast, but=20
confidence on this remains low, as the better activity could very=20
well remain offshore.

...West TX...=20
A localized flash flood risk continues along the dryline in west=20
TX, although this activity should weaken and diminish shortly.

...Dakotas...
Enhanced convergence near an occluded front will result in an=20
isolated flash flood risk this evening across portions of the=20
Dakotas, where convection is showing signs of some backbuilding.=20
Higher rainfall totals and any flash flooding should stay small=20
scale, and thus the Marginal risk should cover the threat.

Chenard


Day 2
Valid 12Z Mon Jun 01 2026 - 12Z Tue Jun 02 2026

...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL OVER PORTIONS OF
THE NORTHERN ROCKIES, GREAT PLAINS, AND MID-SOUTH...

Northern Rockies...
Precipitation lingers over northwest Montana as a slow moving mid-
and upper-level system lingers over the Canadian border. The
cumulative effect of the additional 1-2" rain (12Z HREF and REFS
consensus) maintains a limited risk for additional flooding
concerns.

Central Plains...
Expanded the Marginal Risk more into Northeast Colorado and into
more of north-central Oklahoma while trimming out the heart of the
Nebraska Sandhills. SSEly low level flow will increase over the
central Plains through the morning and promote strong diurnal
heating. Late afternoon High Plains activity should track east over
the central Plains.

Mid-South...
MCS activity is expected tonight over Missouri. This should
track from southeastern MO and over much of the Mid-South through
the morning with potential for additional evening activity along
remnant boundaries. Moist low level flow veers westerly late
tonight over the region which should be parallel to at least
segments of the activity and increase heavy rainfall duration at
least locally. 12Z CAM consensus paints a fairly decent heavy QPF
footprint across the Mid-South with 1-3"+ likely through the day.
The 18Z HRRR essentially agrees with the tracks of 12Z CAMs along
with the later additional activity. Raised a Marginal Risk for the
Mid- South on account of the ingredients and CAM output along with
3hr FFG around 2.5".

West Texas into New Mexico...
South-southeasterly low level flow intensifies Monday afternoon,
promoting decent westward expansion of Gulf moisture across the
Pecos River Valley to the Sacramento Mountains and south to the Big
Bend. Diurnally driven activity is a sure bet on the Davis and
Sacramento Mtns. How much activity spreads from the terrain remains
to be seen. For now the Marginal Risk was trimmed a bit on the
north and expanded over the Big Bend based on 12Z CAM consensus.


Jackson


Day 3
Valid 12Z Tue Jun 02 2026 - 12Z Wed Jun 03 2026

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL OVER PORTIONS OF
EASTERN NEW MEXICO AND WEST TEXAS...

...West Texas into New Mexico...
Southeasterly low level flow backs further easterly Tuesday
bringing more Gulf-sourced moisture across West Texas and southeast
New Mexico than was present on Monday. Terrain driven activity
should spread across this area with QPF generally in the 1-2"
range. Slow moving activity should result in scattered flash
flooding, especially over sensitive areas such as burn scars and
steeper terrain. The Slight Risk was trimmed a bit to exclude El
Paso based on 12Z consensus QPF.

...Great Plains...
Warm moist air surges up the Plains in earnest starting Monday
night. Sufficient shear from a trough over the Northern Rockies,
forcing along a low level convergence zones, and early June
heating should promote heavy/potentially organized thunderstorms
throughout the Great Plains. A Marginal Risk is maintained from the
Dakotas to the Texas Panhandle.

...North Florida through the Gulf Coast...
A Marginal Risk has been raised from east Texas through the
Florida/Georgia border. A slow moving cold front stretching from
Georgia to east Texas Tuesday morning drifts south through the Gulf
Coast Tuesday night. High moisture laden air pools ahead of the
front with a 2" PW swath from north FL to east Texas in the
afternoon which is 2 sigma above normal. Repeating heavy
thunderstorms should occur along this corridor and result in a
localized flash flood risk.


Jackson


Day 1 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/94epoints.txt__;!!DZ3fjg!7_CplQTtWXo-TGDR802zm7ssyqtYuKAbTZJpwjPmXMmw= ijGGM0x3MoK6mOZZzoCLItIkOb5KYXzG-iYi0Yaqe3EHLFU$=20
Day 2 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/98epoints.txt__;!!DZ3fjg!7_CplQTtWXo-TGDR802zm7ssyqtYuKAbTZJpwjPmXMmw= ijGGM0x3MoK6mOZZzoCLItIkOb5KYXzG-iYi0YaqG5CqvvA$=20
Day 3 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/99epoints.txt__;!!DZ3fjg!7_CplQTtWXo-TGDR802zm7ssyqtYuKAbTZJpwjPmXMmw= ijGGM0x3MoK6mOZZzoCLItIkOb5KYXzG-iYi0YaqsZuUyT8$=20

=3D =3D =3D
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FOUS30 KWBC 010807
QPFERD

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
407 AM EDT Mon Jun 1 2026

Day 1
Valid 12Z Mon Jun 01 2026 - 12Z Tue Jun 02 2026

...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL OVER PORTIONS OF
THE NORTHERN ROCKIES, GREAT PLAINS, AND MID-SOUTH...

...Northern Rockies...
A closed mid-level system will continue to slowly move across=20
Montana during the period, bringing an additional 1 to 2 inches of
rainfall. The Marginal Risk for isolated / localized flooding was=20
maintained with minimal adjustments based on the 00Z guidance.

...Mid-South...
Early morning MCS across eastern Kansas and Missouri is expected=20
to continue to move east/southeast through this morning toward the=20
TN Valley and Mid-South. Forward propagation after 12Z should=20
overall limit widespread heavy rainfall, but some elements may=20
locally train/repeat over the same area bringing a risk of flash=20
flooding, particularly early in the period across eastern Missouri.
While that activity is likely to wane by late morning, additional=20 thunderstorms are expected to fire up along remnant outflow=20
boundaries to the south and west across Mississippi and Alabama.=20
Pockets of 1-2" in a short duration may result in isolated flooding,
with the overall threat maintained at the Marginal Risk level.=20

...Central Plains...
Broad upper level forcing across the region along with modest
southeasterly low level flow will bring isolated to scattered
diurnally driven convection today across the High Plains that will
gradually track eastward through south central Nebraska and western
to central Kansas into this evening and overnight. The Marginal=20
Risk was maintained with a few adjustments based on the latest=20
model guidance.=20

...West Texas into New Mexico...
Modest forcing for ascent across the region combined with low level southeasterly flow will bring westward Gulf moisture. Diurnal
convection is expected across the Davis and Sacramento Mtns. Based
on the 00Z hi-res models, some of this convection may spread away
from the terrain, but overall expected to be isolated in coverage
with a localized flash flood risk today.=20


Taylor


Day 2
Valid 12Z Tue Jun 02 2026 - 12Z Wed Jun 03 2026

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL ACROSS PORTIONS OF
WEST TEXAS INTO NEW MEXICO...

...West Texas into New Mexico...
By Tuesday, the latest model guidance suggests greater moisture
will expand westward toward the region (compared to today) with PW
anomalies approaching 1.5 to 2 std deviations above normal. Another
round of terrain driven convection is expected that spreads east
across the area. Overall, pockets of 1 to 2 inches are possible
with resulting isolated/scattered flash flooding, particularly for
any sensitive locations such as burn scars and steeper terrain.=20

...Great Plains...
Large scale forcing for ascent across the High Plains will work
with an increasing amount of low level moisture to produce several
clusters of thunderstorms during the period capable of producing
heavy rainfall - one area of concern is across eastern to central
Kansas where the latest guidance has pointed toward the potential
for several repeating clusters of intense rain rates. Some of this
additional rainfall may fall on areas expected to see heavy
rainfall today. A second area of concern is the Northern Plains=20
where there is likely to be better forcing with the proximity to=20
the mid/upper level feature. Here, moisture isn't as high and storm
motions may be faster, but potential exists for intense rain rates
and locally heavy rainfall. Both of these areas (Dakotas and=20
western/central KS) may need upgrades to Slight Risk if trends=20
continue with future model cycles but for now, have maintained the=20
Marginal given some of the uncertainty heading into Tuesday.=20

...North Florida through the Gulf Coast...
A cold front will slowly advance southward across the region during
the day Tuesday, with copious amounts of moisture pooling along and
ahead of it. Thunderstorms are likely to develop, particularly=20
focused on the Florida Panhandle to northeast Florida where the=20
latest guidance points to the potential of 1-3" locally. Localized=20
/ isolated flash flooding will be possible due to the expected=20
intense rain rates and overall slower storm motions.=20

Taylor


Day 3
Valid 12Z Wed Jun 03 2026 - 12Z Thu Jun 04 2026

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL OVER PORTIONS OF WEST
TEXAS...

...West Texas into New Mexico...
A greater signal exists for a stronger mid-level shortwave to move
across the southern High Plains on Wednesday. This feature,=20
combined with the continued relatively higher moisture in place,=20
should result in robust convection to develop across far eastern=20
New Mexico into western Texas, particularly across the TX Panhandle.
A Slight Risk was maintained for the potential of isolated to=20
scattered flash flooding, some of which may fall on similar areas=20
as Tuesday.=20

...Great Plains...
The active pattern across the Plains is expected again on
Wednesday with a plume of relatively higher moisture extending from
Texas all the way north into the Northern Plains. Daytime
convection is expected to fire up across the Plains and then move east/southeast into the evening/overnight hours. Several organized
clusters of convection are likely with pockets of locally heavy
rainfall. For now, a broad Marginal Risk remains in place for
isolated instances of flash flooding.=20


Taylor


Day 1 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/94epoints.txt__;!!DZ3fjg!4A1PknCIOhTinqgw64mF-nMrl-flB-G8EMffCQYE2dWC= X_E9yHrBNtJfSuknPPp-b3bPXZrm3DIfc3s-3Ux2fg09uRA$=20
Day 2 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/98epoints.txt__;!!DZ3fjg!4A1PknCIOhTinqgw64mF-nMrl-flB-G8EMffCQYE2dWC= X_E9yHrBNtJfSuknPPp-b3bPXZrm3DIfc3s-3Ux27ctk39g$=20
Day 3 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/99epoints.txt__;!!DZ3fjg!4A1PknCIOhTinqgw64mF-nMrl-flB-G8EMffCQYE2dWC= X_E9yHrBNtJfSuknPPp-b3bPXZrm3DIfc3s-3Ux26AzMTDo$=20

=3D =3D =3D
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FOUS30 KWBC 011554
QPFERD

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
1154 AM EDT Mon Jun 1 2026

Day 1
Valid 16Z Mon Jun 01 2026 - 12Z Tue Jun 02 2026

...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL OVER PORTIONS OF
THE NORTHERN ROCKIES, GREAT PLAINS, AND MID-SOUTH...

16Z Update...

...Central Gulf Coast...

The Marginal Risk area over the Mid-South was expanded southward=20
to the central Gulf Coast for this update. Soils remains quite=20
saturated in eastern LA, southern MS, southern AL, and the western=20
FL Panhandle with NASA SPoRT-LIS 0-40cm soil moisture percentiles=20
above the 80th percentile. The MCS propagating south from western=20
TN is likely to continue triggering additional storms this=20
afternoon and evening, likely along its remnant outflow boundary.=20
Plus, radar and surface observations show the sea breeze moving=20
inland over eastern LA, which is likely to kick-start more storms=20
this afternoon. The 12Z LIX sounding measured a 2.11" PW and MLCAPE
approaching 2,000 J/kg. Steering flow is light, so storms will be=20
pulse-like in nature. However, given the moisture and instability=20
present, combined with the lingering sensitive soils, storms could=20
produce >3" amounts locally. This is supported by the new 12Z HREF=20
guidance showing moderate-to-high chances (50-80%) for rainfall=20
totals >3" through this evening along the I-10 corridor in=20
southeast LA. Localized flash flooding is possible this afternoon,=20 particularly in areas that drain poorly, where soils are overly=20
saturated, and in more urbanized settings.

Aside from some minor tweaks to the Marginal Risks in northern MT,
the central Plains, and west TX/eastern NM, the latest forecast=20
guidance continues to support the Marginal Risk outlooks this=20
afternoon.

Mullinax

---Previous Discussion---

...Northern Rockies...
A closed mid-level system will continue to slowly move across
Montana during the period, bringing an additional 1 to 2 inches of
rainfall. The Marginal Risk for isolated / localized flooding was
maintained with minimal adjustments based on the 00Z guidance.

...Mid-South...
Early morning MCS across eastern Kansas and Missouri is expected
to continue to move east/southeast through this morning toward the
TN Valley and Mid-South. Forward propagation after 12Z should
overall limit widespread heavy rainfall, but some elements may
locally train/repeat over the same area bringing a risk of flash
flooding, particularly early in the period across eastern Missouri.
While that activity is likely to wane by late morning, additional
thunderstorms are expected to fire up along remnant outflow
boundaries to the south and west across Mississippi and Alabama.
Pockets of 1-2" in a short duration may result in isolated flooding,
with the overall threat maintained at the Marginal Risk level.

...Central Plains...
Broad upper level forcing across the region along with modest
southeasterly low level flow will bring isolated to scattered
diurnally driven convection today across the High Plains that will
gradually track eastward through south central Nebraska and western
to central Kansas into this evening and overnight. The Marginal
Risk was maintained with a few adjustments based on the latest
model guidance.

...West Texas into New Mexico...
Modest forcing for ascent across the region combined with low level southeasterly flow will bring westward Gulf moisture. Diurnal
convection is expected across the Davis and Sacramento Mtns. Based
on the 00Z hi-res models, some of this convection may spread away
from the terrain, but overall expected to be isolated in coverage
with a localized flash flood risk today.


Taylor


Day 2
Valid 12Z Tue Jun 02 2026 - 12Z Wed Jun 03 2026

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL ACROSS PORTIONS OF
WEST TEXAS INTO NEW MEXICO...

...West Texas into New Mexico...
By Tuesday, the latest model guidance suggests greater moisture
will expand westward toward the region (compared to today) with PW
anomalies approaching 1.5 to 2 std deviations above normal. Another
round of terrain driven convection is expected that spreads east
across the area. Overall, pockets of 1 to 2 inches are possible
with resulting isolated/scattered flash flooding, particularly for
any sensitive locations such as burn scars and steeper terrain.

...Great Plains...
Large scale forcing for ascent across the High Plains will work
with an increasing amount of low level moisture to produce several
clusters of thunderstorms during the period capable of producing
heavy rainfall - one area of concern is across eastern to central
Kansas where the latest guidance has pointed toward the potential
for several repeating clusters of intense rain rates. Some of this
additional rainfall may fall on areas expected to see heavy
rainfall today. A second area of concern is the Northern Plains
where there is likely to be better forcing with the proximity to
the mid/upper level feature. Here, moisture isn't as high and storm
motions may be faster, but potential exists for intense rain rates
and locally heavy rainfall. Both of these areas (Dakotas and
western/central KS) may need upgrades to Slight Risk if trends
continue with future model cycles but for now, have maintained the
Marginal given some of the uncertainty heading into Tuesday.

...North Florida through the Gulf Coast...
A cold front will slowly advance southward across the region during
the day Tuesday, with copious amounts of moisture pooling along and
ahead of it. Thunderstorms are likely to develop, particularly
focused on the Florida Panhandle to northeast Florida where the
latest guidance points to the potential of 1-3" locally. Localized
/ isolated flash flooding will be possible due to the expected
intense rain rates and overall slower storm motions.

Taylor


Day 3
Valid 12Z Wed Jun 03 2026 - 12Z Thu Jun 04 2026

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL OVER PORTIONS OF WEST
TEXAS...

...West Texas into New Mexico...
A greater signal exists for a stronger mid-level shortwave to move
across the southern High Plains on Wednesday. This feature,
combined with the continued relatively higher moisture in place,
should result in robust convection to develop across far eastern
New Mexico into western Texas, particularly across the TX Panhandle.
A Slight Risk was maintained for the potential of isolated to
scattered flash flooding, some of which may fall on similar areas
as Tuesday.

...Great Plains...
The active pattern across the Plains is expected again on
Wednesday with a plume of relatively higher moisture extending from
Texas all the way north into the Northern Plains. Daytime
convection is expected to fire up across the Plains and then move east/southeast into the evening/overnight hours. Several organized
clusters of convection are likely with pockets of locally heavy
rainfall. For now, a broad Marginal Risk remains in place for
isolated instances of flash flooding.


Taylor


Day 1 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/94epoints.txt__;!!DZ3fjg!_4WJSzCFUpuoTXlkGPl30hfwsBgMKPZB7gW8ZyGatsA-= fSEhkN9wtd1DETA-nd_vy6FOw8y2-lJS9b8cgOnZJEqHJr4$=20
Day 2 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/98epoints.txt__;!!DZ3fjg!_4WJSzCFUpuoTXlkGPl30hfwsBgMKPZB7gW8ZyGatsA-= fSEhkN9wtd1DETA-nd_vy6FOw8y2-lJS9b8cgOnZXtDkL9I$=20
Day 3 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/99epoints.txt__;!!DZ3fjg!_4WJSzCFUpuoTXlkGPl30hfwsBgMKPZB7gW8ZyGatsA-= fSEhkN9wtd1DETA-nd_vy6FOw8y2-lJS9b8cgOnZTZldCy4$=20

=3D =3D =3D
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FOUS30 KWBC 012000
QPFERD

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
400 PM EDT Mon Jun 1 2026

Day 1
Valid 16Z Mon Jun 01 2026 - 12Z Tue Jun 02 2026

...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL OVER PORTIONS OF
THE NORTHERN ROCKIES, GREAT PLAINS, AND MID-SOUTH...

16Z Update...

...Central Gulf Coast...

The Marginal Risk area over the Mid-South was expanded southward
to the central Gulf Coast for this update. Soils remains quite
saturated in eastern LA, southern MS, southern AL, and the western
FL Panhandle with NASA SPoRT-LIS 0-40cm soil moisture percentiles
above the 80th percentile. The MCS propagating south from western
TN is likely to continue triggering additional storms this
afternoon and evening, likely along its remnant outflow boundary.
Plus, radar and surface observations show the sea breeze moving
inland over eastern LA, which is likely to kick-start more storms
this afternoon. The 12Z LIX sounding measured a 2.11" PW and MLCAPE
approaching 2,000 J/kg. Steering flow is light, so storms will be
pulse-like in nature. However, given the moisture and instability
present, combined with the lingering sensitive soils, storms could
produce >3" amounts locally. This is supported by the new 12Z HREF
guidance showing moderate-to-high chances (50-80%) for rainfall
totals >3" through this evening along the I-10 corridor in
southeast LA. Localized flash flooding is possible this afternoon,
particularly in areas that drain poorly, where soils are overly
saturated, and in more urbanized settings.

Aside from some minor tweaks to the Marginal Risks in northern MT,
the central Plains, and west TX/eastern NM, the latest forecast
guidance continues to support the Marginal Risk outlooks this
afternoon.

Mullinax

---Previous Discussion---

...Northern Rockies...
A closed mid-level system will continue to slowly move across
Montana during the period, bringing an additional 1 to 2 inches of
rainfall. The Marginal Risk for isolated / localized flooding was
maintained with minimal adjustments based on the 00Z guidance.

...Mid-South...
Early morning MCS across eastern Kansas and Missouri is expected
to continue to move east/southeast through this morning toward the
TN Valley and Mid-South. Forward propagation after 12Z should
overall limit widespread heavy rainfall, but some elements may
locally train/repeat over the same area bringing a risk of flash
flooding, particularly early in the period across eastern Missouri.
While that activity is likely to wane by late morning, additional
thunderstorms are expected to fire up along remnant outflow
boundaries to the south and west across Mississippi and Alabama.
Pockets of 1-2" in a short duration may result in isolated flooding,
with the overall threat maintained at the Marginal Risk level.

...Central Plains...
Broad upper level forcing across the region along with modest
southeasterly low level flow will bring isolated to scattered
diurnally driven convection today across the High Plains that will
gradually track eastward through south central Nebraska and western
to central Kansas into this evening and overnight. The Marginal
Risk was maintained with a few adjustments based on the latest
model guidance.

...West Texas into New Mexico...
Modest forcing for ascent across the region combined with low level southeasterly flow will bring westward Gulf moisture. Diurnal
convection is expected across the Davis and Sacramento Mtns. Based
on the 00Z hi-res models, some of this convection may spread away
from the terrain, but overall expected to be isolated in coverage
with a localized flash flood risk today.


Taylor


Day 2
Valid 12Z Tue Jun 02 2026 - 12Z Wed Jun 03 2026

...THERE ARE SLIGHT RISKS OF EXCESSIVE RAINFALL ACROSS PORTIONS OF
WEST TEXAS INTO NEW MEXICO AND NORTH DAKOTA...

20Z Update...

...North Dakota...

Guidance started coming into better agreement on the clustering of
thunderstorm activity across ND Tuesday afternoon and into Tuesday
night. A tongue of >1.2" PWs, which is above the 90th
climatological percentile, will reside over the Northern Plains
with MUCAPE >1,000 J/kg supplying plenty of instability. Various
model model members using area-averaged sounding Tuesday afternoon
show increasingly saturated profiles with within a highly sheared
environment. Thunderstorms are likely to contain mesocyclones that
enhance rainfall rates, with discrete cells initially transitioning
to more linear structures overnight as the low-level jet
strengthens across the Dakotas. 12Z HREF probabilities show
moderate-to-high chance probabilities (50-70%) for >3" of rainfall in east-central ND with the bulk of the rainfall occurring 21Z Tues and
later. FFGs may recover somewhat, but given the potential for up to
2"/hr rainfall rates in an area susceptible to those kind of
Excessive Rainfall rates, a Slight Risk was introduced in the heart
of ND this forecast cycle.=20

Elsewhere, the inherited Slight Risk in eastern NM/west TX and the
Marginals in place across the South were adjusted for the latest
WPC QPF and some 12Z CAMs. The meteorological rationale provided=20
by the overnight shift remains on track at this time.

Mullinax

---Previous Discussion---

...West Texas into New Mexico...
By Tuesday, the latest model guidance suggests greater moisture
will expand westward toward the region (compared to today) with PW
anomalies approaching 1.5 to 2 std deviations above normal. Another
round of terrain driven convection is expected that spreads east
across the area. Overall, pockets of 1 to 2 inches are possible
with resulting isolated/scattered flash flooding, particularly for
any sensitive locations such as burn scars and steeper terrain.

...Great Plains...
Large scale forcing for ascent across the High Plains will work
with an increasing amount of low level moisture to produce several
clusters of thunderstorms during the period capable of producing
heavy rainfall - one area of concern is across eastern to central
Kansas where the latest guidance has pointed toward the potential
for several repeating clusters of intense rain rates. Some of this
additional rainfall may fall on areas expected to see heavy
rainfall today. A second area of concern is the Northern Plains
where there is likely to be better forcing with the proximity to
the mid/upper level feature. Here, moisture isn't as high and storm
motions may be faster, but potential exists for intense rain rates
and locally heavy rainfall. Both of these areas (Dakotas and
western/central KS) may need upgrades to Slight Risk if trends
continue with future model cycles but for now, have maintained the
Marginal given some of the uncertainty heading into Tuesday.

...North Florida through the Gulf Coast...
A cold front will slowly advance southward across the region during
the day Tuesday, with copious amounts of moisture pooling along and
ahead of it. Thunderstorms are likely to develop, particularly
focused on the Florida Panhandle to northeast Florida where the
latest guidance points to the potential of 1-3" locally. Localized
/ isolated flash flooding will be possible due to the expected
intense rain rates and overall slower storm motions.

Taylor


Day 3
Valid 12Z Wed Jun 03 2026 - 12Z Thu Jun 04 2026

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL OVER PORTIONS OF WEST
TEXAS...

20Z Update...

Reviewing 12Z guidance, the Slight Risk in West TX and eastern NM
was expanded farther north into the TX Panhandle with WPC QPF and
several model members showing a slightly farther northward
extension of heavier rainfall totals. Otherwise, the forecast
reasoning in the previous discussion remains valid with eastern NM
into west TX most prone to flash flooding on Wednesday.

Mullinax

---Previous Discussion---

...West Texas into New Mexico...
A greater signal exists for a stronger mid-level shortwave to move
across the southern High Plains on Wednesday. This feature,
combined with the continued relatively higher moisture in place,
should result in robust convection to develop across far eastern
New Mexico into western Texas, particularly across the TX Panhandle.
A Slight Risk was maintained for the potential of isolated to
scattered flash flooding, some of which may fall on similar areas
as Tuesday.

...Great Plains...
The active pattern across the Plains is expected again on
Wednesday with a plume of relatively higher moisture extending from
Texas all the way north into the Northern Plains. Daytime
convection is expected to fire up across the Plains and then move east/southeast into the evening/overnight hours. Several organized
clusters of convection are likely with pockets of locally heavy
rainfall. For now, a broad Marginal Risk remains in place for
isolated instances of flash flooding.


Taylor


Day 1 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/94epoints.txt__;!!DZ3fjg!6hBqam4Oyf3WWKj0Kz6NeBFu5lw5r93LUY0z0-JNBY1m= E-BYou0SmX2zL2cD0S0lYIsNHLt-NpVeTKYmwVYJFhvCEAI$=20
Day 2 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/98epoints.txt__;!!DZ3fjg!6hBqam4Oyf3WWKj0Kz6NeBFu5lw5r93LUY0z0-JNBY1m= E-BYou0SmX2zL2cD0S0lYIsNHLt-NpVeTKYmwVYJO9TxD6Y$=20
Day 3 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/99epoints.txt__;!!DZ3fjg!6hBqam4Oyf3WWKj0Kz6NeBFu5lw5r93LUY0z0-JNBY1m= E-BYou0SmX2zL2cD0S0lYIsNHLt-NpVeTKYmwVYJv1CM2C0$=20

=3D =3D =3D
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FOUS30 KWBC 020058
QPFERD

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
858 PM EDT Mon Jun 1 2026

Day 1
Valid 01Z Tue Jun 02 2026 - 12Z Tue Jun 02 2026

...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL OVER PORTIONS OF
THE NORTHERN ROCKIES, GREAT PLAINS, MID-SOUTH AND SOUTHEAST...

We will maintain the Marginal risk areas with this update. The=20
most organized convection overnight will likely be across KS and=20
NE as upscale convective growth into one or two MCSs seems likely.=20
Slow supercell movement has initially resulted in heavy rainfall=20
totals over southwest KS, although do generally expect to see some=20
increased forward motion off to the east with time as things grow=20
upscale. Organized convection will also move across NE through the=20
overnight hours. Both areas should see an eastward movement of=20
activity helping limit overall duration...although some=20
backbuilding will be possible. Overall expect the flash flood risk
to remain isolated, but localized flood impacts are probable.

Convection over portions of AR/LA/MS/AL should persist a bit=20
longer into the night than typically supported diurnally as quite=20
a bit of instability remains to go along with a few weak boundaries
and a shortwave over the lower MS Valley. Generally expect this=20
activity to be moving, although cell mergers could continue to=20
result in a localized flash flood risk.

The coverage of convection is decreasing over southeast NM and west
TX, but a few stronger cells may persist for a few more hours and
result in an isolated flash flood risk.

Not really any flash flood threat over MT, but continued=20
stratiform rain over saturated ground may continue to result in=20
some minor areal flooding.

Added a small Marginal to portions of SC and adjacent GA where some
locally heavy convection is occurring, and we should see some=20
additional development over the next few hours. An axis of=20
enhanced low level convergence, combined with MLCAPE over 1000=20
j/kg and PWs around 1.8" to 1.9", will support locally heavy rates
and an isolated flash flood risk where any cell mergers occur.

Chenard


Day 2
Valid 12Z Tue Jun 02 2026 - 12Z Wed Jun 03 2026

...THERE ARE SLIGHT RISKS OF EXCESSIVE RAINFALL ACROSS PORTIONS OF
WEST TEXAS INTO NEW MEXICO AND NORTH DAKOTA...

20Z Update...

...North Dakota...

Guidance started coming into better agreement on the clustering of
thunderstorm activity across ND Tuesday afternoon and into Tuesday
night. A tongue of >1.2" PWs, which is above the 90th
climatological percentile, will reside over the Northern Plains
with MUCAPE >1,000 J/kg supplying plenty of instability. Various
model model members using area-averaged sounding Tuesday afternoon
show increasingly saturated profiles with within a highly sheared
environment. Thunderstorms are likely to contain mesocyclones that
enhance rainfall rates, with discrete cells initially transitioning
to more linear structures overnight as the low-level jet
strengthens across the Dakotas. 12Z HREF probabilities show
moderate-to-high chance probabilities (50-70%) for >3" of rainfall in east-central ND with the bulk of the rainfall occurring 21Z Tues and
later. FFGs may recover somewhat, but given the potential for up to
2"/hr rainfall rates in an area susceptible to those kind of
Excessive Rainfall rates, a Slight Risk was introduced in the heart
of ND this forecast cycle.

Elsewhere, the inherited Slight Risk in eastern NM/west TX and the
Marginals in place across the South were adjusted for the latest
WPC QPF and some 12Z CAMs. The meteorological rationale provided
by the overnight shift remains on track at this time.

Mullinax

---Previous Discussion---

...West Texas into New Mexico...
By Tuesday, the latest model guidance suggests greater moisture
will expand westward toward the region (compared to today) with PW
anomalies approaching 1.5 to 2 std deviations above normal. Another
round of terrain driven convection is expected that spreads east
across the area. Overall, pockets of 1 to 2 inches are possible
with resulting isolated/scattered flash flooding, particularly for
any sensitive locations such as burn scars and steeper terrain.

...Great Plains...
Large scale forcing for ascent across the High Plains will work
with an increasing amount of low level moisture to produce several
clusters of thunderstorms during the period capable of producing
heavy rainfall - one area of concern is across eastern to central
Kansas where the latest guidance has pointed toward the potential
for several repeating clusters of intense rain rates. Some of this
additional rainfall may fall on areas expected to see heavy
rainfall today. A second area of concern is the Northern Plains
where there is likely to be better forcing with the proximity to
the mid/upper level feature. Here, moisture isn't as high and storm
motions may be faster, but potential exists for intense rain rates
and locally heavy rainfall. Both of these areas (Dakotas and
western/central KS) may need upgrades to Slight Risk if trends
continue with future model cycles but for now, have maintained the
Marginal given some of the uncertainty heading into Tuesday.

...North Florida through the Gulf Coast...
A cold front will slowly advance southward across the region during
the day Tuesday, with copious amounts of moisture pooling along and
ahead of it. Thunderstorms are likely to develop, particularly
focused on the Florida Panhandle to northeast Florida where the
latest guidance points to the potential of 1-3" locally. Localized
/ isolated flash flooding will be possible due to the expected
intense rain rates and overall slower storm motions.

Taylor


Day 3
Valid 12Z Wed Jun 03 2026 - 12Z Thu Jun 04 2026

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL OVER PORTIONS OF WEST
TEXAS...

20Z Update...

Reviewing 12Z guidance, the Slight Risk in West TX and eastern NM
was expanded farther north into the TX Panhandle with WPC QPF and
several model members showing a slightly farther northward
extension of heavier rainfall totals. Otherwise, the forecast
reasoning in the previous discussion remains valid with eastern NM
into west TX most prone to flash flooding on Wednesday.

Mullinax

---Previous Discussion---

...West Texas into New Mexico...
A greater signal exists for a stronger mid-level shortwave to move
across the southern High Plains on Wednesday. This feature,
combined with the continued relatively higher moisture in place,
should result in robust convection to develop across far eastern
New Mexico into western Texas, particularly across the TX Panhandle.
A Slight Risk was maintained for the potential of isolated to
scattered flash flooding, some of which may fall on similar areas
as Tuesday.

...Great Plains...
The active pattern across the Plains is expected again on
Wednesday with a plume of relatively higher moisture extending from
Texas all the way north into the Northern Plains. Daytime
convection is expected to fire up across the Plains and then move east/southeast into the evening/overnight hours. Several organized
clusters of convection are likely with pockets of locally heavy
rainfall. For now, a broad Marginal Risk remains in place for
isolated instances of flash flooding.


Taylor


Day 1 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/94epoints.txt__;!!DZ3fjg!-r_xv5Bug02gOzVJFkI6nGflap0D26qRPGMuNdV2_y9_= dLIYAELaoXnUN6xGgrTqnmE5mqNOtYSnCeChUgMw-sAlvoY$=20
Day 2 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/98epoints.txt__;!!DZ3fjg!-r_xv5Bug02gOzVJFkI6nGflap0D26qRPGMuNdV2_y9_= dLIYAELaoXnUN6xGgrTqnmE5mqNOtYSnCeChUgMw6P2VTKQ$=20
Day 3 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/99epoints.txt__;!!DZ3fjg!-r_xv5Bug02gOzVJFkI6nGflap0D26qRPGMuNdV2_y9_= dLIYAELaoXnUN6xGgrTqnmE5mqNOtYSnCeChUgMw33E7tZo$=20

=3D =3D =3D
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FOUS30 KWBC 020809
QPFERD

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
409 AM EDT Tue Jun 2 2026

Day 1
Valid 12Z Tue Jun 02 2026 - 12Z Wed Jun 03 2026

...THERE ARE SLIGHT RISKS OF EXCESSIVE RAINFALL ACROSS PORTIONS OF
WEST TEXAS INTO NEW MEXICO AND NORTH DAKOTA...

...Dakotas...
A mid to upper level system and associated surface front will=20
approach the region during the period. Ahead of it, warm moist air=20
will expand across the area with the latest guidance showing=20
precipitable water values over 1.2" and by afternoon, MUCAPE values
in excess of 1000 J/kg. Deep convection firing up in the afternoon
will initially be more discrete but is expected to evolve into=20
linear segments as the evening commences with a ramp up late in the
period possible with the developing low-level jet.=20

The 00Z HREF shows the threat for rainfall totals in excess of 3"=20
across the Slight Risk area with the greatest potential across=20
central to northeastern ND (50-80 percent). Isolated maximum hourly
rainfall totals of 2 inches will be possible. For these reasons,=20
the Slight Risk for flash flooding looks appropriate and no=20
significant changes were made for this update.=20

...Eastern New Mexico into West Texas...
Another day of isolated to scattered thunderstorms across the
region is expected as moist southeasterly flow expands further
westward into eastern New Mexico. With cool temperatures aloft
given the baggy trough in place, this should be sufficient for
greater coverage of thunderstorms, initially tied to the terrain
and then moving eastward toward the NM/TX border. Peak hourly
rainfall totals in excess of 1 inch will be possible across eastern
NM and total amounts of 1" to locally 3" will be possible. The
Slight Risk is maintained for the potential of isolated to widely
scattered flash flooding particularly for sensitive areas like=20
burn scars and steeper terrain.=20

...Gulf Coast into South Florida...
A frontal boundary analyzed early this morning across the Gulf=20
Coast is expected to slowly drop southward through the period.
Along and ahead of this feature, precipitable water values range
from 1.5" to locally over 2", which is around 1.5 std above normal
for some locations. The frontal position, combined with a favorable
upper pattern, will provide the forcing for ascent today. With
expected instability values exceeding 1500 J/kg (MUCAPE) during
peak heating, scattered to numerous showers and thunderstorms are
likely.=20

The latest HREF probabilities show potential for hourly rain=20
totals between 1-2" (up to 50 percent probability), peaking during=20
the afternoon to early evening hours. Totals of 1-3" are expected=20
within the risk area, with isolated totals of 3-5" possible in the=20 strongest/slowest thunderstorms, most likely to occur across=20
portions of FL Panhandle and across South Florida. Isolated to=20
scattered instances of flash flooding are possible given the=20
potential for intense rain rates, particularly over sensitive
locations like urban corridors.


Taylor


Day 2
Valid 12Z Wed Jun 03 2026 - 12Z Thu Jun 04 2026

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL ACROSS WEST TEXAS
INTO NEW MEXICO...

...West Texas into New Mexico...
Weak troughing aloft and the remaining relatively higher moisture
in place across the region will likely promote the development of
isolated to scattered thunderstorms again on Wednesday. The focus
for the greatest concentration of thunderstorms and rainfall=20
totals will shift a bit further east this day, likely along the=20
NM/TX border into the TX Panhandle where amounts of 1-2" with=20
isolated 3" totals likely. Isolated to scattered instances of flash
flooding will be possible.=20

...Great Plains...
An axis of higher moisture will be present ahead of an advancing
cold front moving across the Northern Plains. Moist unstable air
ahead of it will promote the development of several clusters of
thunderstorms capable of producing intense rain rates between
1-2"/hr. Isolated to scattered flash flooding is anticipated with=20
a possible upgrade to a Slight Risk needed for parts of eastern ND
and far western MN if trends continue for a more concentrated area
of thunderstorms and heavy rainfall.


Day 3
Valid 12Z Thu Jun 04 2026 - 12Z Fri Jun 05 2026

...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL ACROSS PORTIONS=20
OF THE PLAINS, UPPER MIDWEST, AND TEXAS...

...Northern Plains into the Upper Midwest...=20
Shortwave energy ejects into the Plains during the period with the
frontal boundary expected to become increasingly west to east=20
oriented as it drapes across the Upper Midwest by Thursday. This=20
will allow the moisture to pool ahead of it while also creating a=20
more favorable setup for training/repeating thunderstorms that are=20
expected to develop during the peak heating and continue into the
overnight hours with the surging low level jet. While there=20
remains uncertainty on placement (north solutions versus some that=20
are further south), the ingredients appear to be in place for heavy
rainfall from portions of the Dakotas eastward toward Minnesota.=20
For now, a Marginal Risk remains in place but an upgrade to a=20
Slight Risk may be needed in future updates if trends continue for=20
a training thunderstorm scenario.


...Plains to Texas...=20
A mid to upper level system slowly moving east out of western
Mexico will approach the region during the period. As it does so,
it will continue to pull into the area copious amounts of Gulf=20
moisture. This will bring additional rounds of thunderstorms to the
area, some of which will be locally heavy given the PWs in place=20
and potential for repeating rounds. For now, will keep a Marginal=20
Risk in place, but if greater organization of storms or confidence=20
on specific areas rises, a Slight Risk may be needed for portions=20
of western to central Texas with future updates.=20


Taylor


Day 1 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/94epoints.txt__;!!DZ3fjg!8HvHKQHbKlVjkJCTWqyVJlR9I1ZYt3MYGMW3Q2S9KaXC= 9BJVRxEB8jsw0tNMeNiWLQD33PnuofOKbCCYMJE-v6dOmdA$=20
Day 2 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/98epoints.txt__;!!DZ3fjg!8HvHKQHbKlVjkJCTWqyVJlR9I1ZYt3MYGMW3Q2S9KaXC= 9BJVRxEB8jsw0tNMeNiWLQD33PnuofOKbCCYMJE-jU_yalw$=20
Day 3 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/99epoints.txt__;!!DZ3fjg!8HvHKQHbKlVjkJCTWqyVJlR9I1ZYt3MYGMW3Q2S9KaXC= 9BJVRxEB8jsw0tNMeNiWLQD33PnuofOKbCCYMJE-cgpYe0g$=20

=3D =3D =3D
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FOUS30 KWBC 021556
QPFERD

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
1156 AM EDT Tue Jun 2 2026

Day 1
Valid 16Z Tue Jun 02 2026 - 12Z Wed Jun 03 2026

...THERE ARE SLIGHT RISKS OF EXCESSIVE RAINFALL ACROSS PORTIONS OF
WEST TEXAS INTO NEW MEXICO AND NORTH DAKOTA...

...16Z Update...

The prior forecast reasoning remains on track particularly=20
along/north of the Gulf Coast and into Florida. Elsewhere,=20
scattered to widespread storm development is expected broadly=20
across much of the Plains both ahead of an upper-low/accompanying=20
surface front over the northern Plains into the Upper Midwest as=20
well as further south with moist southeasterly upslope flow along=20
the higher terrain east of the Rockies. For the southern High=20
Plains, weak steering flow may lead to some clustering and=20 sporadic/repetitive storm movements which may increase rain totals=20
locally. The greatest storm coverage looks to focus along the=20
leading edge of higher/more anomalous moisture reaching into=20
southeastern New Mexico with potential upscale growth and movement=20
directed southeasterly along this axis. However, at least based on=20
the latest hi-res guidance, this happens to mostly overlap sandy=20
soils with higher FFGs that should help to limit impacts. The=20
greatest threat overall will likely coincide with the more=20
sensitive burn scars.=20

To the north, stronger dynamic forcing ahead of the upper-low will
contribute to some robust thunderstorm development. Southwesterly=20
flow somewhat parallel to the slowly progressing front will lead to longer-duration rainfall and help promote increased rain totals in
the 2" range, with locally higher totals of 3-4" possible. Of note
is the potential suggested in some of the hi-res guidance for an=20
initial round of storms over northeastern North Dakota preceding=20
additional development later along the front, which coincides with=20
the greatest HREF probabilities for totals higher than 3".=20

Storms may also focus along and north of an area of low pressure=20
and attendant surface boundary into the central High Plains with=20
easterly storm progression reaching into the central Plains during=20
the overnight hours. Lower instability compared to further south=20
and less dynamic forcing compared to further north leads to greater
uncertainty with both the intensity and coverage of storms, though
some locally heavier totals and at least an isolated risk of flash
flooding is noted here as well.

Putnam

...Previous Discussion...

...Dakotas...
A mid to upper level system and associated surface front will
approach the region during the period. Ahead of it, warm moist air
will expand across the area with the latest guidance showing
precipitable water values over 1.2" and by afternoon, MUCAPE values
in excess of 1000 J/kg. Deep convection firing up in the afternoon
will initially be more discrete but is expected to evolve into
linear segments as the evening commences with a ramp up late in the
period possible with the developing low-level jet.

The 00Z HREF shows the threat for rainfall totals in excess of 3"
across the Slight Risk area with the greatest potential across
central to northeastern ND (50-80 percent). Isolated maximum hourly
rainfall totals of 2 inches will be possible. For these reasons,
the Slight Risk for flash flooding looks appropriate and no
significant changes were made for this update.

...Eastern New Mexico into West Texas...
Another day of isolated to scattered thunderstorms across the
region is expected as moist southeasterly flow expands further
westward into eastern New Mexico. With cool temperatures aloft
given the baggy trough in place, this should be sufficient for
greater coverage of thunderstorms, initially tied to the terrain
and then moving eastward toward the NM/TX border. Peak hourly
rainfall totals in excess of 1 inch will be possible across eastern
NM and total amounts of 1" to locally 3" will be possible. The
Slight Risk is maintained for the potential of isolated to widely
scattered flash flooding particularly for sensitive areas like
burn scars and steeper terrain.

...Gulf Coast into South Florida...
A frontal boundary analyzed early this morning across the Gulf
Coast is expected to slowly drop southward through the period.
Along and ahead of this feature, precipitable water values range
from 1.5" to locally over 2", which is around 1.5 std above normal
for some locations. The frontal position, combined with a favorable
upper pattern, will provide the forcing for ascent today. With
expected instability values exceeding 1500 J/kg (MUCAPE) during
peak heating, scattered to numerous showers and thunderstorms are
likely.

The latest HREF probabilities show potential for hourly rain
totals between 1-2" (up to 50 percent probability), peaking during
the afternoon to early evening hours. Totals of 1-3" are expected
within the risk area, with isolated totals of 3-5" possible in the strongest/slowest thunderstorms, most likely to occur across
portions of FL Panhandle and across South Florida. Isolated to
scattered instances of flash flooding are possible given the
potential for intense rain rates, particularly over sensitive
locations like urban corridors.


Taylor


Day 2
Valid 12Z Wed Jun 03 2026 - 12Z Thu Jun 04 2026

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL ACROSS WEST TEXAS
INTO NEW MEXICO...

...West Texas into New Mexico...
Weak troughing aloft and the remaining relatively higher moisture
in place across the region will likely promote the development of
isolated to scattered thunderstorms again on Wednesday. The focus
for the greatest concentration of thunderstorms and rainfall
totals will shift a bit further east this day, likely along the
NM/TX border into the TX Panhandle where amounts of 1-2" with
isolated 3" totals likely. Isolated to scattered instances of flash
flooding will be possible.

...Great Plains...
An axis of higher moisture will be present ahead of an advancing
cold front moving across the Northern Plains. Moist unstable air
ahead of it will promote the development of several clusters of
thunderstorms capable of producing intense rain rates between
1-2"/hr. Isolated to scattered flash flooding is anticipated with
a possible upgrade to a Slight Risk needed for parts of eastern ND
and far western MN if trends continue for a more concentrated area
of thunderstorms and heavy rainfall.


Day 3
Valid 12Z Thu Jun 04 2026 - 12Z Fri Jun 05 2026

...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL ACROSS PORTIONS
OF THE PLAINS, UPPER MIDWEST, AND TEXAS...

...Northern Plains into the Upper Midwest...
Shortwave energy ejects into the Plains during the period with the
frontal boundary expected to become increasingly west to east
oriented as it drapes across the Upper Midwest by Thursday. This
will allow the moisture to pool ahead of it while also creating a
more favorable setup for training/repeating thunderstorms that are
expected to develop during the peak heating and continue into the
overnight hours with the surging low level jet. While there
remains uncertainty on placement (north solutions versus some that
are further south), the ingredients appear to be in place for heavy
rainfall from portions of the Dakotas eastward toward Minnesota.
For now, a Marginal Risk remains in place but an upgrade to a
Slight Risk may be needed in future updates if trends continue for
a training thunderstorm scenario.


...Plains to Texas...
A mid to upper level system slowly moving east out of western
Mexico will approach the region during the period. As it does so,
it will continue to pull into the area copious amounts of Gulf
moisture. This will bring additional rounds of thunderstorms to the
area, some of which will be locally heavy given the PWs in place
and potential for repeating rounds. For now, will keep a Marginal
Risk in place, but if greater organization of storms or confidence
on specific areas rises, a Slight Risk may be needed for portions
of western to central Texas with future updates.


Taylor


Day 1 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/94epoints.txt__;!!DZ3fjg!5UC_unOMDE4ujCxA7FfxgI9OcTVNH1qdYFL3mSpDMRZq= _qbhEcU1s_tKED907FUJj-X-jI2F1dYt3JA4uDA78aQq1xU$=20
Day 2 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/98epoints.txt__;!!DZ3fjg!5UC_unOMDE4ujCxA7FfxgI9OcTVNH1qdYFL3mSpDMRZq= _qbhEcU1s_tKED907FUJj-X-jI2F1dYt3JA4uDA73cke1o4$=20
Day 3 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/99epoints.txt__;!!DZ3fjg!5UC_unOMDE4ujCxA7FfxgI9OcTVNH1qdYFL3mSpDMRZq= _qbhEcU1s_tKED907FUJj-X-jI2F1dYt3JA4uDA7a10nde4$=20

=3D =3D =3D
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FOUS30 KWBC 021959
QPFERD

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
359 PM EDT Tue Jun 2 2026

Day 1
Valid 16Z Tue Jun 02 2026 - 12Z Wed Jun 03 2026

...THERE ARE SLIGHT RISKS OF EXCESSIVE RAINFALL ACROSS PORTIONS OF
WEST TEXAS INTO NEW MEXICO AND NORTH DAKOTA...

...16Z Update...

The prior forecast reasoning remains on track particularly
along/north of the Gulf Coast and into Florida. Elsewhere,
scattered to widespread storm development is expected broadly
across much of the Plains both ahead of an upper-low/accompanying
surface front over the northern Plains into the Upper Midwest as
well as further south with moist southeasterly upslope flow along
the higher terrain east of the Rockies. For the southern High
Plains, weak steering flow may lead to some clustering and
sporadic/repetitive storm movements which may increase rain totals
locally. The greatest storm coverage looks to focus along the
leading edge of higher/more anomalous moisture reaching into
southeastern New Mexico with potential upscale growth and movement
directed southeasterly along this axis. However, at least based on
the latest hi-res guidance, this happens to mostly overlap sandy
soils with higher FFGs that should help to limit impacts. The
greatest threat overall will likely coincide with the more
sensitive burn scars.

To the north, stronger dynamic forcing ahead of the upper-low will
contribute to some robust thunderstorm development. Southwesterly
flow somewhat parallel to the slowly progressing front will lead to longer-duration rainfall and help promote increased rain totals in
the 2" range, with locally higher totals of 3-4" possible. Of note
is the potential suggested in some of the hi-res guidance for an
initial round of storms over northeastern North Dakota preceding
additional development later along the front, which coincides with
the greatest HREF probabilities for totals higher than 3".

Storms may also focus along and north of an area of low pressure
and attendant surface boundary into the central High Plains with
easterly storm progression reaching into the central Plains during
the overnight hours. Lower instability compared to further south
and less dynamic forcing compared to further north leads to greater
uncertainty with both the intensity and coverage of storms, though
some locally heavier totals and at least an isolated risk of flash
flooding is noted here as well.

Putnam

...Previous Discussion...

...Dakotas...
A mid to upper level system and associated surface front will
approach the region during the period. Ahead of it, warm moist air
will expand across the area with the latest guidance showing
precipitable water values over 1.2" and by afternoon, MUCAPE values
in excess of 1000 J/kg. Deep convection firing up in the afternoon
will initially be more discrete but is expected to evolve into
linear segments as the evening commences with a ramp up late in the
period possible with the developing low-level jet.

The 00Z HREF shows the threat for rainfall totals in excess of 3"
across the Slight Risk area with the greatest potential across
central to northeastern ND (50-80 percent). Isolated maximum hourly
rainfall totals of 2 inches will be possible. For these reasons,
the Slight Risk for flash flooding looks appropriate and no
significant changes were made for this update.

...Eastern New Mexico into West Texas...
Another day of isolated to scattered thunderstorms across the
region is expected as moist southeasterly flow expands further
westward into eastern New Mexico. With cool temperatures aloft
given the baggy trough in place, this should be sufficient for
greater coverage of thunderstorms, initially tied to the terrain
and then moving eastward toward the NM/TX border. Peak hourly
rainfall totals in excess of 1 inch will be possible across eastern
NM and total amounts of 1" to locally 3" will be possible. The
Slight Risk is maintained for the potential of isolated to widely
scattered flash flooding particularly for sensitive areas like
burn scars and steeper terrain.

...Gulf Coast into South Florida...
A frontal boundary analyzed early this morning across the Gulf
Coast is expected to slowly drop southward through the period.
Along and ahead of this feature, precipitable water values range
from 1.5" to locally over 2", which is around 1.5 std above normal
for some locations. The frontal position, combined with a favorable
upper pattern, will provide the forcing for ascent today. With
expected instability values exceeding 1500 J/kg (MUCAPE) during
peak heating, scattered to numerous showers and thunderstorms are
likely.

The latest HREF probabilities show potential for hourly rain
totals between 1-2" (up to 50 percent probability), peaking during
the afternoon to early evening hours. Totals of 1-3" are expected
within the risk area, with isolated totals of 3-5" possible in the strongest/slowest thunderstorms, most likely to occur across
portions of FL Panhandle and across South Florida. Isolated to
scattered instances of flash flooding are possible given the
potential for intense rain rates, particularly over sensitive
locations like urban corridors.


Taylor


Day 2
Valid 12Z Wed Jun 03 2026 - 12Z Thu Jun 04 2026

...THERE ARE SLIGHT RISKS OF EXCESSIVE RAINFALL ACROSS WEST TEXAS=20
INTO NEW MEXICO AND THE EASTERN DAKOTAS...


...2030Z Update...

A few changes as well as a categorical upgrade have been provided=20
for this update. First, the Slight Risk covering portions of the=20
southern High Plains has been extended northeastward to include the
eastern Texas Panhandle as well as portions of western Oklahoma.=20
The now available hi-res guidance is suggestive of locally heavy=20
rainfall totals in the 3-4" range along a north/south oriented axis
of higher moisture south of an area of low pressure and attendant=20
surface boundary. HREF probabilities of >3" are in the 25-45% range
with low-end probabilities (15%) for > 5". The hi- res guidance is
a bit more ambiguous to the southwest over west Texas and=20
southeastern New Mexico, with the greatest potential for heavy=20
rainfall similar to Tuesday across southwest Texas into=20
southeastern New Mexico where an axis of higher/more anomalous=20
moisture will reach further to the west into the higher Plains=20
terrain and ahead of the Sacramento mountains. There may ultimately
be a lull in storm coverage/intensity and attendant flash flood=20
risk between these regions where relatively lower moisture is=20
present, but have left a broad Slight Risk for now with the=20
potential to further refine the outlook with additional forecast=20 guidance.=20

Second, a Slight Risk has been introduced for portions of the=20
northern Plains covering southeastern North Dakota, northeastern=20
South Dakota, and far western Minnesota. A more focused area of=20
convection is expected ahead of a wave of low pressure along the=20
cold front with the potential for upscale growth into an organized=20 convective system. Now available hi-res guidance shows the=20
potential for totals into the 2-3"+ range with low to moderate HREF probabilities of 3"+. The one caveat is that the more progressive=20
nature of the front and subsequent convection compared to Tuesday=20
may limit rainfall duration. However, there remains the potential=20
for backbuilding convection to the southwest to compensate for the=20
faster progression of the convection particularly if the surface=20
wave helps to locally slow the front's southerly progress.

Finally, a Marginal Risk has been included for South Florida.=20
Another day of afternoon thunderstorms with the potential of=20
localized totals into the 3-5" range could lead to isolated=20
flooding concerns for urban areas.=20

Putnam

...Previous Discussion...

...West Texas into New Mexico...
Weak troughing aloft and the remaining relatively higher moisture=20
in place across the region will likely promote the development of=20
isolated to scattered thunderstorms again on Wednesday. The focus=20
for the greatest concentration of thunderstorms and rainfall totals
will shift a bit further east this day, likely along the NM/TX=20
border into the TX Panhandle where amounts of 1-2" with isolated 3"
totals likely. Isolated to scattered instances of flash flooding=20
will be possible.

...Great Plains...
An axis of higher moisture will be present ahead of an advancing=20
cold front moving across the Northern Plains. Moist unstable air=20
ahead of it will promote the development of several clusters of=20 thunderstorms capable of producing intense rain rates between=20
1-2"/hr. Isolated to scattered flash flooding is anticipated with a
possible upgrade to a Slight Risk needed for parts of eastern ND=20
and far western MN if trends continue for a more concentrated area=20
of thunderstorms and heavy rainfall.

Taylor

Day 3
Valid 12Z Thu Jun 04 2026 - 12Z Fri Jun 05 2026

...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL ACROSS PORTIONS
OF THE PLAINS, UPPER MIDWEST, AND TEXAS...

...2030Z Update...

The previous forecast remains supported by the latest model=20
guidance. There continues to be a signal for locally heavier=20
rainfall ahead of the front across portions of the northern=20
Plains/Upper Midwest potentially supportive of an upgrade to a=20
Slight Risk. However, ensemble probabilities for rainfall totals=20
greater than 1 inch remain very low. Additionally, spatial=20
disparity of heavier totals in the deterministic guidance due to=20
uncertainty of the position of the front do not provide enough=20
confidence for an upgrade at this time.=20

Putnam

...Previous Discussion...

...Northern Plains into the Upper Midwest...
Shortwave energy ejects into the Plains during the period with the
frontal boundary expected to become increasingly west to east=20
oriented as it drapes across the Upper Midwest by Thursday. This=20
will allow the moisture to pool ahead of it while also creating a=20
more favorable setup for training/repeating thunderstorms that are=20
expected to develop during the peak heating and continue into the=20
overnight hours with the surging low level jet. While there remains
uncertainty on placement (north solutions versus some that are=20
further south), the ingredients appear to be in place for heavy=20
rainfall from portions of the Dakotas eastward toward Minnesota.=20
For now, a Marginal Risk remains in place but an upgrade to a=20
Slight Risk may be needed in future updates if trends continue for=20
a training thunderstorm scenario.


...Plains to Texas...
A mid to upper level system slowly moving east out of western=20
Mexico will approach the region during the period. As it does so,=20
it will continue to pull into the area copious amounts of Gulf=20
moisture. This will bring additional rounds of thunderstorms to the
area, some of which will be locally heavy given the PWs in place=20
and potential for repeating rounds. For now, will keep a Marginal=20
Risk in place, but if greater organization of storms or confidence=20
on specific areas rises, a Slight Risk may be needed for portions=20
of western to central Texas with future updates.


Taylor


Day 1 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/94epoints.txt__;!!DZ3fjg!-HeQtqxv74UNm4fh2isYZXgizocYTk7h5hYbLJlLRKnC= xgxN4eZB_x0Q11xE-n9YamixZP8lZrfQ-2YR1b5jdVBGglI$=20
Day 2 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/98epoints.txt__;!!DZ3fjg!-HeQtqxv74UNm4fh2isYZXgizocYTk7h5hYbLJlLRKnC= xgxN4eZB_x0Q11xE-n9YamixZP8lZrfQ-2YR1b5jGkGHkIk$=20
Day 3 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/99epoints.txt__;!!DZ3fjg!-HeQtqxv74UNm4fh2isYZXgizocYTk7h5hYbLJlLRKnC= xgxN4eZB_x0Q11xE-n9YamixZP8lZrfQ-2YR1b5jFwxgWRg$=20

=3D =3D =3D
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FOUS30 KWBC 030028
QPFERD

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
828 PM EDT Tue Jun 2 2026

Day 1
Valid 01Z Wed Jun 03 2026 - 12Z Wed Jun 03 2026

...THERE ARE SLIGHT RISKS OF EXCESSIVE RAINFALL ACROSS PORTIONS OF
WEST TEXAS INTO NEW MEXICO AND THE DAKOTAS...

01Z Update: Main change from the previous D1 is the expansion of
the SLGT risk further south into SD to cover for what has been an
active afternoon and evening of heavy convection across the Black
Hills area. Multiple shortwaves will continue to eject east-
northeast out of the Front Range of WY leading to ongoing periods
of thunderstorms to impact areas across southwest WY. Several flash
flood warnings have already been issued over the region, so it
stands to say the short term hydrologic state is at a point of
favor when it comes to run off capabilities. The terrain is already
a concern in the general sense, so this only added to the threat
overnight. We will eventually see storms grow upscale and migrate
eastward as cold pool mergers eventually transition convective
modes to more multi-cell varieties, so the threat will dwindle=20
after 06-09z, however the threat will remain elevated until the=20
very end of the period which allowed for an expansion of the SLGT=20
through a large portion of SD.=20

Further south into the Southern High Plains, continued threat of
heavy convection will occur this evening as large scale forcing
will only stand to increase overnight with a rarer nocturnal
convective evolution forecast across eastern NM into the western
portion of the TX Panhandle down into parts of Southwest TX. The
main focus will reside along the Rio Grande from El Paso down to
the western Big Bend area where a robust instability maximum awaits
allowing for stronger convective episodes to materialize and likely
proceed without much in the way of forfeiting any instability in
the process after the loss of diurnal destabilization. MUCAPE
between 2000-3000 J/kg will reside between the Pecos river to the
Rio Grande with a secondary max co-located between the Upper Trans
Pecos to the Permian Basin which will align with the second area of
interest across TX/NM. Cold pool mergers and sustained thunderstorm capabilities will drive an extended period of heavy rainfall
through the above areas. The SLGT was generally maintained outside
a minor adjustment southward along the Rio Grande in Southwest TX.=20

Kleebauer


Day 2
Valid 12Z Wed Jun 03 2026 - 12Z Thu Jun 04 2026

...THERE ARE SLIGHT RISKS OF EXCESSIVE RAINFALL ACROSS WEST TEXAS
INTO NEW MEXICO AND THE EASTERN DAKOTAS...


...2030Z Update...

A few changes as well as a categorical upgrade have been provided
for this update. First, the Slight Risk covering portions of the
southern High Plains has been extended northeastward to include the
eastern Texas Panhandle as well as portions of western Oklahoma.
The now available hi-res guidance is suggestive of locally heavy
rainfall totals in the 3-4" range along a north/south oriented axis
of higher moisture south of an area of low pressure and attendant
surface boundary. HREF probabilities of >3" are in the 25-45% range
with low-end probabilities (15%) for > 5". The hi- res guidance is
a bit more ambiguous to the southwest over west Texas and
southeastern New Mexico, with the greatest potential for heavy
rainfall similar to Tuesday across southwest Texas into
southeastern New Mexico where an axis of higher/more anomalous
moisture will reach further to the west into the higher Plains
terrain and ahead of the Sacramento mountains. There may ultimately
be a lull in storm coverage/intensity and attendant flash flood
risk between these regions where relatively lower moisture is
present, but have left a broad Slight Risk for now with the
potential to further refine the outlook with additional forecast
guidance.

Second, a Slight Risk has been introduced for portions of the
northern Plains covering southeastern North Dakota, northeastern
South Dakota, and far western Minnesota. A more focused area of
convection is expected ahead of a wave of low pressure along the
cold front with the potential for upscale growth into an organized
convective system. Now available hi-res guidance shows the
potential for totals into the 2-3"+ range with low to moderate HREF probabilities of 3"+. The one caveat is that the more progressive
nature of the front and subsequent convection compared to Tuesday
may limit rainfall duration. However, there remains the potential
for backbuilding convection to the southwest to compensate for the
faster progression of the convection particularly if the surface
wave helps to locally slow the front's southerly progress.

Finally, a Marginal Risk has been included for South Florida.
Another day of afternoon thunderstorms with the potential of
localized totals into the 3-5" range could lead to isolated
flooding concerns for urban areas.

Putnam

...Previous Discussion...

...West Texas into New Mexico...
Weak troughing aloft and the remaining relatively higher moisture
in place across the region will likely promote the development of
isolated to scattered thunderstorms again on Wednesday. The focus
for the greatest concentration of thunderstorms and rainfall totals
will shift a bit further east this day, likely along the NM/TX
border into the TX Panhandle where amounts of 1-2" with isolated 3"
totals likely. Isolated to scattered instances of flash flooding
will be possible.

...Great Plains...
An axis of higher moisture will be present ahead of an advancing
cold front moving across the Northern Plains. Moist unstable air
ahead of it will promote the development of several clusters of
thunderstorms capable of producing intense rain rates between
1-2"/hr. Isolated to scattered flash flooding is anticipated with a
possible upgrade to a Slight Risk needed for parts of eastern ND
and far western MN if trends continue for a more concentrated area
of thunderstorms and heavy rainfall.

Taylor

Day 3
Valid 12Z Thu Jun 04 2026 - 12Z Fri Jun 05 2026

...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL ACROSS PORTIONS
OF THE PLAINS, UPPER MIDWEST, AND TEXAS...

...2030Z Update...

The previous forecast remains supported by the latest model
guidance. There continues to be a signal for locally heavier
rainfall ahead of the front across portions of the northern
Plains/Upper Midwest potentially supportive of an upgrade to a
Slight Risk. However, ensemble probabilities for rainfall totals
greater than 1 inch remain very low. Additionally, spatial
disparity of heavier totals in the deterministic guidance due to
uncertainty of the position of the front do not provide enough
confidence for an upgrade at this time.

Putnam

...Previous Discussion...

...Northern Plains into the Upper Midwest...
Shortwave energy ejects into the Plains during the period with the
frontal boundary expected to become increasingly west to east
oriented as it drapes across the Upper Midwest by Thursday. This
will allow the moisture to pool ahead of it while also creating a
more favorable setup for training/repeating thunderstorms that are
expected to develop during the peak heating and continue into the
overnight hours with the surging low level jet. While there remains
uncertainty on placement (north solutions versus some that are
further south), the ingredients appear to be in place for heavy
rainfall from portions of the Dakotas eastward toward Minnesota.
For now, a Marginal Risk remains in place but an upgrade to a
Slight Risk may be needed in future updates if trends continue for
a training thunderstorm scenario.


...Plains to Texas...
A mid to upper level system slowly moving east out of western
Mexico will approach the region during the period. As it does so,
it will continue to pull into the area copious amounts of Gulf
moisture. This will bring additional rounds of thunderstorms to the
area, some of which will be locally heavy given the PWs in place
and potential for repeating rounds. For now, will keep a Marginal
Risk in place, but if greater organization of storms or confidence
on specific areas rises, a Slight Risk may be needed for portions
of western to central Texas with future updates.


Taylor


Day 1 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/94epoints.txt__;!!DZ3fjg!7SbaNZPaMf-rwb5ROj9fQyQhMCjtDX1Ddy1YjdGUMpPo= GRzbERjZ3G15v97amYqT5uHGOGvQe9-1M6qJXmzSiCbOGNA$=20
Day 2 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/98epoints.txt__;!!DZ3fjg!7SbaNZPaMf-rwb5ROj9fQyQhMCjtDX1Ddy1YjdGUMpPo= GRzbERjZ3G15v97amYqT5uHGOGvQe9-1M6qJXmzS2d_cZyY$=20
Day 3 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/99epoints.txt__;!!DZ3fjg!7SbaNZPaMf-rwb5ROj9fQyQhMCjtDX1Ddy1YjdGUMpPo= GRzbERjZ3G15v97amYqT5uHGOGvQe9-1M6qJXmzShL9FGFA$=20

=3D =3D =3D
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FOUS30 KWBC 030801
QPFERD

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
401 AM EDT Wed Jun 3 2026

Day 1
Valid 12Z Wed Jun 03 2026 - 12Z Thu Jun 04 2026

...THERE ARE SLIGHT RISKS OF EXCESSIVE RAINFALL ACROSS PORTIONS OF
THE NORTHERN PLAINS AND WEST TEXAS INTO EASTERN NEW MEXICO...

...Northern Plains...
Multiple areas of convection producing heavy rainfall and intense
rainfall are expected across portions of the eastern Dakotas into
far western Minnesota during the period. This activity is tied to
an advancing cold front with an axis of anomalous moisture along
and ahead of it. While the setup isn't the most favorable for=20 training/backbuilding and generally favors more progressive storm
motions, the ingredients do support the latest HREF probabilities
for isolated totals in the 3-5" range. The Slight Risk was=20
minimally adjusted to the latest trends.=20

...Texas into Oklahoma...
A surface boundary in the vicinity of the area along with a feed=20
of Gulf moisture from the southeast will continue the unsettled=20
weather pattern. Convection is likely to be ongoing at the start of
the period across far eastern NM into western TX, capable of=20
producing locally heavy rainfall and rain rates between 1-2"/hr.=20
This activity may then subside by mid day. Convection is then=20
expected to blossom further to the northeast across the TX=20
Panhandle and west-central Oklahoma. The Slight Risk in that area=20
looks good and lines up well with the latest HREF probabilities=20
for 3 inches (50-70 percent) and 5 inches (25 percent).=20

...South Florida and the Keys...
Approaching frontal boundary and tropical moisture in place will=20
contribute to another day of higher coverage and intensity of=20
thunderstorms across portions of South Florida urban corridor. HREF probabilities are elevated for localized 3-5" totals (along with=20
hourly rain totals locally between 2-3") where thunderstorms=20
persist/repeat, so a Marginal Risk has been maintained. There is=20
some signal that the intense rain rates and heavy rainfall may=20
approach the entirety of the Keys, so have opted to expand the=20
Marginal through Key West.=20


Taylor

Day 2
Valid 12Z Thu Jun 04 2026 - 12Z Fri Jun 05 2026

...THERE ARE MARGINAL RISKS OF EXCESSIVE RAINFALL ACROSS THE=20
PLAINS TO THE UPPER MIDWEST AND SOUTH FLORIDA ...

...Plains to Upper Midwest...
The cold front is expected to set up across Minnesota into the
Plains during the period, acting as the focus for organized
convection. A ramp up in the low-level jet late in the period will
likely be the primary concern for training/repeating rounds of
heavy rainfall as daytime convection should be mainly progressive
and more discrete in nature. The deterministic guidance remains
disperse and ensemble probabilities low to provide confidence for=20
any upgrade to Slight Risk at this time, but areas from southwest=20
Minnesota into portions of Iowa and eastern South Dakota are of=20
concern. For now, the Marginal Risk was maintained and adjusted to=20
the latest trends, trimming some from the western to northern=20
boundary.=20

Further south into the Plains and Texas, the continued moist
southeasterly flow and approaching mid level system out of Mexico
will bring a greater coverage of thunderstorms and the threat of
locally heavy rainfall. Overall organization of the convection is
expected to be on the lower side, but the PW anomalies support
potential for locally intense rain rates and the Marginal Risk.=20

...South Florida...
Frontal boundary stalling in the vicinity of the area will remain
the focus for scattered to numerous showers and thunderstorms
capable of producing intense rain rates and locally heavy rainfall
over the highly urbanized corridor. The risk for Thursday shifts a
bit further south across South Florida, mainly centering across the
Miami metro.=20

Taylor


Day 3
Valid 12Z Fri Jun 05 2026 - 12Z Sat Jun 06 2026

...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL ACROSS PORTIONS
OF THE PLAINS, UPPER MIDWEST, TEXAS, AND GULF COAST...

...Upper Midwest...
Low pressure moving across the region with its associated cold
front will be the focus for thunderstorm development Friday into
Friday night with southwesterly flow bringing in an axis of
relatively higher moisture. Aspects of this setup will favor
some training/repeating thunderstorms but the overall motion will
probably lean more progressive. If the front ends up more west to
east oriented and allows for a better setup for training, portions
of the area could need an upgrade to a Slight, but confidence on
that is too low at this point.

...Texas into Gulf Coast...
The mid/upper level feature over Mexico moves into Texas during
this period, continuing another day of generally unsettled weather
and scattered to numerous showers and thunderstorms. If deeper
instability can materialized, pockets of locally heavy rainfall
will be possible due to the intense rain rates. Right now, the
latest deterministic guidance and ensemble probabilities point
toward central to south TX with greater potential.=20

Along coastal Louisiana, a surface trough interacting with the
higher moisture in place will bring a higher coverage of
thunderstorms with the potential for intense rain rates and
localized heavy rainfall.=20


Taylor


Day 1 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/94epoints.txt__;!!DZ3fjg!5aSBhE9Egj2mGpznpWFI2J0aMeF5v-BihOXl34nF-qlS= nZiKzyn0o5QfFUJ2hQQF-bYqZjbHwjqc6oylouIQfg6LB6U$=20
Day 2 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/98epoints.txt__;!!DZ3fjg!5aSBhE9Egj2mGpznpWFI2J0aMeF5v-BihOXl34nF-qlS= nZiKzyn0o5QfFUJ2hQQF-bYqZjbHwjqc6oylouIQx0XbOfY$=20
Day 3 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/99epoints.txt__;!!DZ3fjg!5aSBhE9Egj2mGpznpWFI2J0aMeF5v-BihOXl34nF-qlS= nZiKzyn0o5QfFUJ2hQQF-bYqZjbHwjqc6oylouIQBi6c7Lo$=20

=3D =3D =3D
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FOUS30 KWBC 031519
QPFERD

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
1119 AM EDT Wed Jun 3 2026

Day 1
Valid 12Z Wed Jun 03 2026 - 12Z Thu Jun 04 2026

...THERE ARE SLIGHT RISKS OF EXCESSIVE RAINFALL ACROSS PORTIONS OF
THE NORTHERN PLAINS AND WEST TEXAS INTO EASTERN NEW MEXICO...

...16Z Outlook Update...
The overall forecast philosophy is on track and minimal changes are
made based on latest convective trends.

...New Mexico/West Texas into Oklahoma...
An ongoing convective complex in west/southwest Texas near the
Transpecos was slow-moving, but persistent, and will pose a flash
flood risk across southern portions of the Slight Risk in that
area this morning. Throughout the day (especially from afternoon
onward), scattered thunderstorm activity will develop across higher
terrain of central New Mexico and migrate southeastward through the
Slight Risk area into the early overnight hours. Areas of FFG
exceedence are expected, and sensitive terrain/burn scars may also
experience impacts from nearby thunderstorms. The Slight Risk area
has been expanded slightly northwestward to address the potential
for scattered thunderstorm activity in more of central/southwest=20
New Mexico that could pose a flash flood risk. More isolated
thunderstorm activity could form across the Texas South Plains into
western Oklahoma during the day, with isolated flash flooding
possible given expected slow storm movement and 1.25 inch PW
values.

...Elsewhere...
The ongoing forecast is on track. Latest guidance (particularly
CAMs) depict heavier downpours in southwestern Florida near the
Naples/Cape Coral vicinity along with southeastern coastal areas.=20
Isolated instances of flash flooding should occur across south=20
Florida -- focused along typical sensitive low spots and urban=20
areas. The Marginal Risk area was expanded northwestward to account
for flash flood risk along the southwest Florida coast.

The Marginal and Slight Risk areas in the Dakotas/western Minnesota
is also unchanged. A fairly narrow corridor of moisture/instability
will support scattered thunderstorm activity this afternoon along
and ahead of a slow-moving surface cold front. Localized areas of
training are expected, and with FFG already low in some areas
(around 1 inch/hr), FFG exceedence could occur on a scattered
basis.=20=20

See the previous discussion below for more details.

Cook/Thompson

...Previous Discussion...

...Northern Plains...
Multiple areas of convection producing heavy rainfall and intense
rainfall are expected across portions of the eastern Dakotas into
far western Minnesota during the period. This activity is tied to
an advancing cold front with an axis of anomalous moisture along
and ahead of it. While the setup isn't the most favorable for=20 training/backbuilding and generally favors more progressive storm
motions, the ingredients do support the latest HREF probabilities
for isolated totals in the 3-5" range. The Slight Risk was=20
minimally adjusted to the latest trends.=20

...Texas into Oklahoma...
A surface boundary in the vicinity of the area along with a feed=20
of Gulf moisture from the southeast will continue the unsettled=20
weather pattern. Convection is likely to be ongoing at the start of
the period across far eastern NM into western TX, capable of=20
producing locally heavy rainfall and rain rates between 1-2"/hr.=20
This activity may then subside by mid day. Convection is then=20
expected to blossom further to the northeast across the TX=20
Panhandle and west-central Oklahoma. The Slight Risk in that area=20
looks good and lines up well with the latest HREF probabilities=20
for 3 inches (50-70 percent) and 5 inches (25 percent).=20

...South Florida and the Keys...
Approaching frontal boundary and tropical moisture in place will=20
contribute to another day of higher coverage and intensity of=20
thunderstorms across portions of South Florida urban corridor. HREF probabilities are elevated for localized 3-5" totals (along with=20
hourly rain totals locally between 2-3") where thunderstorms=20
persist/repeat, so a Marginal Risk has been maintained. There is=20
some signal that the intense rain rates and heavy rainfall may=20
approach the entirety of the Keys, so have opted to expand the=20
Marginal through Key West.=20


Taylor

Day 2
Valid 12Z Thu Jun 04 2026 - 12Z Fri Jun 05 2026

...THERE ARE MARGINAL RISKS OF EXCESSIVE RAINFALL ACROSS THE=20
PLAINS TO THE UPPER MIDWEST AND SOUTH FLORIDA ...

...Plains to Upper Midwest...
The cold front is expected to set up across Minnesota into the
Plains during the period, acting as the focus for organized
convection. A ramp up in the low-level jet late in the period will
likely be the primary concern for training/repeating rounds of
heavy rainfall as daytime convection should be mainly progressive
and more discrete in nature. The deterministic guidance remains
disperse and ensemble probabilities low to provide confidence for=20
any upgrade to Slight Risk at this time, but areas from southwest=20
Minnesota into portions of Iowa and eastern South Dakota are of=20
concern. For now, the Marginal Risk was maintained and adjusted to=20
the latest trends, trimming some from the western to northern=20
boundary.=20

Further south into the Plains and Texas, the continued moist
southeasterly flow and approaching mid level system out of Mexico
will bring a greater coverage of thunderstorms and the threat of
locally heavy rainfall. Overall organization of the convection is
expected to be on the lower side, but the PW anomalies support
potential for locally intense rain rates and the Marginal Risk.=20

...South Florida...
Frontal boundary stalling in the vicinity of the area will remain
the focus for scattered to numerous showers and thunderstorms
capable of producing intense rain rates and locally heavy rainfall
over the highly urbanized corridor. The risk for Thursday shifts a
bit further south across South Florida, mainly centering across the
Miami metro.=20

Taylor


Day 3
Valid 12Z Fri Jun 05 2026 - 12Z Sat Jun 06 2026

...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL ACROSS PORTIONS
OF THE PLAINS, UPPER MIDWEST, TEXAS, AND GULF COAST...

...Upper Midwest...
Low pressure moving across the region with its associated cold
front will be the focus for thunderstorm development Friday into
Friday night with southwesterly flow bringing in an axis of
relatively higher moisture. Aspects of this setup will favor
some training/repeating thunderstorms but the overall motion will
probably lean more progressive. If the front ends up more west to
east oriented and allows for a better setup for training, portions
of the area could need an upgrade to a Slight, but confidence on
that is too low at this point.

...Texas into Gulf Coast...
The mid/upper level feature over Mexico moves into Texas during
this period, continuing another day of generally unsettled weather
and scattered to numerous showers and thunderstorms. If deeper
instability can materialized, pockets of locally heavy rainfall
will be possible due to the intense rain rates. Right now, the
latest deterministic guidance and ensemble probabilities point
toward central to south TX with greater potential.=20

Along coastal Louisiana, a surface trough interacting with the
higher moisture in place will bring a higher coverage of
thunderstorms with the potential for intense rain rates and
localized heavy rainfall.=20


Taylor


Day 1 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/94epoints.txt__;!!DZ3fjg!_Da8cVEhdAFQz9kfcPUT6eV_9kKn9P_sAoaVyR6TOXNT= v5ePF9324pTJMCwvUsvVUXCjKwcSsBwMssSAvzBZhP0HKLw$=20
Day 2 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/98epoints.txt__;!!DZ3fjg!_Da8cVEhdAFQz9kfcPUT6eV_9kKn9P_sAoaVyR6TOXNT= v5ePF9324pTJMCwvUsvVUXCjKwcSsBwMssSAvzBZP_EoXtE$=20
Day 3 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/99epoints.txt__;!!DZ3fjg!_Da8cVEhdAFQz9kfcPUT6eV_9kKn9P_sAoaVyR6TOXNT= v5ePF9324pTJMCwvUsvVUXCjKwcSsBwMssSAvzBZ2ZfVvmI$=20

=3D =3D =3D
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FOUS30 KWBC 031902
QPFERD

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
302 PM EDT Wed Jun 3 2026

Day 1
Valid 12Z Wed Jun 03 2026 - 12Z Thu Jun 04 2026

...THERE ARE SLIGHT RISKS OF EXCESSIVE RAINFALL ACROSS PORTIONS OF
THE NORTHERN PLAINS AND WEST TEXAS INTO EASTERN NEW MEXICO...

...16Z Outlook Update...
The overall forecast philosophy is on track and minimal changes are
made based on latest convective trends.

...New Mexico/West Texas into Oklahoma...
An ongoing convective complex in west/southwest Texas near the
Transpecos was slow-moving, but persistent, and will pose a flash
flood risk across southern portions of the Slight Risk in that
area this morning. Throughout the day (especially from afternoon
onward), scattered thunderstorm activity will develop across higher
terrain of central New Mexico and migrate southeastward through the
Slight Risk area into the early overnight hours. Areas of FFG
exceedence are expected, and sensitive terrain/burn scars may also
experience impacts from nearby thunderstorms. The Slight Risk area
has been expanded slightly northwestward to address the potential
for scattered thunderstorm activity in more of central/southwest=20
New Mexico that could pose a flash flood risk. More isolated
thunderstorm activity could form across the Texas South Plains into
western Oklahoma during the day, with isolated flash flooding
possible given expected slow storm movement and 1.25 inch PW
values.

...Elsewhere...
The ongoing forecast is on track. Latest guidance (particularly
CAMs) depict heavier downpours in southwestern Florida near the
Naples/Cape Coral vicinity along with southeastern coastal areas.=20
Isolated instances of flash flooding should occur across south=20
Florida -- focused along typical sensitive low spots and urban=20
areas. The Marginal Risk area was expanded northwestward to account
for flash flood risk along the southwest Florida coast.

The Marginal and Slight Risk areas in the Dakotas/western Minnesota
is also unchanged. A fairly narrow corridor of moisture/instability
will support scattered thunderstorm activity this afternoon along
and ahead of a slow-moving surface cold front. Localized areas of
training are expected, and with FFG already low in some areas
(around 1 inch/hr), FFG exceedence could occur on a scattered
basis.=20=20

See the previous discussion below for more details.

Cook/Thompson

...Previous Discussion...

...Northern Plains...
Multiple areas of convection producing heavy rainfall and intense
rainfall are expected across portions of the eastern Dakotas into
far western Minnesota during the period. This activity is tied to
an advancing cold front with an axis of anomalous moisture along
and ahead of it. While the setup isn't the most favorable for=20 training/backbuilding and generally favors more progressive storm
motions, the ingredients do support the latest HREF probabilities
for isolated totals in the 3-5" range. The Slight Risk was=20
minimally adjusted to the latest trends.=20

...Texas into Oklahoma...
A surface boundary in the vicinity of the area along with a feed=20
of Gulf moisture from the southeast will continue the unsettled=20
weather pattern. Convection is likely to be ongoing at the start of
the period across far eastern NM into western TX, capable of=20
producing locally heavy rainfall and rain rates between 1-2"/hr.=20
This activity may then subside by mid day. Convection is then=20
expected to blossom further to the northeast across the TX=20
Panhandle and west-central Oklahoma. The Slight Risk in that area=20
looks good and lines up well with the latest HREF probabilities=20
for 3 inches (50-70 percent) and 5 inches (25 percent).=20

...South Florida and the Keys...
Approaching frontal boundary and tropical moisture in place will=20
contribute to another day of higher coverage and intensity of=20
thunderstorms across portions of South Florida urban corridor. HREF probabilities are elevated for localized 3-5" totals (along with=20
hourly rain totals locally between 2-3") where thunderstorms=20
persist/repeat, so a Marginal Risk has been maintained. There is=20
some signal that the intense rain rates and heavy rainfall may=20
approach the entirety of the Keys, so have opted to expand the=20
Marginal through Key West.=20


Taylor

Day 2
Valid 12Z Thu Jun 04 2026 - 12Z Fri Jun 05 2026

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL ACROSS PORTIONS OF
EASTERN NEBRASKA AND WESTERN IOWA...

...21Z Outlook Update...
A Slight Risk was introduced for portions of eastern Nebraska and
western Iowa for this update. Models are in general concensus that
a weak mid-level wave will track northeastward from Kansas during
the afternoon and evening hours. Convection will become scattered
to widespread across the Slight Risk area as low-level flow
increases downstream of a surface dryline and low over central
NE/KS. Some negatives are apparent in the overall flash flood
scenario, including modest/dry soil moistures and some lingering
uncertainty with respect to specific axes of heaviest rainfall.
Nevertheless, areas of 2-4 inch rainfall totals are likely --
locally higher where convective training/backbuilding can
materialize. Flash flood could occur on an isolated to scattered
basis in that regime.

Elsewhere, the Marginal Risk in eastern South Dakota has been=20
expanded northward and westward across the remainder of the state.
Scattered storms should develop in western South Dakota (where FFGs
are locally low) and migrate eastward, focusing along a surface
front in northeastern portions of the state. Lingering uncertainty
regarding the extent of convection precludes a Slight Risk upgrade
for that area in this outlook.=20

Some consideration for removal of Marginal Risk was considered for
portions of Oklahoma. Convective coverage seems to be a mitigating
factor for flash flood potential in that area. The remainder of
Marginal Risk areas were kept in place for this outlook, with
scattered thunderstorm activity expected across southern New
Mexico, west Texas, and near populated areas of southeastern
Florida.

See the previous discussion below for more details.

Cook

...Previous Discussion...

...Plains to Upper Midwest...
The cold front is expected to set up across Minnesota into the
Plains during the period, acting as the focus for organized
convection. A ramp up in the low-level jet late in the period will
likely be the primary concern for training/repeating rounds of
heavy rainfall as daytime convection should be mainly progressive
and more discrete in nature. The deterministic guidance remains
disperse and ensemble probabilities low to provide confidence for=20
any upgrade to Slight Risk at this time, but areas from southwest=20
Minnesota into portions of Iowa and eastern South Dakota are of=20
concern. For now, the Marginal Risk was maintained and adjusted to=20
the latest trends, trimming some from the western to northern=20
boundary.=20

Further south into the Plains and Texas, the continued moist
southeasterly flow and approaching mid level system out of Mexico
will bring a greater coverage of thunderstorms and the threat of
locally heavy rainfall. Overall organization of the convection is
expected to be on the lower side, but the PW anomalies support
potential for locally intense rain rates and the Marginal Risk.=20

...South Florida...
Frontal boundary stalling in the vicinity of the area will remain
the focus for scattered to numerous showers and thunderstorms
capable of producing intense rain rates and locally heavy rainfall
over the highly urbanized corridor. The risk for Thursday shifts a
bit further south across South Florida, mainly centering across the
Miami metro.=20

Taylor


Day 3
Valid 12Z Fri Jun 05 2026 - 12Z Sat Jun 06 2026

...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL ACROSS PORTIONS
OF THE PLAINS, UPPER MIDWEST, TEXAS, AND GULF COAST...

...21Z Outlook Update...
The ongoing forecast is on track with only minimal changes needed
to the Marginal Risk area across the central Gulf Coast. Weak
mid/upper troughing across the southern Rockies and Texas will
promote another round of thunderstorm activity across a large part
of Texas and southern New Mexico, with attendant flash flooding
expected due to slow storm motions and abundant moisture. A second
area of flash flood potential will exist as a disturbances moves
toward portions of southeastern Louisiana and Mississippi late in
the period, increasing rainfall potential across areas that have
already been wet over the past 1-2 weeks. Lastly, scattered
thunderstorm activity will exist ahead of a front from Iowa into
Wisconsin and vicinity, spreading 1-2 inches of rain with local
amounts reaching 4 inches. Storms in that area should be
progressive in nature due to 20-30 knot mid/upper level flow,
though localized backbuilding and mergers may increase totals
locally. Marginal Risk is maintained for this scenario, though some
parts of the region may necessitate an upgrade to Slight Risk in
later forecast cycles.

Cook

...Previous Discussion...

...Upper Midwest...
Low pressure moving across the region with its associated cold
front will be the focus for thunderstorm development Friday into
Friday night with southwesterly flow bringing in an axis of
relatively higher moisture. Aspects of this setup will favor
some training/repeating thunderstorms but the overall motion will
probably lean more progressive. If the front ends up more west to
east oriented and allows for a better setup for training, portions
of the area could need an upgrade to a Slight, but confidence on
that is too low at this point.

...Texas into Gulf Coast...
The mid/upper level feature over Mexico moves into Texas during
this period, continuing another day of generally unsettled weather
and scattered to numerous showers and thunderstorms. If deeper
instability can materialized, pockets of locally heavy rainfall
will be possible due to the intense rain rates. Right now, the
latest deterministic guidance and ensemble probabilities point
toward central to south TX with greater potential.=20

Along coastal Louisiana, a surface trough interacting with the
higher moisture in place will bring a higher coverage of
thunderstorms with the potential for intense rain rates and
localized heavy rainfall.=20


Taylor


Day 1 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/94epoints.txt__;!!DZ3fjg!9mMEv93FuKxs525EusKL522MJ7Nty5RI6wv3wzjWNvu4= UmVr7TCZ9wCbXv-7sLCzppfmhtfp2dGVZb07choss8KNuNU$=20
Day 2 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/98epoints.txt__;!!DZ3fjg!9mMEv93FuKxs525EusKL522MJ7Nty5RI6wv3wzjWNvu4= UmVr7TCZ9wCbXv-7sLCzppfmhtfp2dGVZb07chos5yETsy0$=20
Day 3 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/99epoints.txt__;!!DZ3fjg!9mMEv93FuKxs525EusKL522MJ7Nty5RI6wv3wzjWNvu4= UmVr7TCZ9wCbXv-7sLCzppfmhtfp2dGVZb07chosAKc9uVo$=20

=3D =3D =3D
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FOUS30 KWBC 040042
QPFERD

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
842 PM EDT Wed Jun 3 2026

Day 1
Valid 01Z Thu Jun 04 2026 - 12Z Thu Jun 04 2026

...THERE ARE SLIGHT RISKS OF EXCESSIVE RAINFALL ACROSS PORTIONS OF
THE NORTHERN AND SOUTHERN PLAINS, BACK INTO EASTERN NEW MEXICO...

01Z Update: Frenetic pattern will continue this evening with
multiple areas of nocturnal convection driving threats of flash
flooding across both the Northern and Southern Plains, as well as
some isolated concerns the next 6 hours over parts of the Gulf
Coast and southeastern FL.=20

Main areas of concern will continue to be the respective plains
areas with multiple shortwave perturbations and organized
convective clusters likely to drive some enhanced flash flood
scenarios over the course of the evening. Prominent instability
axis' across the Northern Plains within a narrow theta_E ridge
extending through the Missouri River basin will aid in a maturation
of convective development with the overnight period likely
correlating to a shift in multi-cell mergers and organized
thunderstorms shifting eastward as they grow upscale before
petering out once they cross the Missouri River. Progressive nature
of the cells are the main deterrent for potentially greater
impacts, but PWAT anomalies between +2 and +3 standard deviations
lend credence to a moisture rich environment capable of heavy
convective cores that would lead to widely scattered flash flood
prospects. The most aggressive CAMs have the main axis running from
northern NE up through eastern SD, aligned within that primary
theta_E ridge positioned ahead of a weak frontal boundary to the
west that will make only minor headway over the next 12 hours. The
previous SLGT risk for the Northern Plains was trimmed to account
for the reputable changes within the latest hi-res deterministic
and matching the trends on radar the past few hours. It is still
present for the SD/NE border up through eastern SD in an eastern
edge entering far western MN. For more information on this threat,
please see Mesoscale Precipitation Discussion (MPD) #0311.=20

Over the Southern High Plains, yet another round of convection over
the higher terrain of NM will likely carry eastward to some degree
leading to nocturnal thunderstorms across the eastern NM High
Plains. This threat will also trickle into the western Panhandle of
TX with a threat of locally heavy rainfall once again for areas
west of the line from Amarillo to Lubbock with the greatest
potential closer to the border near and south of I-40. Models have
been mixed with the signals for heavy rainfall this evening, a far
cry from the overwhelming signals from last evening. In any case,
the steering pattern and environmental conditioning were still
favorable for heavy rain prospects across Southwest TX up through
the High Plains leading to a continuation of the SLGT with some
scaling back on the eastern flank of the risk as convective
development and future impacts are much less of a concern as you
get west of the AMA-LUB-MAF line. A second area of concern is
currently ongoing across southwest KS into northwest OK where heavy thunderstorms are aligned south to north along a surface trough
extending away from a low positioned further northwest. This area
of thunderstorms will continue for at least the first 2-4 hours of
the period before dwindling, but will have to monitor the evolution
to see if it holds further into KS. As of this time, not
anticipating significant changes to what the hi-res have been
insinuating, but the current radar favored a maintenance of the
SLGT risk over the area with some minor expansion to encompass the
ongoing threat.=20

Isolated heavy thunderstorms are plausible across the Gulf coast
and southeast FL coast, as well for the evening period before
diminishing beyond 06z. Southeast FL could hold the threat for
longer due to frictional convergence regime in proximity to a
decaying cold front bisecting the area. Any areas within the two
zones will likely be highly isolated for flash flood prospects, but
the threat is ongoing, so maintained general continuity while
precip lingers and models maintain the threat.=20

Kleebauer
=20

Day 2
Valid 12Z Thu Jun 04 2026 - 12Z Fri Jun 05 2026

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL ACROSS PORTIONS OF
EASTERN NEBRASKA AND WESTERN IOWA...

...21Z Outlook Update...
A Slight Risk was introduced for portions of eastern Nebraska and
western Iowa for this update. Models are in general consensus that
a weak mid-level wave will track northeastward from Kansas during
the afternoon and evening hours. Convection will become scattered
to widespread across the Slight Risk area as low-level flow
increases downstream of a surface dryline and low over central
NE/KS. Some negatives are apparent in the overall flash flood
scenario, including modest/dry soil moistures and some lingering
uncertainty with respect to specific axes of heaviest rainfall.
Nevertheless, areas of 2-4 inch rainfall totals are likely --
locally higher where convective training/backbuilding can
materialize. Flash flood could occur on an isolated to scattered
basis in that regime.

Elsewhere, the Marginal Risk in eastern South Dakota has been
expanded northward and westward across the remainder of the state.
Scattered storms should develop in western South Dakota (where FFGs
are locally low) and migrate eastward, focusing along a surface
front in northeastern portions of the state. Lingering uncertainty
regarding the extent of convection precludes a Slight Risk upgrade
for that area in this outlook.

Some consideration for removal of Marginal Risk was considered for
portions of Oklahoma. Convective coverage seems to be a mitigating
factor for flash flood potential in that area. The remainder of
Marginal Risk areas were kept in place for this outlook, with
scattered thunderstorm activity expected across southern New
Mexico, west Texas, and near populated areas of southeastern
Florida.

See the previous discussion below for more details.

Cook

...Previous Discussion...

...Plains to Upper Midwest...
The cold front is expected to set up across Minnesota into the
Plains during the period, acting as the focus for organized
convection. A ramp up in the low-level jet late in the period will
likely be the primary concern for training/repeating rounds of
heavy rainfall as daytime convection should be mainly progressive
and more discrete in nature. The deterministic guidance remains
disperse and ensemble probabilities low to provide confidence for
any upgrade to Slight Risk at this time, but areas from southwest
Minnesota into portions of Iowa and eastern South Dakota are of
concern. For now, the Marginal Risk was maintained and adjusted to
the latest trends, trimming some from the western to northern
boundary.

Further south into the Plains and Texas, the continued moist
southeasterly flow and approaching mid level system out of Mexico
will bring a greater coverage of thunderstorms and the threat of
locally heavy rainfall. Overall organization of the convection is
expected to be on the lower side, but the PW anomalies support
potential for locally intense rain rates and the Marginal Risk.

...South Florida...
Frontal boundary stalling in the vicinity of the area will remain
the focus for scattered to numerous showers and thunderstorms
capable of producing intense rain rates and locally heavy rainfall
over the highly urbanized corridor. The risk for Thursday shifts a
bit further south across South Florida, mainly centering across the
Miami metro.

Taylor


Day 3
Valid 12Z Fri Jun 05 2026 - 12Z Sat Jun 06 2026

...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL ACROSS PORTIONS
OF THE PLAINS, UPPER MIDWEST, TEXAS, AND GULF COAST...

...21Z Outlook Update...
The ongoing forecast is on track with only minimal changes needed
to the Marginal Risk area across the central Gulf Coast. Weak
mid/upper troughing across the southern Rockies and Texas will
promote another round of thunderstorm activity across a large part
of Texas and southern New Mexico, with attendant flash flooding
expected due to slow storm motions and abundant moisture. A second
area of flash flood potential will exist as a disturbances moves
toward portions of southeastern Louisiana and Mississippi late in
the period, increasing rainfall potential across areas that have
already been wet over the past 1-2 weeks. Lastly, scattered
thunderstorm activity will exist ahead of a front from Iowa into
Wisconsin and vicinity, spreading 1-2 inches of rain with local
amounts reaching 4 inches. Storms in that area should be
progressive in nature due to 20-30 knot mid/upper level flow,
though localized backbuilding and mergers may increase totals
locally. Marginal Risk is maintained for this scenario, though some
parts of the region may necessitate an upgrade to Slight Risk in
later forecast cycles.

Cook

...Previous Discussion...

...Upper Midwest...
Low pressure moving across the region with its associated cold
front will be the focus for thunderstorm development Friday into
Friday night with southwesterly flow bringing in an axis of
relatively higher moisture. Aspects of this setup will favor
some training/repeating thunderstorms but the overall motion will
probably lean more progressive. If the front ends up more west to
east oriented and allows for a better setup for training, portions
of the area could need an upgrade to a Slight, but confidence on
that is too low at this point.

...Texas into Gulf Coast...
The mid/upper level feature over Mexico moves into Texas during
this period, continuing another day of generally unsettled weather
and scattered to numerous showers and thunderstorms. If deeper
instability can materialized, pockets of locally heavy rainfall
will be possible due to the intense rain rates. Right now, the
latest deterministic guidance and ensemble probabilities point
toward central to south TX with greater potential.

Along coastal Louisiana, a surface trough interacting with the
higher moisture in place will bring a higher coverage of
thunderstorms with the potential for intense rain rates and
localized heavy rainfall.


Taylor


Day 1 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/94epoints.txt__;!!DZ3fjg!5iRRROblTcZclQyQuCyLfXjW0-2ngfPb-m2dFHIw5HN-= tfDT4lllMZtA0nZ_lq-9VcMUHX410O2ErsvN4AqBjvTop1Y$=20
Day 2 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/98epoints.txt__;!!DZ3fjg!5iRRROblTcZclQyQuCyLfXjW0-2ngfPb-m2dFHIw5HN-= tfDT4lllMZtA0nZ_lq-9VcMUHX410O2ErsvN4AqBSrlLTcE$=20
Day 3 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/99epoints.txt__;!!DZ3fjg!5iRRROblTcZclQyQuCyLfXjW0-2ngfPb-m2dFHIw5HN-= tfDT4lllMZtA0nZ_lq-9VcMUHX410O2ErsvN4AqB0Yf6bA0$=20

=3D =3D =3D
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FOUS30 KWBC 040830
QPFERD

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
430 AM EDT Thu Jun 4 2026

Day 1
Valid 12Z Thu Jun 04 2026 - 12Z Fri Jun 05 2026

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL OVER A PORTION OF
THE UPPER MIDWEST...

Circulation around a broad area of high pressure over the=20
Northeast US and the Mid-Atlantic Region will keep an easterly flow
of deep moisture over Florida and and anticyclonic flow from the=20
Texas and Louisiana Gulf coast that becomes southwesterly from=20
parts of the Central Plains/Upper Midwest through much of the=20
period. An upper low over northern Mexico will help draw some of=20
that moisture westward to support the risk of locally heavy=20
rainfall there.

...Gulf Coast to Upper Midwest/Northern Plains...
With a persistent fetch of an airmass from the Gulf Coast region
into the Upper Midwest...precipitable water values increase
throughout the day...exceeding 2 inches along the Texas Gulf coast
to the ARKLATEX while increasing to 1.5 inches or more in a plume
extending into parts of Minnesota and Wisconsin. The highest
probability of heaviest rain was shown in both the operational
models and the ensembles across parts of Iowa into portions of
nearby Nebraska and Kansas as mid level height falls make their way
out of the High Plains and as surface pressures fall. Rainfall
rates of 1-2 inches per hour are possible. The 00Z runs of the HREF
and the RRFS show neighborhood probabilities of 10 to 20 percent
occurrence for 2 inch amounts in 3 hours for the 24 hour period
ending at 12Z Friday morning. Those rates could be enough to
overcome initially dry soils in parts of the area as well as be
problematic in urban areas.

Elsewhere along that corridor...there is sufficient CAPE to drive
locally intense downpours from any convection that forms. The big
problem is the relatively weak shortwave energy within the flow
will be difficult to time with much lead-time. As such...left the
Marginal Risk area pretty much in place with the expectation that
some area may well stay rain-free.

...West Texas to Eastern New Mexico...

An upper level system over Mexico will help draw some of the deeper
Gulf moisture westward...keeping a risk of locally heavy rainfall
and isolated instances of flash flooding. As previously
mentioned...the overall organization of the convection is expected
to be on the lower side, but the precipitable water anomalies and
the subtle increase in the upper level difluence near the
international border support potential for locally intense rain=20
rates and the Marginal Risk.

...South Florida...
Frontal boundary stalling in the vicinity of the area will remain
the focus for scattered to numerous showers and thunderstorms
capable of producing intense rain rates and locally heavy rainfall
over the highly urbanized corridor. The risk shifts a bit farther=20
south across South Florida compared with yesterday...mainly=20
centering across the Miami metro.

Bann

Day 2
Valid 12Z Fri Jun 05 2026 - 12Z Sat Jun 06 2026

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL ACROSS PORTIONS OF
THE UPPER MIDWEST/NORTHERN PLAINS ON FRIDAY...

...21Z Outlook Update...
The ongoing forecast remainder largely on track. The main change
was the introduction of a Slight Risk across portions of Iowa to=20
parts of nearby Wisconsin and Illinois as areas of moderate to=20
heavy rainfall lingers in the area. Elsewhere...there were only=20
minimal changes needed to the Marginal Risk areas across the=20
central Gulf Coast to New Mexico...southern Louisiana and the=20
southern Florida peninsula.

Upper Midwest...
Additional scattered thunderstorm activity is expected once again=20
ahead of a front making its way from Iowa into Wisconsin and=20
vicinity, spreading 1-2 inches of rain with local amounts reaching=20
4 inches. Storms in that area should be progressive in nature due=20
to 20-30 knot mid/upper level flow, though localized backbuilding=20
and mergers may increase totals locally.=20

The Marginal Risk surrounding the Slight Risk was largely
unchanged...although some of the territory was removed from the
northern part of Michigan now that timing of the boundary and low=20
level moisture fields have become handled better by the=20
models/ensembles.

Texas into New Mexico...
Weak mid/upper troughing across the southern Rockies and Texas=20
will promote another round of thunderstorm activity across a large=20
part of Texas and southern New Mexico, with attendant flash=20
flooding expected due to slow storm motions and abundant moisture.=20

Coastal Louisiana...
A trough of low pressure interacting with the higher moisture in=20
place will bring a higher coverage of thunderstorms with the=20
potential for intense rain rates and localized heavy rainfall.
Spaghetti plots show more ARW core members than NMMB...suggesting
that there could still be shifts in placement or QPF amounts
between now and the time the outlook verifies.

South Florida...
A stalled frontal boundary over the southern Florida peninsula=20
will continue to focus scattered to numerous afternoon and evening=20
showers and thunderstorms. Given the instability...intense rain=20
rates and locally heavy rainfall over the highly urbanized=20
corridor.

Bann

Day 3
Valid 12Z Sat Jun 06 2026 - 12Z Sun Jun 07 2026

...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL OVER PORTIONS OF
THE GREAT LAKES/OHIO VALLEY AND ACROSS THE MIDDLE GULF COAST INTO
THE SOUTHERN PLAINS...

Great Lakes/Ohio Valley...
Maintained a Marginal Risk area over portions of Ohio Valley and
nearby southern Great Lakes as a front become oriented along an
east to west axis and flow aloft is weakly forced to lift
isentropically. Maximum areal average rainfall after the start of=20
the period at 12Z Saturday generally looks to be little more than
an inch. The cumulative effect of rainfall on Days 2 and 3
suggested it was too early to entirely remove the Marginal.

Texas northward into the Southern Plains...
Little change in the overall synoptic pattern is expected with
southerly flow of moisture continuing to be drawn into parts of the
Southern Plains. Some stronger/better defined shortwave energy
within the flow aloft will promote yet another round of=20
thunderstorm activity across a large part of Texas and southern New
Mexico and extending as far north as parts of Oklahoma/Arkansas and
Kansas by late Saturday night/early Sunday morning, with attendant
flash flooding expected due to slow storm motions and abundant=20
moisture.


Bann


Day 1 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/94epoints.txt__;!!DZ3fjg!-4HsnraUhiM7hgAnsbBeclFBCDk9YX0dukNSePnZ3mPU= tia4e-aRkLx9aQU1MlKf5PQe-bAqV-Jg0WTUzqUOpS8zNF8$=20
Day 2 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/98epoints.txt__;!!DZ3fjg!-4HsnraUhiM7hgAnsbBeclFBCDk9YX0dukNSePnZ3mPU= tia4e-aRkLx9aQU1MlKf5PQe-bAqV-Jg0WTUzqUO9H-QbVQ$=20
Day 3 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/99epoints.txt__;!!DZ3fjg!-4HsnraUhiM7hgAnsbBeclFBCDk9YX0dukNSePnZ3mPU= tia4e-aRkLx9aQU1MlKf5PQe-bAqV-Jg0WTUzqUObe33IOk$=20

=3D =3D =3D
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FOUS30 KWBC 041502
QPFERD

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
1102 AM EDT Thu Jun 4 2026

Day 1
Valid 12Z Thu Jun 04 2026 - 12Z Fri Jun 05 2026

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL OVER A PORTION OF
THE UPPER MIDWEST...

...16Z Outlook Update...
The ongoing outlook is generally on track. The Slight Risk area was
expanded slightly south/southwestward across northeastern Kansas to
account for latest trends in CAMs that suggest potential for
convective training and prolonged rainfall generally along the=20
I-70 corridor from Salina to Topeka and vicinity late
today/tonight. Otherwise, one or more complexes of storms are
expected to traverse the Slight Risk area from northeastern Kansas
into Iowa from afternoon through the overnight hours, with
localized training and convective mergers expected to produce
isolated to scattered instances of flash flooding.

Elsewhere, scattered, slow-moving convection will likely result in
isolated flash flood instances especially from New Mexico/southwest
Texas thorugh southeast Texas and soutwestern Louisiana. Another
complex of storms should migrate eastward across South Dakota today
and prompt localized training/flash flood concerns across
eastern/northeastern portions of that state. Isolated/urban flash
flooding is possible across southeastern Florida as well.

See the previous discussion below for more information.

Cook

...Previous Discussion...

Circulation around a broad area of high pressure over the=20
Northeast US and the Mid-Atlantic Region will keep an easterly flow
of deep moisture over Florida and and anticyclonic flow from the=20
Texas and Louisiana Gulf coast that becomes southwesterly from=20
parts of the Central Plains/Upper Midwest through much of the=20
period. An upper low over northern Mexico will help draw some of=20
that moisture westward to support the risk of locally heavy=20
rainfall there.

...Gulf Coast to Upper Midwest/Northern Plains...
With a persistent fetch of an airmass from the Gulf Coast region
into the Upper Midwest...precipitable water values increase
throughout the day...exceeding 2 inches along the Texas Gulf coast
to the ARKLATEX while increasing to 1.5 inches or more in a plume
extending into parts of Minnesota and Wisconsin. The highest
probability of heaviest rain was shown in both the operational
models and the ensembles across parts of Iowa into portions of
nearby Nebraska and Kansas as mid level height falls make their way
out of the High Plains and as surface pressures fall. Rainfall
rates of 1-2 inches per hour are possible. The 00Z runs of the HREF
and the RRFS show neighborhood probabilities of 10 to 20 percent
occurrence for 2 inch amounts in 3 hours for the 24 hour period
ending at 12Z Friday morning. Those rates could be enough to
overcome initially dry soils in parts of the area as well as be
problematic in urban areas.

Elsewhere along that corridor...there is sufficient CAPE to drive
locally intense downpours from any convection that forms. The big
problem is the relatively weak shortwave energy within the flow
will be difficult to time with much lead-time. As such...left the
Marginal Risk area pretty much in place with the expectation that
some area may well stay rain-free.

...West Texas to Eastern New Mexico...

An upper level system over Mexico will help draw some of the deeper
Gulf moisture westward...keeping a risk of locally heavy rainfall
and isolated instances of flash flooding. As previously
mentioned...the overall organization of the convection is expected
to be on the lower side, but the precipitable water anomalies and
the subtle increase in the upper level difluence near the
international border support potential for locally intense rain=20
rates and the Marginal Risk.

...South Florida...
Frontal boundary stalling in the vicinity of the area will remain
the focus for scattered to numerous showers and thunderstorms
capable of producing intense rain rates and locally heavy rainfall
over the highly urbanized corridor. The risk shifts a bit farther=20
south across South Florida compared with yesterday...mainly=20
centering across the Miami metro.

Bann

Day 2
Valid 12Z Fri Jun 05 2026 - 12Z Sat Jun 06 2026

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL ACROSS PORTIONS OF
THE UPPER MIDWEST/NORTHERN PLAINS ON FRIDAY...

...21Z Outlook Update...
The ongoing forecast remainder largely on track. The main change
was the introduction of a Slight Risk across portions of Iowa to=20
parts of nearby Wisconsin and Illinois as areas of moderate to=20
heavy rainfall lingers in the area. Elsewhere...there were only=20
minimal changes needed to the Marginal Risk areas across the=20
central Gulf Coast to New Mexico...southern Louisiana and the=20
southern Florida peninsula.

Upper Midwest...
Additional scattered thunderstorm activity is expected once again=20
ahead of a front making its way from Iowa into Wisconsin and=20
vicinity, spreading 1-2 inches of rain with local amounts reaching=20
4 inches. Storms in that area should be progressive in nature due=20
to 20-30 knot mid/upper level flow, though localized backbuilding=20
and mergers may increase totals locally.=20

The Marginal Risk surrounding the Slight Risk was largely
unchanged...although some of the territory was removed from the
northern part of Michigan now that timing of the boundary and low=20
level moisture fields have become handled better by the=20
models/ensembles.

Texas into New Mexico...
Weak mid/upper troughing across the southern Rockies and Texas=20
will promote another round of thunderstorm activity across a large=20
part of Texas and southern New Mexico, with attendant flash=20
flooding expected due to slow storm motions and abundant moisture.=20

Coastal Louisiana...
A trough of low pressure interacting with the higher moisture in=20
place will bring a higher coverage of thunderstorms with the=20
potential for intense rain rates and localized heavy rainfall.
Spaghetti plots show more ARW core members than NMMB...suggesting
that there could still be shifts in placement or QPF amounts
between now and the time the outlook verifies.

South Florida...
A stalled frontal boundary over the southern Florida peninsula=20
will continue to focus scattered to numerous afternoon and evening=20
showers and thunderstorms. Given the instability...intense rain=20
rates and locally heavy rainfall over the highly urbanized=20
corridor.

Bann

Day 3
Valid 12Z Sat Jun 06 2026 - 12Z Sun Jun 07 2026

...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL OVER PORTIONS OF
THE GREAT LAKES/OHIO VALLEY AND ACROSS THE MIDDLE GULF COAST INTO
THE SOUTHERN PLAINS...

Great Lakes/Ohio Valley...
Maintained a Marginal Risk area over portions of Ohio Valley and
nearby southern Great Lakes as a front become oriented along an
east to west axis and flow aloft is weakly forced to lift
isentropically. Maximum areal average rainfall after the start of=20
the period at 12Z Saturday generally looks to be little more than
an inch. The cumulative effect of rainfall on Days 2 and 3
suggested it was too early to entirely remove the Marginal.

Texas northward into the Southern Plains...
Little change in the overall synoptic pattern is expected with
southerly flow of moisture continuing to be drawn into parts of the
Southern Plains. Some stronger/better defined shortwave energy
within the flow aloft will promote yet another round of=20
thunderstorm activity across a large part of Texas and southern New
Mexico and extending as far north as parts of Oklahoma/Arkansas and
Kansas by late Saturday night/early Sunday morning, with attendant
flash flooding expected due to slow storm motions and abundant=20
moisture.


Bann


Day 1 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/94epoints.txt__;!!DZ3fjg!9SlGalI2SbzK5CDttWSq-IWuDMZGMcRdNT-7TfaWh95p= 8cCb2jTnQRoE9PQ2PhW54mjaYXhU4I3j6p35UEN0kpo4OwE$=20
Day 2 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/98epoints.txt__;!!DZ3fjg!9SlGalI2SbzK5CDttWSq-IWuDMZGMcRdNT-7TfaWh95p= 8cCb2jTnQRoE9PQ2PhW54mjaYXhU4I3j6p35UEN0DxSwHYQ$=20
Day 3 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/99epoints.txt__;!!DZ3fjg!9SlGalI2SbzK5CDttWSq-IWuDMZGMcRdNT-7TfaWh95p= 8cCb2jTnQRoE9PQ2PhW54mjaYXhU4I3j6p35UEN0cgLSkXg$=20

=3D =3D =3D
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FOUS30 KWBC 041828
QPFERD

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
228 PM EDT Thu Jun 4 2026

Day 1
Valid 12Z Thu Jun 04 2026 - 12Z Fri Jun 05 2026

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL OVER A PORTION OF
THE UPPER MIDWEST...

...16Z Outlook Update...
The ongoing outlook is generally on track. The Slight Risk area was
expanded slightly south/southwestward across northeastern Kansas to
account for latest trends in CAMs that suggest potential for
convective training and prolonged rainfall generally along the=20
I-70 corridor from Salina to Topeka and vicinity late
today/tonight. Otherwise, one or more complexes of storms are
expected to traverse the Slight Risk area from northeastern Kansas
into Iowa from afternoon through the overnight hours, with
localized training and convective mergers expected to produce
isolated to scattered instances of flash flooding.

Elsewhere, scattered, slow-moving convection will likely result in
isolated flash flood instances especially from New Mexico/southwest
Texas thorugh southeast Texas and soutwestern Louisiana. Another
complex of storms should migrate eastward across South Dakota today
and prompt localized training/flash flood concerns across
eastern/northeastern portions of that state. Isolated/urban flash
flooding is possible across southeastern Florida as well.

See the previous discussion below for more information.

Cook

...Previous Discussion...

Circulation around a broad area of high pressure over the=20
Northeast US and the Mid-Atlantic Region will keep an easterly flow
of deep moisture over Florida and and anticyclonic flow from the=20
Texas and Louisiana Gulf coast that becomes southwesterly from=20
parts of the Central Plains/Upper Midwest through much of the=20
period. An upper low over northern Mexico will help draw some of=20
that moisture westward to support the risk of locally heavy=20
rainfall there.

...Gulf Coast to Upper Midwest/Northern Plains...
With a persistent fetch of an airmass from the Gulf Coast region
into the Upper Midwest...precipitable water values increase
throughout the day...exceeding 2 inches along the Texas Gulf coast
to the ARKLATEX while increasing to 1.5 inches or more in a plume
extending into parts of Minnesota and Wisconsin. The highest
probability of heaviest rain was shown in both the operational
models and the ensembles across parts of Iowa into portions of
nearby Nebraska and Kansas as mid level height falls make their way
out of the High Plains and as surface pressures fall. Rainfall
rates of 1-2 inches per hour are possible. The 00Z runs of the HREF
and the RRFS show neighborhood probabilities of 10 to 20 percent
occurrence for 2 inch amounts in 3 hours for the 24 hour period
ending at 12Z Friday morning. Those rates could be enough to
overcome initially dry soils in parts of the area as well as be
problematic in urban areas.

Elsewhere along that corridor...there is sufficient CAPE to drive
locally intense downpours from any convection that forms. The big
problem is the relatively weak shortwave energy within the flow
will be difficult to time with much lead-time. As such...left the
Marginal Risk area pretty much in place with the expectation that
some area may well stay rain-free.

...West Texas to Eastern New Mexico...

An upper level system over Mexico will help draw some of the deeper
Gulf moisture westward...keeping a risk of locally heavy rainfall
and isolated instances of flash flooding. As previously
mentioned...the overall organization of the convection is expected
to be on the lower side, but the precipitable water anomalies and
the subtle increase in the upper level difluence near the
international border support potential for locally intense rain=20
rates and the Marginal Risk.

...South Florida...
Frontal boundary stalling in the vicinity of the area will remain
the focus for scattered to numerous showers and thunderstorms
capable of producing intense rain rates and locally heavy rainfall
over the highly urbanized corridor. The risk shifts a bit farther=20
south across South Florida compared with yesterday...mainly=20
centering across the Miami metro.

Bann

Day 2
Valid 12Z Fri Jun 05 2026 - 12Z Sat Jun 06 2026

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL ACROSS PORTIONS OF
EASTERN NEBRASKA INTO THE MID-MISSISSIPPI VALLEY...

...21Z Outlook Update...

The Slight Risk in the previous D2 issuance has been shifted
southwestward and expanded slightly based on most recent model
trends. Fairly progressive convection should migrate across much of
Wisconsin and Lower Michigan in the morning/early afternoon hours.
During the latter parts of the forecast period (afternoon onward),
Additional, surface-based convection should redevelop near the
NE/IA border and migrate eastward toward the MS River/IA/IL border
region. This convection should be oriented favorably for local training/backbuilding - and some of that convection (particularly
in Iowa) could fall on wet soils from prior-day anticipated
rainfall, creating more moist ground conditions favoring excessive
runoff. The current configuration of Slight reflects most recent
model depictions of heavy rainfall risk from deep convection.

Elsewhere, the overall forecast is generally on track, with small
spatial expansions of Marginal in New Mexico to account for
potential convection in higher terrain. Scattered thunderstorms
should move slowly across the entire Marginal Risk area from
NM/west Texas eastward to southeast Texas. Some consideration of
Slight was given for the Big Country/Hill Country with a nearly
stationary mid/upper trough upstream and copious moisture content
present. Instability and convective coverage were in question=20
though and will likely be dependent on prior-day convection and the
evolution of any potential complexes from west Texas that migrate=20
through the region during the early morning hours. After collab=20
with local WFOs, decision was made to wait another model cycle=20
before reconsideration of a potential upgrade.

Though specific timing is uncertain, a disturbance over the central
Gulf will begin to migrate slowly northwestward toward southeastern
Louisiana and pose heavy rainfall potential across that area and
adjacent areas of Mississippi. Wet soils from prior rainfall will
support excessive runoff should heavier rainfall/deep convection
materialize as suggested by models.

Cook

...Previous Discussion...

Upper Midwest...
Additional scattered thunderstorm activity is expected once again=20
ahead of a front making its way from Iowa into Wisconsin and=20
vicinity, spreading 1-2 inches of rain with local amounts reaching=20
4 inches. Storms in that area should be progressive in nature due=20
to 20-30 knot mid/upper level flow, though localized backbuilding=20
and mergers may increase totals locally.=20

The Marginal Risk surrounding the Slight Risk was largely
unchanged...although some of the territory was removed from the
northern part of Michigan now that timing of the boundary and low=20
level moisture fields have become handled better by the=20
models/ensembles.

Texas into New Mexico...
Weak mid/upper troughing across the southern Rockies and Texas=20
will promote another round of thunderstorm activity across a large=20
part of Texas and southern New Mexico, with attendant flash=20
flooding expected due to slow storm motions and abundant moisture.=20

Coastal Louisiana...
A trough of low pressure interacting with the higher moisture in=20
place will bring a higher coverage of thunderstorms with the=20
potential for intense rain rates and localized heavy rainfall.
Spaghetti plots show more ARW core members than NMMB...suggesting
that there could still be shifts in placement or QPF amounts
between now and the time the outlook verifies.

South Florida...
A stalled frontal boundary over the southern Florida peninsula=20
will continue to focus scattered to numerous afternoon and evening=20
showers and thunderstorms. Given the instability...intense rain=20
rates and locally heavy rainfall over the highly urbanized=20
corridor.

Bann

Day 3
Valid 12Z Sat Jun 06 2026 - 12Z Sun Jun 07 2026

...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL OVER PORTIONS OF
THE GREAT LAKES/OHIO VALLEY AND ACROSS THE MIDDLE GULF COAST INTO
THE SOUTHERN PLAINS...

...21Z Outlook Update...

The overall forecast is on track with minimal changes made based on
latest model trends. The Slight Risk along the Upper Ohio Valley
westward to Illinois was expanded/shifted southward and westward to
account for latest model trends, which develop scattered
thunderstorm activity (likely in the form of clusters/linear
segments) across the discussion area during the afternoon and
evening. Guidance has shifted somewhat more south with precip
maxima into northern West Virginia, with more isolated thunderstorm
activity expected with westward extent into Illinois. Isolated
instances of flash flooding appear possible in this regime.

Across Texas and Oklahoma, a persistent mid-level trough will
likely continue to spawn scattered to numerous shower/thunderstorm
activity, with latest guidance depicting QPF maxima near the Red
River and into western north Texas. Much of this evolution will
depend on development and persistence of any complexes from prior-
day convection, which lends uncertainty at this timeframe. Should
trends hold, a Slight may be needed in portions of west Texas and=20
the Big Country.

Lastly, models are in general agreement that a Gulf disturbance
will reach land over southeastern Louisiana and spread areas of
heavy rainfall over Louisiana and Mississippi. Local convective training/banding may be possible depending on the organization of
the disturbance. Current trends suggest additional heavy rainfall
potential over wet/sensitive ground conditions from prior rainfall
in the area the past couple weeks. Flash flooding is possible on at
least an isolated basis.

See the previous discussion below for more information.

Cook

...Previous Discussion...

Great Lakes/Ohio Valley... Maintained a=20
Marginal Risk area over portions of Ohio Valley and nearby southern
Great Lakes as a front become oriented along an east to west axis=20
and flow aloft is weakly forced to lift isentropically. Maximum=20
areal average rainfall after the start of the period at 12Z=20
Saturday generally looks to be little more than an inch. The=20
cumulative effect of rainfall on Days 2 and 3 suggested it was too=20
early to entirely remove the Marginal.

Texas northward into the Southern Plains...
Little change in the overall synoptic pattern is expected with
southerly flow of moisture continuing to be drawn into parts of the
Southern Plains. Some stronger/better defined shortwave energy
within the flow aloft will promote yet another round of=20
thunderstorm activity across a large part of Texas and southern New
Mexico and extending as far north as parts of Oklahoma/Arkansas and
Kansas by late Saturday night/early Sunday morning, with attendant
flash flooding expected due to slow storm motions and abundant=20
moisture.


Bann


Day 1 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/94epoints.txt__;!!DZ3fjg!4txR6HPuFwpRl-0KHIB4Zx1QEeZEgMuf7bskvv4CahaJ= 75xxZotx1YK1_aPIyQIC1YNSj1zMEooGCMb7Co1nBZX3Pmg$=20
Day 2 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/98epoints.txt__;!!DZ3fjg!4txR6HPuFwpRl-0KHIB4Zx1QEeZEgMuf7bskvv4CahaJ= 75xxZotx1YK1_aPIyQIC1YNSj1zMEooGCMb7Co1nHtmpGsY$=20
Day 3 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/99epoints.txt__;!!DZ3fjg!4txR6HPuFwpRl-0KHIB4Zx1QEeZEgMuf7bskvv4CahaJ= 75xxZotx1YK1_aPIyQIC1YNSj1zMEooGCMb7Co1njP3f0fw$=20

=3D =3D =3D
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FOUS30 KWBC 050016
QPFERD

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
816 PM EDT Thu Jun 4 2026

Day 1
Valid 01Z Fri Jun 05 2026 - 12Z Fri Jun 05 2026

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL OVER A PORTION OF
THE CENTRAL PLAINS AND MIDWEST...

01Z Update: The most prominent area for flash flooding will
continue to reside across portions of the Central Plains into the
Midwest with the axis lying between northeast KS into southwestern
IA and areas in-between. Enhanced low-level convergence within
the confines of a surface trough analyzed across the region will
continue to be a driver for the heavy rainfall footprint located
within the aforementioned zone. The southwestern edge of the
convective field will likely have the greatest potential for rate
driven excessive rains as the most consequential MLCAPE resides
over eastern KS (750-1500 J/kg) compared to just ~500 J/kg further
north into IA. That said, the area where the mean flow becomes a
bit less meridional and provides a better back-building scenario
lies across the quad-state intersection between IA/MO/KS/NE, the
area where a majority of CAMs are highlighting the heaviest precip.
Cold pool mergers and outflow propagation over central IA will
likely generate quicker cell motions, thus limiting the threat for
repeated impacts and/or training compared to areas further south.
The SLGT risk exists over where the heaviest HREF mean QPF for the
rest of the forecast is noted, as well as aligning within the=20
surface trough placement that is anticipated to be a focus for the=20
heavier precip orientation/potential.=20

A MRGL risk also exists across the Northern Plains encompassing SD
to western MN. Shortwave trajectory out of the High Plains of WY=20
into SD will translate into a threat for severe thunderstorms of=20
supercell characteristics this evening which point to a potential=20
for at least isolated flash flood concerns over any areas impacted.
The cell motions will likely limit the flash flood capabilities=20
enough to not see scattered to widespread instances, but there's=20
enough of a signal to maintain the MRGL risk that was in place=20
through the initial forecast updates. This allowed for part of the=20
MRGL over the North-Central U.S. to be maintained.=20

A second MRGL risk is also maintained over southwest and west TX
where bouts of heavy thunderstorms will be possible over the
Caprock area, as well as down closer to the Big Bend. Models are
all over the place with the convective evolution in these parts,
but the ones that do produce are pretty hefty given the current
environment in place. Best chance likely occurs over the Big Bend
area down into the central RGV, stemming from a shortwave ejection
out of Mexico that could very well bring strong thunderstorms out
of the adjacent Mexican state of Coahuila. Plentiful SBCAPE with
rich deep layer moisture reside within the confines of the river
valley along the border, so the prospects for any storm to display
significant rainfall rates is higher than normal. This was enough
for a general maintenance of the MRGL risk in these areas.=20

Kleebauer
=20

Day 2
Valid 12Z Fri Jun 05 2026 - 12Z Sat Jun 06 2026

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL ACROSS PORTIONS OF
EASTERN NEBRASKA INTO THE MID-MISSISSIPPI VALLEY...

...21Z Outlook Update...

The Slight Risk in the previous D2 issuance has been shifted
southwestward and expanded slightly based on most recent model
trends. Fairly progressive convection should migrate across much of
Wisconsin and Lower Michigan in the morning/early afternoon hours.
During the latter parts of the forecast period (afternoon onward),
Additional, surface-based convection should redevelop near the
NE/IA border and migrate eastward toward the MS River/IA/IL border
region. This convection should be oriented favorably for local training/backbuilding - and some of that convection (particularly
in Iowa) could fall on wet soils from prior-day anticipated
rainfall, creating more moist ground conditions favoring excessive
runoff. The current configuration of Slight reflects most recent
model depictions of heavy rainfall risk from deep convection.

Elsewhere, the overall forecast is generally on track, with small
spatial expansions of Marginal in New Mexico to account for
potential convection in higher terrain. Scattered thunderstorms
should move slowly across the entire Marginal Risk area from
NM/west Texas eastward to southeast Texas. Some consideration of
Slight was given for the Big Country/Hill Country with a nearly
stationary mid/upper trough upstream and copious moisture content
present. Instability and convective coverage were in question
though and will likely be dependent on prior-day convection and the
evolution of any potential complexes from west Texas that migrate
through the region during the early morning hours. After collab
with local WFOs, decision was made to wait another model cycle
before reconsideration of a potential upgrade.

Though specific timing is uncertain, a disturbance over the central
Gulf will begin to migrate slowly northwestward toward southeastern
Louisiana and pose heavy rainfall potential across that area and
adjacent areas of Mississippi. Wet soils from prior rainfall will
support excessive runoff should heavier rainfall/deep convection
materialize as suggested by models.

Cook

...Previous Discussion...

Upper Midwest...
Additional scattered thunderstorm activity is expected once again
ahead of a front making its way from Iowa into Wisconsin and
vicinity, spreading 1-2 inches of rain with local amounts reaching
4 inches. Storms in that area should be progressive in nature due
to 20-30 knot mid/upper level flow, though localized backbuilding
and mergers may increase totals locally.

The Marginal Risk surrounding the Slight Risk was largely
unchanged...although some of the territory was removed from the
northern part of Michigan now that timing of the boundary and low
level moisture fields have become handled better by the
models/ensembles.

Texas into New Mexico...
Weak mid/upper troughing across the southern Rockies and Texas
will promote another round of thunderstorm activity across a large
part of Texas and southern New Mexico, with attendant flash
flooding expected due to slow storm motions and abundant moisture.

Coastal Louisiana...
A trough of low pressure interacting with the higher moisture in
place will bring a higher coverage of thunderstorms with the
potential for intense rain rates and localized heavy rainfall.
Spaghetti plots show more ARW core members than NMMB...suggesting
that there could still be shifts in placement or QPF amounts
between now and the time the outlook verifies.

Bann

Day 3
Valid 12Z Sat Jun 06 2026 - 12Z Sun Jun 07 2026

...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL OVER PORTIONS OF
THE GREAT LAKES/OHIO VALLEY AND ACROSS THE MIDDLE GULF COAST INTO
THE SOUTHERN PLAINS...

...21Z Outlook Update...

The overall forecast is on track with minimal changes made based on
latest model trends. The Slight Risk along the Upper Ohio Valley
westward to Illinois was expanded/shifted southward and westward to
account for latest model trends, which develop scattered
thunderstorm activity (likely in the form of clusters/linear
segments) across the discussion area during the afternoon and
evening. Guidance has shifted somewhat more south with precip
maxima into northern West Virginia, with more isolated thunderstorm
activity expected with westward extent into Illinois. Isolated
instances of flash flooding appear possible in this regime.

Across Texas and Oklahoma, a persistent mid-level trough will
likely continue to spawn scattered to numerous shower/thunderstorm
activity, with latest guidance depicting QPF maxima near the Red
River and into western north Texas. Much of this evolution will
depend on development and persistence of any complexes from prior-
day convection, which lends uncertainty at this timeframe. Should
trends hold, a Slight may be needed in portions of west Texas and
the Big Country.

Lastly, models are in general agreement that a Gulf disturbance
will reach land over southeastern Louisiana and spread areas of
heavy rainfall over Louisiana and Mississippi. Local convective training/banding may be possible depending on the organization of
the disturbance. Current trends suggest additional heavy rainfall
potential over wet/sensitive ground conditions from prior rainfall
in the area the past couple weeks. Flash flooding is possible on at
least an isolated basis.

See the previous discussion below for more information.

Cook

...Previous Discussion...

Great Lakes/Ohio Valley... Maintained a
Marginal Risk area over portions of Ohio Valley and nearby southern
Great Lakes as a front become oriented along an east to west axis
and flow aloft is weakly forced to lift isentropically. Maximum
areal average rainfall after the start of the period at 12Z
Saturday generally looks to be little more than an inch. The
cumulative effect of rainfall on Days 2 and 3 suggested it was too
early to entirely remove the Marginal.

Texas northward into the Southern Plains...
Little change in the overall synoptic pattern is expected with
southerly flow of moisture continuing to be drawn into parts of the
Southern Plains. Some stronger/better defined shortwave energy
within the flow aloft will promote yet another round of
thunderstorm activity across a large part of Texas and southern New
Mexico and extending as far north as parts of Oklahoma/Arkansas and
Kansas by late Saturday night/early Sunday morning, with attendant
flash flooding expected due to slow storm motions and abundant
moisture.


Bann


Day 1 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/94epoints.txt__;!!DZ3fjg!6CVpdS-YkwuvdnHjW9Dc7oKoJq5q6jtz5xYuVZ86Vv7f= riU1lBvhMt1Y5Nwofy0hyJXqGyCZNkKEvZGqIw9yY4qksuM$=20
Day 2 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/98epoints.txt__;!!DZ3fjg!6CVpdS-YkwuvdnHjW9Dc7oKoJq5q6jtz5xYuVZ86Vv7f= riU1lBvhMt1Y5Nwofy0hyJXqGyCZNkKEvZGqIw9yCCFU-BA$=20
Day 3 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/99epoints.txt__;!!DZ3fjg!6CVpdS-YkwuvdnHjW9Dc7oKoJq5q6jtz5xYuVZ86Vv7f= riU1lBvhMt1Y5Nwofy0hyJXqGyCZNkKEvZGqIw9ywZ_N99U$=20

=3D =3D =3D
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FOUS30 KWBC 050817
QPFERD

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
417 AM EDT Fri Jun 5 2026

Day 1
Valid 12Z Fri Jun 05 2026 - 12Z Sat Jun 06 2026

...THERE ARE SLIGHT RISKS OF EXCESSIVE RAINFALL ACROSS PORTIONS OF
EASTERN NEBRASKA/KANSAS INTO THE MID-MISSISSIPPI VALLEY AS WELL AS
MUCH OF TEXAS/SOUTHERN OKLAHOMA...

...Eastern Nebraska/Kansas to Mid-MS Valley...

A northern stream shortwave with multiple embedded vort maxes will
move through the Midwest Friday and provide lift for convection.
First, convection and potential for flash flooding looks to be
ongoing as the period begins 12Z Friday morning generally near the Iowa/Missouri and Iowa/Illinois border. This also sends
precipitation into Wisconsin and Lower Michigan in the morning to
early afternoon, but ahead of the influx of instability, so this is
a more Marginal flood threat. The next and likely stronger energy
in the shortwave, along with a cold front slowly shifting
southward, will help develop another round of storms beginning in
the afternoon and likely becoming enhanced in the evening and
overnight hours. The HREF and its members as well as the REFS show
this should be centered in southeastern Nebraska and northeastern
Kansas to southern Iowa, with periods of QPF exceeding FFG (HREF
and REFS probabilities 20-50% for FFG exceedance). A Slight Risk
remains reasonable for this activity, but upgrades are not out of
the question if training looks to overlap with the currently
ongoing (Thursday night) convection.


...Texas to Southern Oklahoma...

A compact southern stream upper low is forecast to drift from=20
northern Mexico across Texas during the Day 1 period. This lifting=20
mechanism will be paired with precipitable water anomalies in the=20
90-95th percentile in the southern Plains. There is some=20
uncertainty in magnitude of instability due to cloud cover, but=20
models show CAPE being sufficient at generally 1000-3000 J/kg, with
the low aloft helping steepen lapse rates. Scattered convection=20
that has the ingredients for flash flooding is likely to occur, so=20
went with an upgrade to a broad Slight Risk in this issuance. The=20
exact focus for the heaviest rain remains somewhat elusive, but=20
there is some signal in the CAMs for east-central Texas. Also=20
included areas to the west in the Slight, to include some of the=20
typically more sensitive/lower FFG areas in the Hill Country to=20
Concho Valley and Permian Basin. The Marginal Risk stretches back=20
into New Mexico where there are some sensitive areas like burn=20
scars.=20


...Central Gulf Coast...

A disturbance likely in the form of a trough at low levels is
forecast to drift slowly toward the central Gulf Coast,
specifically southeastern Louisiana and southern Mississippi. With
moisture anomalies over the 90th if not the 95th percentile and
sufficient instability, intense rain rates could lead to a flooding
threat in the form of a Marginal Risk. Though typically not a very
sensitive area to flash flooding, antecedent wet conditions could
enhance the potential. The back end of the trough could also lead
to heavy rain in the Florida Keys, with the HREF and REFS
neighborhood probabilities of reaching over 5 inches of rain
greater than 60 percent, but considering the possibility the
heaviest rain could be offshore and how much rain the Keys can
handle with the sandy soils, held off on any risk area.


Tate


Day 2
Valid 12Z Sat Jun 06 2026 - 12Z Sun Jun 07 2026

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL ACROSS PORTIONS OF
THE SOUTHERN PLAINS TO MISSISSIPPI VALLEY...

...Southern Plains/Mississippi Valley...

The meteorological setup on Saturday across the south-central U.S.
will be similar to Friday, through with the compact upper low
gradually tracking north across the southern half of the Plains.
The continued enhanced moisture and instability will yield an
environment favorable for convection with intense rain rates
causing flash flooding concerns. Areas farther north into Oklahoma
should see stronger forcing, while the low level jet could be
maximized farther south into Texas. Thus covered all this area with
a Slight Risk. REFS probabilities (which extend through the Day 2
period) show scattered instances of QPF potentially exceeding FFG.
Smaller scale boundaries leftover from thunderstorms on previous=20
days could provide areas of focus that would likely be unclear=20
before the near term.


...Central Gulf Coast...

By Saturday the surface/low level trough mentioned in the Day 1
discussion should reach the central Gulf Coast during the day, and
produce heavier QPF on land compared to Friday. Once again,
antecedent conditions in the region are not typically sensitive,
but are wetter than normal. REFS probabilities of exceeding FFG are
20-40% in southeast Louisiana, so will continue to monitor if slow storms/training are likely to cause more Slight Risk level impacts
and need an upgrade.


...Ohio Valley...

The northern stream shortwave is forecast to push through the Great
Lakes/Ohio Valley and Northeast on Saturday, with a frontal system
ahead of it. The front should lay west to east across the Ohio
Valley, so scattered storms could train and cause isolated flash
flooding. The Northeast can also expect some convection, but likely
progressive enough to limit flash flood potential to below a
Marginal. In this ERO issuance, connected the Plains and Ohio
Valley Marginal Risks together. There is some potential for storms
back into northern Missouri and vicinity, which could be very wet
after multiple rounds of convection, so wanted to cover that area.


Tate


Day 3
Valid 12Z Sun Jun 07 2026 - 12Z Mon Jun 08 2026

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL ACROSS PORTIONS OF
THE SOUTHERN/CENTRAL PLAINS TO LOWER/MIDDLE MISSISSIPPI VALLEY...

Into Sunday, southern stream energy will continue to push north=20
through the central/northern Plains and Midwest while opening up=20
into a trough. This will once again provide forcing for=20
thunderstorms in the Plains and Mississippi Valley. A low level jet
of 30-40 kt should bring instability and moisture into the region.
The best overlap of ingredients for flash flooding, supported by=20
GEFS/ECens probabilities for over an inch of rain, will likely be=20
centered over Missouri south into Arkansas and west into eastern=20
parts of Kansas and Oklahoma, so this is where the Slight Risk is=20
drawn for Day 3. Some convection could linger farther south toward=20
the Gulf Coast, which the Marginal covers. By Sunday night, a=20
northern stream trough with a strong vort max is forecast to push=20
into the northern High Plains, bringing enhanced QPF ahead of it=20
for a Marginal Risk stretching through portions of the Dakotas and=20
western Minnesota.


Tate


Day 1 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/94epoints.txt__;!!DZ3fjg!8KPVVcT5-AI7L81XWU7S_2A4HUKIbvfDFrjCpsYPX7fn= G0wtw4TrHP7pXUEZRc9-bK-5BF8k-KcGALrMUFPUxI9zz9I$=20
Day 2 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/98epoints.txt__;!!DZ3fjg!8KPVVcT5-AI7L81XWU7S_2A4HUKIbvfDFrjCpsYPX7fn= G0wtw4TrHP7pXUEZRc9-bK-5BF8k-KcGALrMUFPUqu4JHGg$=20
Day 3 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/99epoints.txt__;!!DZ3fjg!8KPVVcT5-AI7L81XWU7S_2A4HUKIbvfDFrjCpsYPX7fn= G0wtw4TrHP7pXUEZRc9-bK-5BF8k-KcGALrMUFPUQY9Uq9w$=20

=3D =3D =3D
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