ACUS02 KWNS 040558
SWODY2
SPC AC 040557

Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1257 AM CDT Mon Aug 04 2025

Valid 051200Z - 061200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE NORTHERN PLAINS...

...SUMMARY...
Thunderstorms associated with a threat for severe gusts and isolated
large hail will be possible across parts of the central and northern
Plains on Tuesday.

...Central and Northern Plains...
A mid-level shortwave trough will move into the northern Plains on
Tuesday. At the surface, a trough is forecast to sharpen during the
day across the far western Dakotas. To the east of the trough, a
moist airmass will be in place across much of the northern Plains.
By afternoon, a north-to-south axis of moderate instability is
forecast to develop to the east of the surface trough from western
Nebraska northward into the western Dakotas. Within the moist
sector, model consensus suggests that MLCAPE will peak in the 2500
to 3500 J/kg range, with the overall maximum located in western
South Dakota. Low-level convergence will likely increase near and to
the east of the surface trough, with scattered convective initiation
expected near the trough in the late afternoon. These storms should
spread eastward across west-central South Dakota and southwestern
North Dakota during the late afternoon and early evening. A severe
threat appears likely.

Forecast soundings during the late afternoon across northwestern
South Dakota have supercell wind profiles, with directional shear in
the low to mid-levels, and 35 to 40 knots of 0-6 km shear. In
addition, 700-500 mb lapse rates are forecast to be near 8 C/km.
This environment would favor isolated large hail with rotating cells
that remain discrete. A potential for severe wind gusts will also be
possible, mainly with short line segments that form within a
larger-scale cluster. The severe threat should persist into the mid
evening, and could extend southward into northern Nebraska. However,
severe threat magnitude is expected to be more isolated with
southward extent, mainly due to more limited large-scale ascent.

Further north into parts of north-central North Dakota and westward
into northeast Montana, an isolated severe threat will be possible
during the late afternoon and early evening. However, the
combination of instability and deep-layer shear is expected less
favorable than in areas to the south. This will likely keep any
severe threat localized.

..Broyles.. 08/04/2025

$$

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ACUS02 KWNS 041726
SWODY2
SPC AC 041724

Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1224 PM CDT Mon Aug 04 2025

Valid 051200Z - 061200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ON TUESDAY OVER
PARTS OF NORTH DAKOTA AND SOUTH DAKOTA...

...SUMMARY...
Thunderstorms associated with a threat for severe gusts and isolated
large hail will be possible across parts of the Dakotas on Tuesday.

...Dakotas...
A prominent shortwave trough now over northern CA/southern OR will
track northeastward and top the upper ridge on Tuesday. An
associated cold front will sag southeastward across MT and into
western ND by afternoon, promoting the development of scattered
thunderstorms. Models are in general agreement that rapid
destabilization will occur in the wake of morning clouds/precip,
with MLCAPE values of 2500+ J/kg across a broad region of the
Dakotas and northern NE. The storms that form along the front will
likely become supercellular with a risk of large hail and perhaps a
tornado or two. Activity is expected to organize upscale by early
evening, tracking across the Dakotas and northern NE with a
continued risk of damaging winds and hail.

..Hart.. 08/04/2025

$$

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ACUS02 KWNS 050557
SWODY2
SPC AC 050555

Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1255 AM CDT Tue Aug 05 2025

Valid 061200Z - 071200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE NORTH-CENTRAL U.S....

...SUMMARY...
Isolated thunderstorms associated with severe gusts and hail will be
possible across parts of the north-central U.S. on Wednesday.

...Central and Northern Plains/Upper Mississippi Valley...
An anticyclonic mid-level flow pattern with rising heights will be
in place across the north-central U.S. on Wednesday, with primarily
westerly flow over the northern Plains. At the surface, a moist
airmass will be located from Nebraska into the Dakotas. Along the
eastern edge of this moist airmass, elevated thunderstorms appear
likely to be ongoing at the start of the period. These storms are
expected to move eastward into the upper Mississippi Valley, as
moderate to strong instability develops further to the west.
Convection may initiate during the afternoon across parts of this
unstable airmass, where low-level convergence is sufficient.
However, convective coverage will likely remain very isolated, due
to a lack of large-scale ascent. Any cell that can develop into a
thunderstorm and persist could have a severe threat, due to the
instability, moderate deep-layer shear and steep low to mid-level
lapse rates. Hail and isolated severe gusts will be the primary
threats. For this outlook, will maintain a Marginal Risk due to the conditionality of the forecast, and due to the expected isolated
nature of the threat.

..Broyles.. 08/05/2025

$$

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ACUS02 KWNS 051726
SWODY2
SPC AC 051724

Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1224 PM CDT Tue Aug 05 2025

Valid 061200Z - 071200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS IN THE
NORTH-CENTRAL STATES...

...SUMMARY...
Isolated severe thunderstorms are possible across parts of the
North-Central States on Wednesday into Wednesday night.

...North-Central States...
Low probability severe potential remains evident across the region
with multiple scenarios anticipated amid fairly nebulous large-scale
ascent. Initial threat should be in the southeastern lobe across the
Lower MO Valley vicinity with potential for an ongoing MCS. As
with evolution of such an MCS but the overall signal is for a
weakening trend after 12Z. A distinct minority of guidance indicates
some potential for diurnal intensification with a remnant MCV.
Sporadic strong gusts capable of localized damage seems plausible in
the morning and perhaps into the afternoon.

Conditionally, the most favorable environment for severe should be
across the Black Hills vicinity and the NE Panhandle as convective
outflow from late D1 is pushed south into the central High Plains.
North of this outflow, a moderately supportive supercell environment
should exist. At least isolated thunderstorms should develop late
afternoon to early evening. But low-amplitude ridging between a
shortwave trough in the southern Canadian Prairies and a minor
trough in the Northwest should modulate overall coverage. Isolated
large hail and severe gusts should be anticipated into late evening.

Downstream low-level warm theta-e advection should be centered over
the Mid-MO to Upper MS Valleys on Wednesday night where a few
marginally severe storms are possible. A few strong storms may also
occur across northern MN during the afternoon, owing to trailing
influence of the southern Canadian Prairies wave. Scattered storm
coverage should be confined along the international border, but
modest mid-level lapse rates should temper convective vigor.

..Grams.. 08/05/2025

$$

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ACUS02 KWNS 060603
SWODY2
SPC AC 060601

Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
0101 AM CDT Wed Aug 06 2025

Valid 071200Z - 081200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE NORTHERN PLAINS...

...SUMMARY...
Scattered severe thunderstorms are possible Thursday afternoon and
evening across the northern Plains. Isolated very large hail and
severe gusts will be the primary threats.

...Northern Plains...
A mid-level shortwave ridge will move eastward across the northern
Plains on Thursday, as southwesterly flow becomes established across
the northern High Plains. At the surface, a low will deepen in
western South Dakota, as a cold front moves southward across western
North Dakota. To the southeast of the front, a moist and unstable
airmass will be in place across most of the northern Plains. Surface
dewpoints across this airmass should be from the mid 60s to the
lower 70s F. Ahead of the front and near the surface low, an axis of
strong instability is forecast to develop over the western Dakotas
by afternoon. Isolated convective initiation will likely take place
near the instability axis and front in the afternoon. Surface-based thunderstorms are expected to develop and move eastward across the
northern Plains during the late afternoon and evening. A severe
threat appears likely.

Forecast soundings near the instability axis at 21Z are impressive,
with MLCAPE near 5000 J/kg, 0-6 km shear around 40 knots, and
700-500 mb lapse rates near 8.5 C/km. This environment will be
favorable for supercells with large hail. Hailstones greater than 2
inches in diameter will be possible with the more intense cores. A
potential for severe gusts will also exist, with a greater threat in
the evening if cells can congeal into a short line segment. An
isolated tornado threat could also develop. Any severe threat is
expected to persist into the mid to late evening.

Further to the east-southeastward into Minnesota, and southward into
South Dakota, large-scale ascent is forecast to be weak. For this
reason, convective coverage is forecast to be limited. However,
isolated convection could initiate along zones of low-level
convergence and maximized surface heating. Any cell that could
develop and persist, could obtain an isolated threat for hail and
severe gusts.

...Montana...
A mid-level trough will move eastward across the northern Rockies on
Thursday, as the exit region of an associated jet max moves into the
northern High Plains. The western edge of a moist and unstable
airmass will likely be in place across parts of central Montana,
where model forecast suggest MLCAPE could reach the 1200 to 2500
J/kg range. Convective initiation is expected in the higher terrain
of west-central Montana, and this activity will move eastward into
the stronger instability during the evening. Additional storms
appear likely to develop in northeastern Montana during the mid to
late evening, within an upslope flow regime. In addition to the
instability, moderate to strong deep-layer shear will be in place
over the northern High Plains, mainly due to influence of the
mid-level jet. This environment should be favorable for severe
storms, with large hail and severe gusts possible in the late
afternoon and evening.

..Broyles.. 08/06/2025

$$

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ACUS02 KWNS 061729
SWODY2
SPC AC 061728

Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1228 PM CDT Wed Aug 06 2025

Valid 071200Z - 081200Z

...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS IN ND...

...SUMMARY...
Scattered severe thunderstorms are expected from mid-afternoon into
the night on Thursday. The most likely corridor is centered on North
Dakota where a few tornadoes, very large hail, and significant
severe gusts are possible.

...Northern Great Plains...
Potential for intense supercells growing upscale into a severe MCS
appears increasingly likely across ND, with a swath of scattered
supercells possible across eastern MT.

A shortwave trough will amplify across the Northwest and northern
Rockies with a seasonably vigorous impulse rotating through the
base. Downstream mid/upper ridging will shift east from the Dakotas
to MN, coincident with expansion of a stout EML characterized by
very steep lapse rates. This will overspread increasing
boundary-layer moisture from evapotranspiration across the Corn
Belt, and yield large to extreme buoyancy from southern ND to the
Mid-MO Valley by late afternoon Thursday. A strengthening baroclinic
zone along the northwest periphery of the MLCAPE plume should aid in
increasing thunderstorm development towards mid-afternoon across
western ND. Supercells capable of very large hail and a few
tornadoes are possible. The initially zonal and moderate mid/upper
flow regime will favor upscale growth. Numerous 12Z CAMs support
this scenario with indications of a severe MCS spreading eastward,
mainly across ND during the evening before gradually waning
overnight in MN. Uncertainty does exist on how far south the MCS may
build into SD and how far east the damaging wind threat will be
maintained in MN amid nocturnally increasing MLCIN.

Scattered thunderstorms will also develop across the higher terrain
of southwest/south-central MT by late afternoon to early evening.
Initial storms should generally pose a marginal severe threat until
they impinge on the western periphery of the eastern MT buoyancy
plume in the evening. Deep-layer shear profiles should support
mainly discrete supercells with some clustering possible late. A mix
of both scattered large hail and severe gusts are possible. The
eastern extent of the threat overnight into western ND and far
northwest SD should be modulated by the earlier round of
supercells/MCS.

...IL to western Upper MI...
Nebulous, low-probability severe wind/hail potential is evident
along the northeast lobe of the expansive buoyancy plume over the
central states on Thursday into Thursday night. Most guidance
indicates potential for a minor MCV or two from remnants of late D1
convection, ahead of a mid-level ridge over the Dakotas to MN. These
may focus mesoscale corridors of diurnal storm development from IL
to western Upper MI, but latitudinal uncertainty is large. In
addition, modest low-level warm theta-e advection northeast of the
Lower MO Valley to IA jet could support a corridor or two of
regenerative convection Thursday night. Amid moderate mid-level northwesterlies, sporadic strong storms are anticipated with a few
severe storms possible.

..Grams.. 08/06/2025

$$

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ACUS02 KWNS 070610
SWODY2
SPC AC 070609

Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
0109 AM CDT Thu Aug 07 2025

Valid 081200Z - 091200Z

...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE NORTHERN PLAINS AND UPPER MISSISSIPPI VALLEY...

...SUMMARY...
Scattered severe thunderstorms are expected Friday afternoon and
evening across parts of the northern Plains and upper Mississippi
Valley.

...Northern Plains/Upper Mississippi Valley...
A negatively tilted mid-level trough and an associated 50 to 60 knot
jet streak will move through the northern Plains on Friday. At the
surface, a cold front will advance eastward across the Dakotas, as
convection early in the day moves through the upper Mississippi
Valley. Ahead of the front, a moist and strongly unstable airmass
will be in place, with surface dewpoints from the upper 60s to the
mid 70s F. Low-level convergence will increase ahead of the front in
the afternoon, helping to support scattered thunderstorm
development. A cluster of strong to severe storms appears likely
across parts of the northern Plains Friday afternoon and evening.

A pristine thermodynamic environment is forecast to develop across
the northern Plains Friday afternoon. NAM forecast soundings in the
late afternoon along the instability axis near Fargo, North Dakota
have MLCAPE near 5,500 J/kg with 700-500 mb lapse rates approaching
8.5 C/km. Along the axis of instability, 0-6 km shear is forecast to
be in the 35 to 45 knot range, which should be favorable for
supercells with large hail. Hailstones of greater than 2 inches in
diameter will be possible within the stronger cores. Severe wind
gusts will also be possible.

There is some concern that convection along or ahead of the front
will remain to the west of the strongest instability. Although the
models vary concerning this scenario, the latest ECMWF has trended
toward an earlier convective initiation. The ECMWF solution, which
also develops convection further to the south, would be more
favorable for a significant severe weather event across the northern
Plains Friday afternoon and evening.

...Western Dakotas...
A post-frontal airmass will be in place across the western Dakotas
on Friday, as a cold front advances eastward away from the region.
Warming surface temperatures will contribute to weak instability by
afternoon, with MLCAPE approaching 1000 J/kg in some areas.
Large-scale ascent associated with a mid-level shortwave trough
should aid the development of a few thunderstorms during the late
afternoon and early evening. Moderate deep-layer shear and steep
mid-level lapse rates could be enough for a localized severe threat,
with hail and isolated severe wind gusts possible.

..Broyles.. 08/07/2025

$$

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ACUS02 KWNS 071731
SWODY2
SPC AC 071730

Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1230 PM CDT Thu Aug 07 2025

Valid 081200Z - 091200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS IN THE EASTERN
DAKOTAS TO WESTERN LAKE SUPERIOR...

...SUMMARY...
Scattered severe thunderstorms are possible across parts of the
Upper Midwest, mainly Friday evening into early morning Saturday.
Scattered damaging winds and large hail, along with a tornado or two
are possible.

...Synopsis...
A messy/complex setup remains evident on Friday afternoon into early
morning Saturday. In the wake of multiple MCSs on D1, guidance
consensus has trended farther east with the effective cold front by
late afternoon. This boundary should be centered on northwest MN to
eastern NE then arcing westward but pushing southward through the
central High Plains. The bulk of large-scale ascent and strong
mid/upper-level flow will lag behind this front in the northern
Great Plains, typical of amplified shortwave troughs impinging on a
ridge emanating north-northeastward from a stout anticyclone over
the Southwest.

...Dakotas to northwest WI...
Elevated convection may be ongoing at 12Z Friday and should persist
through the day across most of ND and northern SD, within a
post-frontal environment. Isolated severe hail and strong to
marginal severe gusts are possible with this activity. Strengthening
low-level convergence and ascent along/ahead of the front should
await Friday evening, with increasing storm coverage and severe
potential into Friday night. Anafrontal aspects of the synoptic
setup and near-parallel alignment of the deep-layer shear vector
with respect to the front should support a rapid transition to
cluster/linear mode. With very large MLCAPE likely prevalent ahead
of the front, potential for a QLCS producing damaging winds may
evolve overnight. Guidance differs substantially in the corridor of
where this would be favored with split signals across northern MN or
southern MN. For this outlook cycle, have broadened the level 2-SLGT
risk and will defer to later outlooks for a potential wind-driven
ENH centered somewhere in MN.

...Black Hills/NE Panhandle...
12Z CAM and ML guidance are insistent on at least an isolated large
hail scenario within the post-frontal environment characterized by
northerly surface winds. A lobe of decreasing buoyancy should linger
behind the front but will shift south with time. A few discrete
supercells are possible from mid-afternoon to early evening amid a
strong southwesterly mid-level jet. But much of the convection
should be quickly undercut and may become rather elevated, dependent
on timing of the front and low-level drying behind it. As such, have
deferred to the D1 outlooks for a mesoscale hail-driven SLGT.

..Grams.. 08/07/2025

$$

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ACUS02 KWNS 080527
SWODY2
SPC AC 080525

Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1225 AM CDT Fri Aug 08 2025

Valid 091200Z - 101200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM NORTHEAST
IOWA INTO SOUTHERN WISCONSIN...

...SUMMARY...
Isolated severe thunderstorms are possible Saturday from the Upper
Great Lakes to the Lower Missouri Valley, and across portions of the
central to southern High Plains.

...Synopsis...
An upper low will move slowly eastward across southern SK and MB,
with moderate cyclonic flow aloft moving from the northern Plains
into the upper MS Valley. As this occurs, an upper ridge over the
eastern Great Lakes will be move toward southern QB and the
Northeast. Well south of the upper low, modest westerlies aloft will
remain over the central Rockies.

At the surface, low pressure will move from southern MB into western
ON, with a boundary stalling roughly from the upper MS Valley to KS.
Ahead of this front, a moist and unstable air mass will remain with
60s and 70s F dewpoints.

...IA into WI and surrounding areas...
The leading mid/upper speed max will move across the upper MS Valley
relatively early in the day, with midlevel drying across much of MN
into western WI. Heating will occur near the stalled front, with
robust moisture leading to 2000-3000 J/kg MUCAPE by late afternoon. Complicating the forecast is the possibility of residual/midday
storms, which could potentially overturn the air mass prematurely.
However, in general, southwest low-level flow should maintain areas
of moderate instability, with a late day increase in storm coverage
and intensity. Corridors of damaging winds appear most probable,
with substantial outflow.

...Central High Plains...
Surface winds will veer to east/southeast during the day, with 50s F
dewpoints backing west toward the Front Range. Steep lapse rates
will lead to strong instability, especially from southeast CO west/northwestward. Isolated cells capable of large hail are
forecast, with perhaps a brief tornado risk during the evening as
low-level SRH increases. Capping and uncertainty in storm coverage
currently precludes higher severe probabilities.

..Jewell.. 08/08/2025

$$

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ACUS02 KWNS 081725
SWODY2
SPC AC 081723

Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1223 PM CDT Fri Aug 08 2025

Valid 091200Z - 101200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS IN PARTS OF
WI/IA/IL AND CO...

...SUMMARY...
Multiple damaging wind swaths are possible from Saturday into
Saturday night, centered on central/southern Wisconsin,
central/eastern Iowa, and northwest Illinois. Multiple rounds of
large hail are possible across eastern Colorado starting in the late
afternoon.

...Upper Great Lakes to the Lower MO Valley...
A broken linear MCS should be ongoing at 12Z Saturday, centered from
western Upper MI to northern IA. Some CAMs suggest this should decay
into multiple separate clusters during the late morning, while most
maintain at least one coherent linear band eastward. Diurnal
destabilization ahead of the large-scale outflow may support
intensification by midday into the afternoon, mainly in WI. The bulk
of strong mid-level southwesterlies will be displaced to the rear of
the composite outflow/cold front as the amplified shortwave trough
over the northern Great Plains drifts east. This will yield a
pronounced gradient from northwest to southeast across the
outflow/front, and support decreasing organization as clusters reach
the Lake MI vicinity. Scattered damaging winds should be the
predominant hazard.

A broad low-level jet will nocturnally strengthen from the southern
High Plains to the Lower MO Valley. Regenerative storm development
is expected in the IA vicinity along the trailing front as it
becomes quasi-stationary and orients west/east. With ample buoyancy
lingering, modest organization into small-scale bows is possible on
Saturday night, yielding another round of damaging wind potential.

...Central/southern High Plains...
A cold front pushing south on D1 should become quasi-stationary over
the southern High Plains in the TX Panhandle tomorrow. Isolated
storms are possible near the boundary with a threat for sporadic
microbursts amid hot temperatures south of the front. Farther north
along the Front Range, a post-frontal upslope flow regime will favor regenerative supercell development commencing by late afternoon.
With modestly enhanced mid-level westerlies atop the weak low-level
easterlies, strong deep-layer shear and adequate buoyancy will favor
a risk of large to significant severe hail centered on
east-central/southeast CO. A low-amplitude shortwave impulse
ejecting towards the southern Rockies should foster thunderstorms
persisting well into Saturday night. While buoyancy will nocturnally
weaken, isolated severe hail/wind may occur from eastern CO into
western KS.

..Grams.. 08/08/2025

$$

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ACUS02 KWNS 090558
SWODY2
SPC AC 090556

Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1256 AM CDT Sat Aug 09 2025

Valid 101200Z - 111200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM EASTERN
COLORADA ACROSS KANSAS AND INTO PARTS OF MISSOURI...

...SUMMARY...
Isolated severe thunderstorms are possible from parts of eastern
Colorado across southern Kansas and into northern Missouri. Hail may
occur over western areas, with locally strong gusts over eastern
areas.

...Synopsis and Discussion...
On Sunday, a relatively weak and broad upper trough will exist
across the central and northern Plains, with modest southwest flow
aloft averaging 20-35 kt extending from CO/KS into the upper Great
Lakes. While winds aloft will not be particularly strong, 500 mb
temperatures to -10 C will extend as far south as northern NM and
OK.

At the surface, high pressure will exist over much of the
Intermountain West and into the central Plains. A boundary will
stretch roughly from the TX Panhandle into northern MO/IL, with
eastern parts of the boundary associated with early day storm
outflow.

Two primary areas of isolated severe potential will exist. One will
be from northern MO into eastern KS, south of the composite front
and where daytime heating and 70s F dewpoints will lead to over 3000
J/kg MUCAPE, with lightly veering winds with height. The result will
be evolving/propagating areas of storms with locally strong wind
gusts during late afternoon and into the evening as southerly winds
increase at 850 mb.

The other area will be along the Front Range during the late
afternoon, and extending east/southeast near the boundary into
southern KS. Here, easterly surface winds in the post-frontal regime
over CA and cool temperatures aloft combined with 30 kt midlevel southwesterlies may favor initial cells with hail. With time,
activity should aggregate outflows with sporadic severe gusts
possibly into KS or parts of the OK/TX Panhandles.

..Jewell.. 08/09/2025

$$

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ACUS02 KWNS 091659
SWODY2
SPC AC 091658

Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1158 AM CDT Sat Aug 09 2025

Valid 101200Z - 111200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS SUNDAY THROUGH
SUNDAY NIGHT ACROSS PARTS OF THE SOUTHERN ROCKIES AND CENTRAL GREAT
PLAINS INTO LOWER MISSOURI VALLEY...

...SUMMARY...
Isolated to widely scattered strong thunderstorms may impact a
corridor from the southern Rockies into the lower Missouri Valley
Sunday through Sunday night, accompanied by a risk for potentially
damaging wind gusts and some hail.

...Discussion...
Models indicate that mid/upper ridging will remain generally
prominent across the subtropical through mid-latitudes of the
western Atlantic through eastern Pacific. Between a pair of
relative centers of higher heights, offshore of the Atlantic and
Pacific coasts, a notable mid-level low, initially centered near the
central Canadian/U.S. border vicinity, is forecast to transition to
an open wave and accelerate across northwestern Ontario through
northern Quebec Sunday through Sunday night. This is likely to be
trailed by a short wave trough digging east southeast of the
Canadian Rockies, through the Canadian Prairies.

South of the international border, weak cyclonic flow is forecast to
linger between the ridging, across the Rockies through Great Plains
and upper Mississippi Valley into upper Great Lakes region. One
embedded short wave perturbation may gradually turn east of the
Colorado Rockies through central Great Plains, perhaps preceded by
one or two convectively generated or augmented perturbations across
parts of the lower Missouri Valley toward Upper Midwest/Great Lakes
vicinity.

Near/beneath the southern periphery of this regime, it appears that
the remnants of an initially broad plume of warm, elevated
mixed-layer air advecting to the east of the Rockies will continue
to become suppressed south/southwestward across the lower Missouri
Valley and south central Great Plains. However, associated
relatively dry lower/mid-tropospheric profiles with at least
modestly steep lapse rates may still contribute to sizable CAPE, and
an environment potentially conducive to downbursts and substantive
surface cold pools in convective development. This should be
maximized where seasonably high boundary-layer moisture content
persists, in the wake of a stalled to slowly southward advancing
convectively reinforced cold front across the central Great Plains,
and either side of it across the lower Missouri Valley.

...Southern Rockies into lower Missouri Valley...
Sub-synoptic developments still characterized by relatively low
predictability, including potential convective evolution today into
early Sunday, may considerably influence the convective potential
for Sunday through Sunday night. The potentially focusing surface
front and associated corridor of destabilization may be most
impacted, with the environment otherwise likely to be rather
marginal for organized severe thunderstorm development, in the
presence of modest forcing for ascent and weak deep-layer mean
flow/shear. But, the evolution of one or two thunderstorm clusters
with potential to produce swaths of strong to severe gusts does not
appear out of the question, particularly to the lee of the Front
Range/Sangre de Cristo Mountains into the central Great Plains late
Sunday into Sunday night, aided by the most notable short wave
impulse and, perhaps, a nocturnally strengthening southerly
low-level jet.

..Kerr.. 08/09/2025

$$

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ACUS02 KWNS 091724
SWODY2
SPC AC 091722

Day 2 Convective Outlook CORR 1
NWS Storm Prediction Center Norman OK
1222 PM CDT Sat Aug 09 2025

Valid 101200Z - 111200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS SUNDAY THROUGH
SUNDAY NIGHT ACROSS PARTS OF THE SOUTHERN ROCKIES AND CENTRAL GREAT
PLAINS INTO LOWER MISSOURI VALLEY...

CORRECTED TORNADO PROBABILITY GRAPHIC

...SUMMARY...
Isolated to widely scattered strong thunderstorms may impact a
corridor from the southern Rockies into the lower Missouri Valley
Sunday through Sunday night, accompanied by a risk for potentially
damaging wind gusts and some hail.

...Discussion...
Models indicate that mid/upper ridging will remain generally
prominent across the subtropical through mid-latitudes of the
western Atlantic through eastern Pacific. Between a pair of
relative centers of higher heights, offshore of the Atlantic and
Pacific coasts, a notable mid-level low, initially centered near the
central Canadian/U.S. border vicinity, is forecast to transition to
an open wave and accelerate across northwestern Ontario through
northern Quebec Sunday through Sunday night. This is likely to be
trailed by a short wave trough digging east southeast of the
Canadian Rockies, through the Canadian Prairies.

South of the international border, weak cyclonic flow is forecast to
linger between the ridging, across the Rockies through Great Plains
and upper Mississippi Valley into upper Great Lakes region. One
embedded short wave perturbation may gradually turn east of the
Colorado Rockies through central Great Plains, perhaps preceded by
one or two convectively generated or augmented perturbations across
parts of the lower Missouri Valley toward Upper Midwest/Great Lakes
vicinity.

Near/beneath the southern periphery of this regime, it appears that
the remnants of an initially broad plume of warm, elevated
mixed-layer air advecting to the east of the Rockies will continue
to become suppressed south/southwestward across the lower Missouri
Valley and south central Great Plains. However, associated
relatively dry lower/mid-tropospheric profiles with at least
modestly steep lapse rates may still contribute to sizable CAPE, and
an environment potentially conducive to downbursts and substantive
surface cold pools in convective development. This should be
maximized where seasonably high boundary-layer moisture content
persists, in the wake of a stalled to slowly southward advancing
convectively reinforced cold front across the central Great Plains,
and either side of it across the lower Missouri Valley.

...Southern Rockies into lower Missouri Valley...
Sub-synoptic developments still characterized by relatively low
predictability, including potential convective evolution today into
early Sunday, may considerably influence the convective potential
for Sunday through Sunday night. The potentially focusing surface
front and associated corridor of destabilization may be most
impacted, with the environment otherwise likely to be rather
marginal for organized severe thunderstorm development, in the
presence of modest forcing for ascent and weak deep-layer mean
flow/shear. But, the evolution of one or two thunderstorm clusters
with potential to produce swaths of strong to severe gusts does not
appear out of the question, particularly to the lee of the Front
Range/Sangre de Cristo Mountains into the central Great Plains late
Sunday into Sunday night, aided by the most notable short wave
impulse and, perhaps, a nocturnally strengthening southerly
low-level jet.

..Kerr.. 08/09/2025

$$

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ACUS02 KWNS 100555
SWODY2
SPC AC 100554

Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1254 AM CDT Sun Aug 10 2025

Valid 111200Z - 121200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS CENTERED OVER
THE TEXAS PANHANDLE AND SOUTH PLAINS...

...SUMMARY...
A few marginally severe storms will be possible Monday from late
afternoon through the evening, centered over the southern Texas
Panhandle and South Plains. Scattered notable storms may also occur
over parts of North Dakota into northern Minnesota.

...Southern High Plains to the Lower MO Valley...
Relatively cool midlevel temperatures will remain over the Plains,
with 20-25 kt midlevel westerlies. At the surface, a moist axis will
extend roughly from the eastern TX Panhandle into MO, with northeast
surface winds from KS into northwest TX early.

As heating occurs, low-level winds should veer to east/southeast,
with around 2000 J/kg MUCAPE developing by peak heating. Storms are
likely to develop from northeast NM into TX as the air mass will be
uncapped. Directional wind change with height will support a few
longer-lived cells producing hail. A few aggregate clusters may also
produce locally severe gusts through early evening.

...ND into northern MN...
A speed max will dive southeastward out of SK and MT, with midlevel
vorticity maximum spread across ND and northwest MN late in the day.
This will occur at a time of peak heating near a surface trough
which will be draped NE to SW across the area. Given the focus for
ascent and uncapped air mass, scattered storms will develop beneath
the cool temperatures aloft. Despite limited moisture, a few cells
may produce primarily small hail and locally strong gusts.

..Jewell.. 08/10/2025

$$

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ACUS02 KWNS 101720
SWODY2
SPC AC 101718

Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1218 PM CDT Sun Aug 10 2025

Valid 111200Z - 121200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS LATE MONDAY
AFTERNOON AND EVENING ACROSS PARTS OF EASTERN NORTH
DAKOTA...NORTHWESTERN MINNESOTA...EAST CENTRAL NEW MEXICO AND
NORTHWESTERN TEXAS...

...SUMMARY...
Strong thunderstorms accompanied by at least some risk for severe
wind and hail may impact parts of eastern New Mexico into the Texas
South Plains, as well as parts of eastern North Dakota into
northwestern Minnesota, late Monday afternoon and evening.

...Discussion...
While the westerlies generally remain confined to the higher
latitudes, one significant embedded short wave trough is forecast to
continue digging southeast of the Canadian Prairies through the
international border vicinity, to the west of the Great Lakes,
during this period. It appears that this will be accompanied by one
initial surge of cooler/drier boundary layer air across much of the
Dakotas and portions of the Upper Midwest/adjacent Great Lakes
region by late Monday night.

Otherwise, weak mid-level troughing likely will linger across much
of the remainder of the interior U.S., to the east of the Rockies,
between large-scale mean ridging centered offshore of both the
Pacific and Atlantic coasts. An associated weak surface frontal
zone, still reinforced by convective outflow in some locations, is
likely to linger across the Great Lakes through lower Missouri
Valley and Texas South Plains into early Monday, before generally
continuing to weaken through the period.

Seasonably high boundary-layer moisture content probably will be
maintained ahead of the stalled/slow moving remnant front, across
much of the Southwest, as well as in a corridor along and to the
north it. Some of this moisture across the lower/middle Missouri
Valley may begin to advect northward ahead of the lead reinforcing
cool intrusion late Monday into Monday night.

...Southern Great Plains into Great Lakes...
The seasonably high boundary-layer moisture content, along/just
north of the weakening front, may provide support for the
development of moderate to locally higher CAPE with insolation
Monday. As this occurs, it appears that a number of convectively
generated or augmented perturbations within the generally weak
southwesterly deep-layer mean flow could contribute to scattered
thunderstorm development during and after peak heating. Some of this
could pose a risk for localized potentially damaging wind gusts, but
the coverage of any such activity still seems likely to remain
rather sparse in nature.

One possible exception may develop along a modifying segment of the
boundary across parts of east central New Mexico into the Texas
South Plains by late Monday afternoon or evening, beneath steeper
mid-level lapse rates associated with the remnants of a plume of
warm elevated mixed-layer air. There appears a general consensus
within the various model output that a digging short wave impulse,
within a weak northwesterly mid-level regime, may provide support
for a relatively notable upscale growing/southeastward propagating
thunderstorm cluster.

Farther northeast, the NAM, perhaps more so than other model output,
suggests that a notable MCV may emerge from Sunday night convection
over the central Great Plains, before slowly migrating across the
lower Missouri Valley toward the Great Lakes Monday through Monday
night. It is possible that a perturbation of the strength suggested
by the NAM could, at some point, support another notable evolving
cluster with potential to produce strong wind gusts. At this point,
however, the potential for this still seems low, with too much
uncertainty to introduce 5 percent probabilities without unduly
large false alarm area.

...Northern Great Plains...
A moistening boundary-layer, aided by evapotranspiration and perhaps
the onset of better low-level moisture return on strengthening
southerly low-level flow, may contribute to moderate CAPE within a
corridor of stronger pre-frontal surface heating by late afternoon.
Coupled with strengthening deep-layer mean wind fields and shear,
downstream of a digging 50+ kt 500 mb jet, it appears that the
environment may become conducive to vigorous convective development
capable of producing small to marginally severe hail and strong
surface gusts. Potential for gusts approaching or exceeding severe
limits appears highest during the late afternoon and early evening
across parts of eastern North Dakota into northwestern Minnesota,
where warm, unsaturated low-level thermodynamic profiles with steep
lapse rates will aid downward momentum transfer via enhanced melting
and evaporative cooling in downdrafts.

..Kerr.. 08/10/2025

$$

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ACUS02 KWNS 110532
SWODY2
SPC AC 110531

Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1231 AM CDT Mon Aug 11 2025

Valid 121200Z - 131200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER FAR EASTERN
WISCONSIN AND UPPER MICHIGAN...

...SUMMARY...
Scattered strong thunderstorms may impact parts of the upper Great
Lakes region Tuesday.

...Synopsis and Discussion...
The main feature of interest will be a shortwave trough moving
across the upper MS Valley and across the Great Lakes, with
attendant cold front pushing east across Upper MI and WI through
00Z. Modest instability and lift along the front will likely result
in scattered afternoon thunderstorms over these areas.

While lapse rates will remain poor aloft, the combination of
strengthening deep-layer shear and frontal passage near peak heating
may yield a few stronger storms within an expected line across
eastern WI. Mean wind speeds in the lowest 3km will not be very
strong, nor will the mixed boundary layer be particularly deep.
However, isolated damaging gusts or marginal hail may occur as
cooling aloft overspreads the warmed air mass late.

Elsewhere, scattered storms will occur over the Southern Plains
beneath a weak midlevel disturbance, and over parts of the Midwest
and Southeast where low-level moisture will favor sporadic afternoon development.

..Jewell.. 08/11/2025

$$

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ACUS02 KWNS 111710
SWODY2
SPC AC 111709

Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1209 PM CDT Mon Aug 11 2025

Valid 121200Z - 131200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS TUESDAY INTO
TUESDAY NIGHT ACROSS PARTS OF EASTERN WISCONSIN...UPPER AND LOWER MICHIGAN...AND PARTS OF NORTHEASTERN ILLINOIS...NORTHERN
INDIANA...NORTHWESTERN OHIO...

...SUMMARY...
Strong thunderstorms may impact parts of the upper Great Lakes
region Tuesday into Tuesday evening, accompanied by at least some
risk for severe wind and hail.

...Discussion...
The westerlies will remain confined to the northern mid-latitudes,
but models suggest that flow near/north of the Canadian/U.S. border
will trend a bit more zonal, as an initially prominent mid-level
high centered offshore of the Pacific Northwest continues to become
suppressed west-southwestward across the northeastern Pacific.
Within this regime, models continue to indicate the consolidation of
several short wave perturbations into larger-scale mid-level
troughing across Ontario into Quebec by late Tuesday night,
accompanied by significant surface cyclogenesis across far northern
Ontario into the southern Hudson/James Bay vicinity.

In lower levels, a modest initial intrusion of cooler/drier air may
overspread much of the Dakotas and portions of the Upper Midwest and
adjacent Great Lakes region by 12Z Tuesday, before slowly advancing east-southeastward across the upper Great Lakes and eventually being
overtaken by a more substantive cool intrusion later Tuesday through
Tuesday night. Complicating matters with respect to
destabilization, guidance continues to indicate that the lead front
will be preceded by a stalled lingering remnant frontal zone, which
may still be reinforced by convective precipitation/outflow across
parts of southern Lower Michigan and northern Illinois, into the
lower Missouri Valley and the southern Great Plains, at the outset
of the period.

...Upper Great Lakes...
Short wave developments within the evolving pattern remain unclear
due to spread within the various model output, but guidance
continues to indicate that one notable short wave impulse will
continue digging across parts of the Upper Midwest and adjacent
Great Lakes region during the day Tuesday, before pivoting across
and east-northeast of Lake Huron/Georgian Bay. It appears that this
may be preceded by one or two convectively generated perturbations
which will become increasing sheared while merging into the
southwesterly cyclonic mid-level regime overspreading the Great
Lakes vicinity.

As this occurs, various model output (notably including calibrated
thunderstorm probability guidance from the High Resolution Ensemble
system) suggests that destabilization and forcing for ascent will
become supportive of a couple of corridors of increasing
thunderstorm development by late Tuesday afternoon. These generally
coincide with the stalled remnant frontal zone across parts of
southeastern Lower Michigan into northeastern Illinois and the
initial cold front advancing across Upper Michigan/eastern
Wisconsin.

Along the southern boundary, which may strengthen some with
differential surface heating, mid-level thermodynamic profiles may
be relatively warm with weak lapse rates. However, it still appears
that seasonably high boundary-layer moisture content, coupled with
daytime heating, will contribute to sizable CAPE. Coinciding with a
belt of strengthening southwesterly lower/mid-level flow (including
30-40 kt in the 700-500 mb layer), the environment may become
conducive to organized convection, including evolving supercell
structures and upscale growing clusters with potential to produce
strong to severe wind gusts by late Tuesday afternoon into evening.

Across Upper Michigan into eastern Wisconsin, pre-frontal
destabilization remains more unclear due to the possible influence
of convective cloud cover and/or outflow. But, with breaks in cloud
cover allowing for a narrow corridor of heating, cooling aloft and strengthening shear along the frontal zone might contribute to an
environment conducive to strong thunderstorm development with
potential to produce marginally severe hail and localized strong
surface gusts late Tuesday afternoon.

...Southwest...
Forecast deep-layer mean wind fields are generally light, but
include a west-northwesterly upslope component to the low-level flow
beneath north-northeasterly mid-level flow. This may aid
propagation of convection off the higher terrain of southwestern New
Mexico and southeastern Arizona, into lower elevations with a warm
and deeply mixed boundary layer characterized by modest potential
instability by late Tuesday afternoon. As this occurs, a few strong
to severe downbursts and gusts along strengthening outflows appears
possible.

..Kerr.. 08/11/2025

$$

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ACUS02 KWNS 120529
SWODY2
SPC AC 120528

Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1228 AM CDT Tue Aug 12 2025

Valid 131200Z - 141200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS CENTERED OVER
SOUTH DAKOTA...

...SUMMARY...
The evolution of an organized cluster of thunderstorms accompanied
by strong to severe wind gusts appears possible across parts of
central through eastern South Dakota by Wednesday evening.

...Discussion...
As a low-amplitude shortwave trough progresses over the northern
Rockies, a surface low will develop into southern SK, with a
secondary low into western SD late in the day. Southerly low-level
winds will develop over the Plains, with increasing 850 mb winds of
40-50 kt overnight from NE into SD.

Initially, the air mass will be relatively dry. However, a plume of
60s F dewpoints will materialize across the mid MO Valley, with
strong heating over the High Plains a near the surface trough.

Storms may develop near 00Z over parts of SD near the Black Hills
and near the surface low/lapse rate plume, with an initial hail
risk. With time, storms should produce strong outflow, with a few
severe gusts possible. Due to limited moisture, capping will become
a mitigating factor after 00Z, and may preclude a more robust MCS.
As such, a Marginal Risk remains valid for primarily isolated severe
activity withing the broader zone of convection.

..Jewell.. 08/12/2025

$$

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ACUS02 KWNS 121733
SWODY2
SPC AC 121732

Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1232 PM CDT Tue Aug 12 2025

Valid 131200Z - 141200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS
SOUTH-CENTRAL SOUTH DAKOTA AND FAR NORTH-CENTRAL NEBRASKA...

...SUMMARY...
The evolution of an organized cluster of thunderstorms accompanied
by strong to severe wind gusts appears possible across parts of
central through eastern South Dakota and far north-central Nebraska
by Wednesday evening.

...Synopsis...
Upper ridging will remain anchored over the Southwest/Four Corners,
with subtropical ridging staying over FL as well. A pair of
low-amplitude shortwave troughs will progress through the westerly
flow north of this ridging. The easternmost wave will likely move
through the Lower OH and TN Valleys while the westernmost wave
progresses along the MT/WY border and through SD. This western wave
is forecast to interact with an unstable airmass to support strong
to severe thunderstorms from eastern WY into the Dakota and NE.
Additional thunderstorms are expected across much of the eastern
CONUS. Storms over the Northeast will be fostered by glancing ascent
attendant to a shortwave trough moving through Quebec while the
previously mentioned shortwave trough moving the TN Valley will
promote development from KY/TN into northern AL/MS. Weak shear
should limit storm organization and strength throughout the eastern
CONUS.

...Eastern WY into the Dakotas and NE...
Elevated showers and thunderstorms will likely be ongoing across western/central SD Wednesday morning. These storms are generally
expected to be subsevere but will likely persist while gradually
shifting eastward throughout the morning into the afternoon. The
evolution of these storms, and their associated outflow and cloud
cover, introduces some uncertainty into the forecast, particularly
across southeast SD and northeast NE where there is at least a low
probability for reintensification of storms within this cluster. At
this time, given potential capping and varied model solutions
confidence is low in the reintensification scenario.

A more probable severe potential will result from the thunderstorm
development that initiates farther west across the Black Hills.
Here, increased forcing for ascent attendant to the approaching
shortwave trough amid a warm, deeply mixed, and unstable airmass
will support convective initiation late Wednesday afternoon. These
initially high-based storms will pose a risk for damaging gusts and
isolated hail. Moisture and buoyancy will increase with eastern
extent, which will combine with moderate vertical shear to support a
corridor of higher severe-wind probability across south-central SD
and north-central NE during the late evening. Thereafter, increasing
convective inhibition should result in gradually diminishing storm
intensity. Additionally, elevated thunderstorms with some hail risk
may develop ahead of the convective line across eastern SD during
the late evening and overnight. Here, a strengthening low-level jet
and associated warm-air advection amid steep mid-level lapse rates
and moderate deep-layer shear could support a few storms capable of
large hail.

..Mosier.. 08/12/2025

$$

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ACUS02 KWNS 130552
SWODY2
SPC AC 130550

Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1250 AM CDT Wed Aug 13 2025

Valid 141200Z - 151200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM EASTERN NORTH
DAKOTA AND FAR NORTHEAST SOUTH DAKOTA INTO NORTHWEST MINNESOTA...

...SUMMARY...
Severe storms producing hail and wind are possible mainly from
eastern North Dakota into northwest Minnesota Thursday afternoon and
evening. Isolated severe storms may occur across parts of South
Dakota into western Nebraska.

...Synopsis...
A shortwave trough will move eastward across the northern Plains on
Thursday, with the primary upper low well north into Canada. The
southern periphery of this wave will move across ND and northern MN
late day and overnight, with minimal cooling aloft and increasing
mid to upper level winds of 40-50 kt.

At the surface, a trough will extend from central ND into western SD
during the afternoon, where a surface low will exist within the warm
plume. Southeast winds will bring moisture northward ahead of the
front, with moderate instability forecast. Effective shear of 40-50
kt will develop late as the upper wave approaches and low-level jet
increases to 30-40 kt.

Storms are likely to form near 00Z along the cold front over
central/eastern ND and extending into northern SD, and progress
across northwest MN during the evening. Large hail appears likely as
storm mode should be cellular, but areas of severe gusts may occur.
Steep lapse rates aloft and strong instability may also yield hail
over 2.00" diameter. Strong heating into central SD and western NE
will likely yield isolated strong to severe storms as well with
brief hail and locally strong gusts.

..Jewell.. 08/13/2025

$$

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ACUS02 KWNS 131718
SWODY2
SPC AC 131718

Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1218 PM CDT Wed Aug 13 2025

Valid 141200Z - 151200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR EASTERN NORTH DAKOTA...NORTHWEST MINNESOTA...AND FAR NORTHEAST SOUTH DAKOTA...

...SUMMARY...
Severe storms producing hail and wind are possible mainly from
eastern North Dakota into northwest Minnesota Thursday afternoon and
evening. Isolated severe storms may occur across parts of South
Dakota into western Nebraska.

...Synopsis...
A mid-level shortwave trough and ongoing convection should be
located somewhere near eastern South Dakota Thursday morning and
weaken as it moves toward Lake Superior by 12Z Friday. Stronger
mid-level flow along the northern periphery of a broad ridge
centered over the Plains will shift east across the Canadian
Prairies and northern Plains during the day on Thursday. A lee
cyclone will be present across Saskatchewan/Manitoba at the
beginning of the period and move east through the day. A surface
trough/dryline will extend south from this surface low into the northern/central Plains. A cold front will strengthen through the
period and eventually shift south across eastern Montana/North
Dakota.

...Northern Plains...
Thunderstorms associated with a passing mid-level shortwave trough
will likely be across eastern South Dakota at the start of the
period and advance east through the day. In the wake of this wave,
subsidence should suppress convection for most of the day. By
evening, strong heating should result in an uncapped environment
amid strong instability. Upper forcing appears quite nebulous amid
neutral to slightly rising heights. Therefore, storm coverage
remains questionable. The best chance for scattered storm coverage
will be across northeast North Dakota and far northwest Minnesota
where scattered supercells capable of large hail (some very large)
and severe wind gusts are expected. Farther south, storm coverage is
less likely. However, given the strong heating along the
dryline/surface trough, at least isolated storm development should
occur and the environment would support severe storms.

...Central South Dakota into northwest Nebraska...
Strong heating and very strong instability is expected to develop
along the trough from central South Dakota into northwest Nebraska.
Weak forcing should result in isolated storm coverage along this
boundary during the late afternoon/evening. Shear will not be as
strong this far south, but high-based storms may still be capable of
isolated large hail and severe wind gusts.

..Bentley.. 08/13/2025





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ACUS02 KWNS 140541
SWODY2
SPC AC 140539

Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1239 AM CDT Thu Aug 14 2025

Valid 151200Z - 161200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER PARTS OF
THE NORTHERN PLAINS AND UPPER MISSISSIPPI VALLEY...

...SUMMARY...
At least isolated severe storms may occur over parts of the northern
Plains and Upper Mississippi Valley on Friday.

...Synopsis......
An upper low will move from Manitoba toward Hudson Bay on Friday,
with minor height rises over the northern Plains as the upper trough
departs to north. An upper high will build over central Plains to
lower MO Valley, while weak troughiness persists over the Great
Basin.

At the surface, a cold front from northern MN toward the ND/SD
border will bring drying, but will stall late in the day. A large
area of instability will develop over much of SD, MN, WI, IA and NE
as dewpoints increase, and easterly surface winds will bring
moisture westward across SD and into southeast MT and northeast WY.

...Eastern SD into MN and western WI...
Storms are expected to form relatively early in the day in a warm
advection regime with southwest 850 mb winds of 30-40 kt. This
regime may favor clusters of storms with localized severe gust
potential. Modest shear could favor a few longer-lived storm cores
producing hail as well. Overall predictability is low given the
initiation regime and possibility of early day storms in the area.

...Black Hills and Vicinity...
Substantial easterly low-level flow will develop during the day as
winds back from northeast to east/southeast. This will push 60s
dewpoints as far west as southeast MT/northeast WY, beneath 30+ kt
midlevel westerly winds. This will result in elongated, straight
hodographs favorable for cellular storms producing large hail. While
storms may be quite isolated, hail could be damaging.

..Jewell.. 08/14/2025

$$

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ACUS02 KWNS 141733
SWODY2
SPC AC 141731

Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1231 PM CDT Thu Aug 14 2025

Valid 151200Z - 161200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS CENTRAL
WISCONSIN AND FAR EASTERN MINNESOTA...

...SUMMARY...
Scattered severe storms are likely over parts of the northern Plains
and Upper Mississippi Valley on Friday.

...Synopsis...
A belt of stronger mid-level flow will be present across the
northern Plains on Friday along the northern periphery of a broad
mid-level ridge. Within this flow, a weak mid-level shortwave trough
(perhaps amplified by Day1/Thursday convection across the central
Rockies) will move across the northern Plains and into the Upper
Midwest. This feature may be a focus for severe storms on Friday afternoon/evening. Another weak mid-level shortwave trough is
forecast to traverse the central Rockies with associated ascent
overspreading the central/northern High Plains. At the surface, weak
lee troughing will be present across the central/northern High
Plains with a front extending northeast across the northern Plains
and into the Upper Midwest.

...Upper Midwest...
Moderate to strong instability is forecast to develop south of a
stationary front across the Upper Midwest Friday afternoon. The
combination of ascent associated with a passing weak mid-level
shortwave trough and strengthening isentropic ascent as the
low-level jet strengthens, may provide ample lift for scattered
thunderstorms Friday afternoon/evening. Several CAMS are in
relatively good agreement for convective initiation across eastern
Minnesota with the potential for upscale growth into a MCS across
Wisconsin late Friday evening. Have introduced a Slight Risk across
this region for an initial large hail threat, followed by an
increasing severe wind threat if storms grow upscale. However, this
area may need to be moved or enlarged in later outlooks due to the
inherent lack of predictability within a low-amplitude pattern. Some
of this unpredictability can be seen by relative outliers (HRRR and
MPAS) which seems to stem from difference in convective evolution on
Day 1/Thursday across the central Rockies and adjacent Plains
tonight.

...Central/Northern High Plains into the northern Plains...
Another weak mid-level shortwave trough is expected to traverse the
Rockies on Friday and eventually overspread the northern Plains by
Friday evening. Moderate to strong instability and moderate shear
along the southern periphery of the stronger mid-level westerlies
may result severe storms. Large hail would be possible in the
initial, cellular stages (isolated severe wind across the NE
Panhandle where a hot/well-mixed environment will be present),
before an increasing severe wind threat may develop by later in the
evening across South Dakota. If this MCS can maintain itself far
enough east during the evening, the strengthening low-level jet
across central and eastern South Dakota could maintain this MCS with
some isolated severe wind threat into the early morning hours on
Saturday across eastern South Dakota and perhaps far western
Minnesota and northwest Iowa.

..Bentley.. 08/14/2025

$$

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ACUS02 KWNS 150558
SWODY2
SPC AC 150556

Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1256 AM CDT Fri Aug 15 2025

Valid 161200Z - 171200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM PARTS OF
THE NORTHERN HIGH PLAINS EASTWARD TO THE GREAT LAKES...

...SUMMARY...
Thunderstorms with a potential for isolated severe gusts and hail
will be possible on Saturday from parts of the central and northern
Plains eastward to the Great Lakes.

...Central and Northern Plains...
At mid-levels, a ridge will move across the northern Plains on
Saturday, as southwesterly flow remains from the northern Rockies
into the northern High Plains. At the surface, an upslope flow
regime will remain in place from the Dakotas into eastern Montana.
A surface trough will deepen during the day over the northern High
Plains. Although large-scale ascent will remain weak across the
region, isolated thunderstorms may develop in the afternoon near the
surface trough. Additional isolated storms could develop near and to
the north of a front located across northern Nebraska. To the north
of the front, a moist and unstable airmass is forecast. Moderate
instability will be in place over much of this airmass by afternoon.
Although deep-layer shear will remain near or below 35 knots over
most of this airmass, low to mid-level lapse rates will be steep.
This could be enough for isolated severe gusts and hail with any
cell that can develop and persist in the late afternoon and early
evening.

...Upper Mississippi Valley/Great Lakes...
West-northwesterly mid-level flow will remain in place on Saturday
from the upper Mississippi Valley into the Great Lakes, as a
mid-level ridge moves across the northern Plains. At the surface, a
front is forecast to remain in place from far northern Iowa into
southern Wisconsin. From near the boundary southward, surface
dewpoints are forecast to be in the lower to mid 70s F. This will
contribute to a strongly unstable airmass by afternoon. Although
large-scale ascent will remain weak across the region, isolated
thunderstorms may develop along pre-existing boundaries or along
zones of maximized low-level convergence. NAM forecast soundings
near and to the north of the front across the upper Mississippi
Valley have 0-6 km shear in the 30 to 40 knot range, with 700-500 mb
lapse rates of 7 to 7.5 C/km. This could be enough for isolated
rotating storms with potential for hail and severe wind gusts. A
potential for severe gusts could extend eastward into parts of the
Great Lakes where moderate instability is forecast, but deep-layer
shear will be more modest.

..Broyles.. 08/15/2025

$$

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ACUS02 KWNS 151736
SWODY2
SPC AC 151735

Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1235 PM CDT Fri Aug 15 2025

Valid 161200Z - 171200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR MUCH OF SOUTH
DAKOTA...

...SUMMARY...
Scattered severe thunderstorms are possible Saturday over South
Dakota primarily during the late afternoon through the late evening
period. Large hail and severe gusts appear to be the primary
hazards with the stronger storms.

...Northern Great Plains...
A mid-level ridge centered over the lower MS Valley/Mid South will
feature a weak disturbance moving from the WY/CO vicinity into the
Dakotas Saturday night. A residual composite front will remain
draped east-west from the Upper Midwest into western SD, where it
will intersect a lee trough from the central High Plains
north-northwestward into eastern MT. Although large-scale ascent
will remain fairly weak across the region, isolated thunderstorms
will likely develop in the vicinity of the lee trough and Black
Hills by the late afternoon as convective inhibition erodes. To the
north of the front, a moist and unstable airmass featuring a
moderate to very unstable boundary layer will develop by mid-late
afternoon. Model guidance shows a gradual increase in storm
coverage during the early evening over western/central SD. Ample
directional shear will support effective shear magnitudes 30-40 kt
and storm organization with the stronger storms. Large hail and
severe gusts appear to be the primary threats.

...Midwest...
A linear cluster of thunderstorms is expected to be ongoing Saturday
morning across parts of the Upper MS Valley/western Great Lakes.
Model guidance differs on the evolution of this potentia
shower/thunderstorm activity, but west-northwesterly mid-level flow
poleward of a mid-level anticyclone centered over the lower MS
Valley, will potentially favor some continuation of storms
downstream across the southwestern Great Lakes. Models continue to
show a moist/unstable airmass across southern portions of the Great
Lakes. Although large-scale ascent will remain weak across the
region, regenerative storm development on remnant outflow may yield
a subsequent evolution of a storm cluster but uncertainty remains
high. Isolated damaging gusts/hail are the main threats with these
storms.

..Smith.. 08/15/2025

$$

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ACUS02 KWNS 160546
SWODY2
SPC AC 160545

Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1245 AM CDT Sat Aug 16 2025

Valid 171200Z - 181200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM PARTS OF
THE NORTHERN PLAINS EAST-SOUTHEASTWARD INTO THE SOUTHERN GREAT LAKES
AND OHIO VALLEY...

...SUMMARY...
Thunderstorms with potential for isolated severe wind gusts and hail
will be possible on Sunday across parts of the northern Plains east-southeastward into the Upper Midwest, southern Great Lakes and
Ohio Valley.

...Northern Plains/Mid Missouri Valley...
At mid-levels, west-southwesterly flow will remain over the northern
Plains on Sunday. At the surface, upslope flow will gradually become established over much of the western and central Dakotas, as a low
deepens over eastern Montana. An axis of moderate instability is
forecast to develop by afternoon from southern South Dakota
northwestward into eastern Montana. Large-scale ascent will be weak
along this corridor keeping convective coverage isolated. Mid-level
lapse rates are forecast to be steep and 0-6 km shear is forecast to
be mostly in the 25 to 35 knot range. This may be enough for an
isolated threat for hail and severe wind gusts in the late afternoon
and early evening.

...Upper Mississippi Valley/Southern Great Lakes/Ohio Valley.
A mid-level ridge will remain in place across the upper Mississippi
Valley on Sunday. From near the ridge axis and to the east, strong
instability is forecast to develop by afternoon from northeast Iowa
into northern Illinois and northern Indiana. Large-scale ascent will
remain limited, which will keep convective coverage isolated. If a
cell or two can initiate and persist, the strong instability could
be enough for a few marginally severe gusts.

To the west of the mid-level ridge axis across Minnesota, isolated
to scattered thunderstorms may develop during the afternoon due to a
subtle shortwave trough approaching from the southwest. While
moderate deep-layer shear is forecast across much of Minnesota, this
convection will likely remain well to the north of the axis of
instability. For this reason, any threat for severe wind gusts and
hail should be marginal.

..Broyles.. 08/16/2025

$$

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ACUS02 KWNS 161728
SWODY2
SPC AC 161727

Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1227 PM CDT Sat Aug 16 2025

Valid 171200Z - 181200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS IN PARTS OF THE
NORTHERN CONUS...

...SUMMARY...
Isolated severe thunderstorms are possible, mainly during the late
afternoon and evening Sunday from the Upper Midwest to the northern
High Plains. Isolated damaging winds are possible on Sunday
afternoon to early evening across the Northeast and New England.

...Upper Midwest...
Decaying convective swaths will likely be ongoing at 12Z Sunday,
centered on the eastern Dakotas to southern MN. The eastern lobe of
this morning activity will aid in strengthening the quasi-stationary
baroclinic zone, as differential boundary-layer heating occurs
across it through the day. Presence of mid to upper ridging
emanating north-northeast from the southern Great Plains anticyclone
will remain a limiting factor to more robust severe potential.
Still, drifting MCVs across the Dakotas in a modest southwesterly
flow regime in conjunction with large buoyancy in the warm-moist
sector should aid in scattered late-afternoon thunderstorm
development. This appears most probable in the eastern SD to
southwest MN vicinity, with isolated coverage trailing into central
NE. A mix of isolated severe hail/wind initially should transition
to mainly sporadic strong to severe gusts through the evening as
slow-moving clusters/MCSs develop. A brief tornado is also possible
with any transient supercell structures near the front.

...Northern High Plains...
Primary severe potential should emanate out of late afternoon
convection initiating off the higher terrain of southern MT and
separately in the Black Hills vicinity. A modest combination of
deep-layer shear and large-scale ascent suggests mainly a strong to
isolated severe threat should be expected as high-based convection
spreads northeast across eastern MT. The presence of weak
surface/low-level should modulate the eastern extent of severe
potential on Sunday evening.

...Northeast/New England...
A shortwave trough will progress across the St. Lawrence Valley
towards the Canadian Maritimes and northern New England through
Sunday afternoon. A cold front will push southeastward through the
day with isolated to widely scattered thunderstorms expected along
it during the afternoon. Buoyancy appears likely to be weak and will
remain a limiting factor to more robust severe potential. More
favorable deep-layer shear will exist in New England where localized
damaging winds and small hail should be favored. Farther southwest,
multicell clustering should be dominant with isolated damaging winds
from sporadic strong gusts.

..Grams.. 08/16/2025

$$

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ACUS02 KWNS 170536
SWODY2
SPC AC 170534

Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1234 AM CDT Sun Aug 17 2025

Valid 181200Z - 191200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM PARTS OF
THE NORTHERN PLAINS EASTWARD TO THE UPPER MISSISSIPPI VALLEY AND
WESTERN GREAT LAKES...

...SUMMARY...
Thunderstorms with potential for isolated severe wind gusts and hail
will be possible on Monday over parts of the central and northern
Plains eastward into the upper Mississippi Valley and western Great
Lakes.

...Central and Northern Plains/Mid Missouri Valley...
At mid-levels, a ridge will build over the northern Plains on
Monday, as flow over much of the north-central U.S. remains from the west-northwest. At the surface, a post-frontal airmass will be in
place over much of the central and eastern Dakotas. Along the
southern and western periphery of this airmass, moderate instability
will likely develop by afternoon from parts of eastern Montana
southeastward into Nebraska. Large-scale ascent will likely remain
limited over much of the region, helping to keep convective
development isolated. Although deep-layer shear should remain below
35 knots in most areas, low to mid-level lapse rates will be steep.
This could be enough for a marginal severe threat, mainly in the
late afternoon and early evening. Severe wind gusts and hail will be
the primary threats.

...Upper Mississippi Valley/Western Great Lakes...
A subtle mid-level shortwave trough is forecast to move eastward
into the upper Mississippi Valley on Monday afternoon. To the east
of the trough, moderate to strong instability is forecast to develop
from central Iowa eastward into northern Illinois. The greatest
convective coverage is expected to develop further to the north
across parts of Wisconsin, where instability will be weaker but
deep-layer shear will be greater. The combination of instability and
deep-layer shear across Wisconsin could be sufficient for a marginal wind-damage threat during the late afternoon and early evening. This
threat, along with a potential for hail could extend southwestward
into central Iowa where strong instability is forecast.

..Broyles.. 08/17/2025

$$

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ACUS02 KWNS 171730
SWODY2
SPC AC 171729

Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1229 PM CDT Sun Aug 17 2025

Valid 181200Z - 191200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS WITHIN THE
CENTRAL/NORTHERN PLAINS AND UPPER MIDWEST...

...SUMMARY...
Strong to severe storms capable of damaging winds are possible in
parts of the Upper Midwest on Monday. Isolated to widely scattered
storms could produce large hail and severe winds in parts of the central/northern Plains.

...Northern/Central Plains...
Isolated to widely scattered storms to develop either along a weak
surface trough, within the terrain in eastern Wyoming/Black Hills,
or a cold front near the Nebraska/South Dakota border. Strong
buoyancy and effective shear of 30-40 kts will allow for the
stronger storms to be organized. Large hail and severe winds would
be the expected hazards. There is some potential for a more
organized cluster of storms to progress eastward. This would most
likely occur near the cold front during late afternoon/evening.
However, a very weak low-level jet and uncertain cold pool
organization keeps confidence too low for any increase in wind
probabilities.

...Upper Midwest...
Showers/thunderstorms are expected to be ongoing Monday morning.
This will have an impact on where the greatest destabilization will
occur during the afternoon. Furthermore, the region will be in the
wake of a departing shortwave trough/MCV with mid-level ascent being
nebulous and uncertain. Current guidance suggests the greatest
potential for afternoon storms will exist in parts of
central/southern Wisconsin into northern Illinois. There, some
surface heating and low-level lift near a weak surface low/triple
point could promote widely scattered to scattered thunderstorms.
While the exact placement of this activity remains uncertain, the
environment would support marginal supercells and multicell clusters
with a primary hazard of damaging winds.

Farther southwest into Iowa, strong buoyancy is expected to develop
south of any outflow from morning activity. MLCAPE around 3000 J/kg
would support a threat for isolated wind damage even with weaker
effective shear than farther north. However, with little in the way
of mid-level ascent and uncertain low-level forcing gives low
confidence in storm coverage.

...Southwest into central Montana...
Though a ridge will be building into the northern Rockies,
sufficient moisture may promote thunderstorm development in the
higher terrain. Flow aloft will be strong enough to support at least
marginally organized storms. However, it is not clear how intense
storms will be given some signal for moisture to mix out during the
afternoon. Strong, gusty outflow winds are possible, but confidence
in severe potential remains low.

..Wendt.. 08/17/2025

$$

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ACUS02 KWNS 180555
SWODY2
SPC AC 180553

Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1253 AM CDT Mon Aug 18 2025

Valid 191200Z - 201200Z

...NO SEVERE THUNDERSTORM AREAS FORECAST...

...SUMMARY...
A severe threat is not expected across the continental U.S. on
Tuesday or Tuesday night.

...DISCUSSION...
A mid-level ridge will build northward across the central Rockies
and northern High Plains on Tuesday, as a subtle shortwave trough
moves through the Great Lakes region. At the surface, a cold front
will advance southward into the Ohio and mid Mississippi Valleys,
extending westward into the southern Plains. As surface temperatures
warm during the day, low-level convergence near the front will be
favorable for isolated to scattered thunderstorm development.
Limited large-scale ascent and weak deep-layer shear will be
unfavorable for severe storms. Further northwest into the
north-central states, moderate instability will be possible by
Tuesday afternoon, mainly in the Dakotas. However, a severe threat
is not expected due to limited large-scale ascent, minimal low-level convergence, and weak deep-layer shear. Elsewhere across the
continental U.S., a severe threat is not expected Tuesday and
Tuesday night.

..Broyles.. 08/18/2025

$$

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ACUS02 KWNS 181730
SWODY2
SPC AC 181728

Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1228 PM CDT Mon Aug 18 2025

Valid 191200Z - 201200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS IN THE SOUTHERN
GREAT PLAINS TO THE MIDWEST...

...SUMMARY...
Localized damaging winds are possible across parts of the Midwest,
Mid-South, and southern Great Plains on Tuesday afternoon to early
evening.

...Midwest to Southern Great Plains...
The upper-level pattern will be characterized by an anticyclone
anchored over the Southwest and a low-amplitude trough/embedded MCVs
from the Great Lakes to the Lower MO Valley. While mid-level winds
will be weak to the southwest of the Great Lakes, low-probability
severe gust/damaging wind potential is evident Tuesday along a
convectively modulated surface front expected to arc from the Lake
Erie vicinity to the Lower OH Valley and trailing into KS/OK. This
should be focused during the afternoon to early evening as scattered
to numerous thunderstorms form along the front, as well as on
pre-existing outflows from early-day convective remnants.

Rather warm boundary-layer temperatures will again support a swath
of large buoyancy, which should have embedded pockets of more muted
MLCAPE where morning convection decays. 12Z HREF and ML guidance
signals are supportive of sporadic strong to severe gusts in wet
microbursts. With weak deep-layer shear, organized clustering
appears unlikely. Thus, isolated damaging winds seem plausible until
convection weakens around sunset.

..Grams.. 08/18/2025

$$

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ACUS02 KWNS 190541
SWODY2
SPC AC 190539

Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1239 AM CDT Tue Aug 19 2025

Valid 201200Z - 211200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
NORTH DAKOTA AND FAR NORTHEAST MONTANA...

...SUMMARY...
Isolated severe thunderstorms are possible on Wednesday in the late
afternoon and early evening across northern North Dakota and far
northeast Montana.

...Northern North Dakota/Far Northeast Montana...
A mid-level ridge, extending from a large high centered on the Four
Corners region, will move eastward across the northern Plains on
Wednesday. At the surface, a cold front will advance southeastward
across southern Saskatchewan and southern Manitoba during the day.
Ahead of the front, an axis of moderate instability is forecast to
develop by afternoon from southwestern Manitoba into east-central
North Dakota. Thunderstorm development will be likely near the front
in far southern Canada, with additional more isolated storms
possible near the instability axis in east-central North Dakota.
Model forecasts suggest that MLCAPE will peak in the 3000 to 4000
J/kg range, with 0-6 km shear around 30 knots. This may be enough
for a marginal severe threat. Hail and isolated severe gusts will be
possible, mainly during the late afternoon and early evening.

..Broyles.. 08/19/2025

$$

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ACUS02 KWNS 191703
SWODY2
SPC AC 191702

Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1202 PM CDT Tue Aug 19 2025

Valid 201200Z - 211200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS FAR
NORTHEAST MONTANA AND PARTS OF NORTHERN NORTH DAKOTA...

...SUMMARY...
Isolated severe thunderstorms are possible on Wednesday evening
across northern North Dakota and far northeast Montana.

...Northeast MT into northern ND...

A strong upper anticyclone will be centered over the Four Corners,
with attendant upper riding extending north/northeast into the
northern Plains. A shortwave upper trough is forecast to develop
east across the Canadian Rockies, and eventually into Saskatchewan
late in the period. This will result in height falls across the
northern Rockies into the northern Plains generally after 00z. As
this occurs, mid/upper westerly flow will increase. Modestly
deepening low pressure over eastern MT likely will result in
increasing southerly low-level flow ahead of a
southeastward-advancing cold front moving across the region from
late afternoon into the nighttime hours.

A narrow corridor of rich boundary layer moisture will exist across
western ND ahead of the front. Steep lapse rates will support
1500-3000 J/kg MLCAPE values. However, capping will likely suppress
diurnal convection. As strong ascent accompanies the approach of the
surface front and upper trough during the evening/nighttime hours,
isolated convection is possible. A marginal wind/hail risk could
accompany any stronger sustained storms near the advancing cold
front.

..Leitman.. 08/19/2025

$$

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ACUS02 KWNS 200557
SWODY2
SPC AC 200556

Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1256 AM CDT Wed Aug 20 2025

Valid 211200Z - 221200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR THE
CENTRAL/EASTERN DAKOTAS INTO PARTS OF MINNESOTA...

...SUMMARY...
An isolated severe threat is expected to develop Thursday into
Thursday night over parts of the Dakotas into Minnesota, with severe
gusts and hail possible.

...Northern Plains into parts of MN...
A mid/upper-level shortwave trough is forecast to evolve into a
deep-layer cyclone as it moves eastward across parts of the Canadian
Prairies on Thursday. A trailing cold front will move through the
Dakotas and northwest MN, with a weak frontal wave potentially
developing across SD. Diurnal heating of a relatively moist airmass
will result in moderate to locally strong destabilization by late
afternoon.

An embedded mid/upper-level shortwave trough and associated remnant
convection is expected to move across MB/ND and northern MN early in
the day. In the wake of this shortwave, large-scale ascent is
expected to be generally weak until later Thursday night, resulting
in uncertainty regarding afternoon/evening storm development.
Isolated storm development cannot be ruled out near the front, and
potentially near the weak surface low across SD. An increase in
storm coverage is expected late Thursday night, as somewhat stronger
midlevel height falls and upper-level difluence overspread the
region.

The strongest mid/upper-level flow will tend to lag behind the
front, but deep-layer shear will still be sufficient for some storm organization, including conditional supercell potential. The
Marginal Risk has been maintained with this outlook, but greater
severe probabilities may eventually be needed, depending on trends
regarding storm coverage and timing from parts of the Dakotas into
northwest MN.

Other strong storms may develop Thursday night across parts of the
northern High Plains, within a favorably sheared post-frontal
regime. Severe probabilities may eventually need to be expanded
westward, if confidence increases in a favored post-frontal
corridor.

...Coastal NC...
The center of Hurricane Erin is forecast by NHC to remain well
offshore of coastal NC on Thursday as it begins moving
northeastward. However, the western periphery of Erin's large wind
field will result in rather strong deep-layer northerly flow across
the Outer Banks and vicinity. If modest diurnal heating can occur,
then showers and possibly a few weak storms may develop during the
afternoon, though it is uncertain if any such development would be
sufficiently vigorous to support convectively augmented gusts.

...Parts of the Southeast/southern Appalachians...
Scattered thunderstorms are forecast to develop across parts of the
Southeast and southern Appalachians vicinity Thursday afternoon.
Deep-layer shear will remain quite weak, but northerly low-midlevel
flow may support one or more southward-moving clusters. Poor
midlevel lapse rates will tend to limit updraft intensity, and the
organized severe threat appears low, but localized tree damage could
accompany these storms during the afternoon and early evening.

...Arizona...
Thunderstorms are expected to develop Thursday afternoon and evening
across parts of AZ, initially near the higher terrain. Isolated
strong gusts could accompany these storms. With an amplified
upper-level ridge anchored near the Four Corners, midlevel flow will
generally be easterly across central/southern AZ. The easterly
steering flow and a very hot and well-mixed environment could
support a threat of strong outflow gusts into the lower elevations,
though it is uncertain if storm coverage will be sufficient for
larger-scale outflow development and more than very isolated
damaging-wind potential.

..Dean.. 08/20/2025

$$

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ACUS02 KWNS 201657
SWODY2
SPC AC 201655

Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1155 AM CDT Wed Aug 20 2025

Valid 211200Z - 221200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS
OF THE DAKOTAS INTO MINNESOTA...

...SUMMARY...
An isolated severe threat is expected to develop Thursday into
Thursday night over parts of the Dakotas into Minnesota, with severe
gusts and hail possible.

...Northern Plains into Minnesota...

An upper shortwave trough/cyclone will deepen and develop east
across the Canadian Prairies on Thursday. This will result in
dampening of the upper ridge/height falls across the northern Plains
vicinity. Early in the day, a weak shortwave impulse and remnant convection/cloud debris will move across portions of ND/MN.
Meanwhile, a cold front will develop east/southeast across the
Dakotas into northern MN through early Friday.

A corridor of rich boundary layer moisture with dewpoints generally
in the mid 60s to near 70 F will be in place ahead of the cold
front. However, stronger forcing for ascent will not arrive until
later in the evening/overnight. It is unclear how much diurnal
convection may develop due to weaker forcing and capping. If a storm
can form ahead of the front during the afternoon, a corridor of
2000-3000 J/kg MLCAPE will be in place amid 30+ kt effective shear.
Strong gusts and hail would be possible with cellular activity
through early evening.

More likely, convection will develop during the evening/nighttime
hours across parts of the region. Initial storms may develop in the post-frontal upslope regime across eastern WY/western SD and develop
east across SD overnight. It is unclear how intense these initial
storms further west will be, and probabilities may need to be
expanded westward in subsequent outlooks if confidence increases.
Once storms interact with better moisture/instability further east,
isolated severe gusts or marginal hail will be possible.

..Leitman.. 08/20/2025

$$

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