SPC Aug 24, 2025 0600 UTC Day 1 Convective Outlook

LIVE MAP (ABOVE) ... SPC 1200Z Day 1 Outlook


Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1240 AM CDT Sun Aug 24 2025

Valid 241200Z - 251200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS
OF NEW YORK/PENNSYLVANIA AND FROM EASTERN COLORADO TO WESTERN
OKLAHOMA...

...SUMMARY...
A few storms may reach severe thresholds from eastern Colorado into
western Oklahoma this afternoon and evening. Scattered strong-severe
storms are possible across portions of Pennsylvania and New York.
Hail or wind are the expected risks.

...NY/PA...

Early-morning satellite imagery depicts a strong upper trough over
ON/Great Lakes, shifting east-southeast in line with latest model
guidance. Associated surface front is forecast to advance into
western NY/PA by early afternoon before shifting into central
portions of these states by 25/00z. Modest boundary-layer heating is
expected to aid destabilization ahead of the front and convective
temperatures are expected to be breached around 20-21z; although,
deep-layer lapse rates are not expected to be particularly steep
(0-6km values around 6.5 C/km). While CAMs support this with
scattered frontal convection developing around mid afternoon. This
activity could generate locally strong winds, and perhaps some hail.
Main risk will be during the mid afternoon into early evening before
the boundary layer cools after sunset.

...Eastern CO to western OK...

Eastern periphery of Great Basin high will flatten as northwesterly
flow becomes firmly established along the back side of Great
Lakes/OH Valley trough. At the surface, pronounced surface
anticyclone will settle into the northern Plains, ultimately forcing
the leading edge of more continental air into the southern Plains by
the end of the period. Net take is a corridor of low-level warm
advection will become established from southern WY into western OK -
coincident with northwest-southeast frontal orientation. It appears
a few weak disturbances will top the ridge and dig southeast toward
the southern Plains. Each of these features should encourage a
response in the LLJ, which will aid convective development. Elevated
convection may be ongoing at the start of the period across western
NE into northwest KS. A substantial cluster/MCS should propagate
southeast with renewed development later in the period. Rain-cooled
boundary layer will ensure stronger heating is focused across
southeast CO into western OK. Primary concern for isolated severe
will be near this zone of stronger heating/instability. Hail and
wind may accompany this more robust convection.

..Darrow/Weinman.. 08/24/2025


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SPC Aug 24, 2025 0100 UTC Day 1 Convective Outlook

LIVE MAP (ABOVE) ... SPC 0100Z Day 1 Outlook


Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0740 PM CDT Sat Aug 23 2025

Valid 240100Z - 241200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ALONG THE
CENTRAL ROCKIES FRONT RANGE...

...SUMMARY...
Isolated severe thunderstorms remain possible near the
Colorado/Wyoming Front Range and central High Plains this evening.

...01z Update...

Great Basin upper ridge is gradually building north across the
Interior West early this evening. As a result, northwesterly flow
remains firmly established across eastern WY/CO. Scattered
convection has developed beneath this feature with the eastern-most
thunderstorms noted along the CO Front Range. Latest diagnostic data
continues to depict a narrow corridor of modest instability along
the Front Range from southeast WY into northeast NM. A few robust
thunderstorms are noted along this corridor but MRMS data suggests
any hail with this activity is likely marginally severe at best.
Will maintain MRGL Risk for isolated-scattered thunderstorms this
evening as cloud-layer shear is more than strong enough for
organized updrafts.

Southeast Lower Michigan: Scattered thunderstorms have developed
along the cold front across southern ON into southeast MI. While
gusty winds, and perhaps some marginally severe hail, may be noted
with these storms for the next hour or so, this activity will
quickly shift into ON. Severe probabilities will not be introduced
for these reasons.

..Darrow.. 08/24/2025


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SPC Aug 23, 2025 1630 UTC Day 1 Convective Outlook

LIVE MAP (ABOVE) ... SPC 1630Z Day 1 Outlook


Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1122 AM CDT Sat Aug 23 2025

Valid 231630Z - 241200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE COLORADO/WYOMING FRONT RANGE AND ADJACENT CENTRAL HIGH PLAINS...

...SUMMARY...
Isolated severe thunderstorms appear possible near the
Colorado/Wyoming Front Range and central High Plains this afternoon
and evening.

...Front Range/Central High Plains...
A mid/upper-level anticyclone centered over the Southwest and Four
Corners regions will move little today, with ridging extending
northward across much of the Great Basin and Northwest. Modestly
enhanced northwesterly mid-level flow will exist today across the
central Rockies and adjacent High Plains. A moist post-frontal
airmass will remain in place across these areas, with surface
dewpoints generally in the mid to upper 50s. Low cloud cover remains
prevalent across the central High Plains late this morning, which
should continue to hinder destabilization to some extent. Even so,
gradual thunderstorm development should eventually occur over the
higher terrain by late afternoon as persistent low-level upslope
flow aids parcels in reaching their LFCs. This activity should
spread generally south-southeastward through the evening along/near
the I-25 corridor, while posing an isolated threat for mainly hail
due to a combination of modestly steepened lapse rates aloft,
sufficient deep-layer shear, and weak to moderate MLCAPE. Occasional
strong/gusty winds may also occur.

...Great Lakes/Midwest...
Isolated thunderstorms should develop along a cold front this
afternoon as it advances eastward across part of the Great
Lakes/Midwest. Warm low/mid-level temperatures in the presence of
generally low/mid 60s surface dewpoints should limit buoyancy and
updraft strength, likely keeping the overall severe potential low.

..Gleason/Moore.. 08/23/2025


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SPC Aug 23, 2025 1300 UTC Day 1 Convective Outlook

LIVE MAP (ABOVE) ... SPC 1300Z Day 1 Outlook


Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0746 AM CDT Sat Aug 23 2025

Valid 231300Z - 241200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS THE FRONT
RANGE/CENTRAL HIGH PLAINS...

...SUMMARY...
Isolated severe storms are possible near the Colorado/Wyoming Front
Range and central High Plains this afternoon and evening.

...Front Range/Central High Plains...
Multiple subtle upper ridge-peripheral impulses and a belt of
moderately strong northwesterly winds aloft will influence the
region as low-level upslope flow increases late today within the
post-frontal environment. At least widely scattered thunderstorm
development is expected initially over the mountains, with
subsequent intensification as storms develop east-southeastward into
a moderately unstable air mass, with buoyancy maximized
near/immediately east of the urban corridor/I-25. Steep mid-level
lapse rates and 40+ kt effective shear will support the possibility
of isolated supercells capable of large hail and some locally
stronger wind gusts through early evening.

...Midwest/Great Lakes...
A few showers and thunderstorms will likely develop along a cold
front as it moves across the Great Lakes/Midwest this afternoon.
Warm 700mb temperatures in the presence of only low 60s dewpoints
will limit overall buoyancy and updraft strength, likely keeping
severe-storm potential minimal.

..Guyer/Kerr.. 08/23/2025


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