827
ACUS01 KWNS 190547
SWODY1
SPC AC 190545

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1245 AM CDT Sat Jul 19 2025

Valid 191200Z - 201200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS IN PARTS OF THE
NORTHERN/CENTRAL GREAT PLAINS...MIDWEST...AND VA VICINITY...

...SUMMARY...
Scattered large to very large hail and severe gusts are possible
across the northern/central Great Plains during the late afternoon
and evening. Scattered damaging winds are possible across parts of
the Midwest and the Lower Mid-Atlantic States into this afternoon.
Low-probability tornado potential is also evident in the Midwest and
parts of the Great Plains.

...Northern/central Great Plains...
A favorable setup for discrete supercells is anticipated along a lee
trough from the WY/NE border into eastern MT and far western ND.
While rich boundary-layer moisture will remain confined across
southern NE, a ribbon of increasing moisture will be advected
north-northwest beneath a pronounced EML. A shortwave trough will
eject along the Canadian border across the Northwest. An attendant
belt of 40-45 kt mid-level westerlies will overspread much of MT
into ND, with a separate belt of confluent westerlies across
southeast WY through NE. Deep-layer shear profiles will be conducive
to discrete supercells as initial storms develop during the mid to
late afternoon, with large to very hail possible. Signals for
greater convective coverage along the MT/ND border and in the
western NE vicinity may support a greater than isolated severe gust
threat. With a deeper and hotter boundary layer with southward
extent into KS, upscale growth into a forward-propagating cluster
eastward along the NE/KS border is possible this evening.

...Midwest...
An MCS will likely be ongoing at 12Z across IA, with a separate
cluster of elevated convection possible farther northeast in WI. A
downstream split in severe potential may occur as the MCS likely
persists and evolves southeastward. The WI activity may progress and
intensify across Lower MI by afternoon, where deep-layer shear will
be stronger but instability weaker. Scattered damaging winds and
marginal severe hail should be the main hazards. The IA MCS should
progress along the northwest/southeast-oriented MLCAPE gradient
towards the Lower OH Valley. Most CAMs struggle to greatly intensify
this MCS, perhaps owing to warming mid-level temperatures modulating
instability. Scattered damaging wind swaths, with some hail risk
along the southwest flank of the MCS, may occur in the morning, but
will most likely peak into the afternoon.

...VA to northern NC...
A similar setup to Friday afternoon is anticipated, but perhaps
shifted slightly farther north. Ample buoyancy is again expected
across the Carolina Coastal Plain into southern VA with a gradient
in MLCAPE shifted northward in the Mid-Atlantic States. Around 20-kt
500-mb westerlies will support weakly organized multicell clusters
as scattered to numerous storms develop through the afternoon.
Sporadic strong gusts producing damaging winds are possible.

..Grams/Wendt.. 07/19/2025

$$