544
ACUS03 KWNS 070727
SWODY3
SPC AC 070726

Day 3 Convective Outlook
NWS Storm Prediction Center Norman OK
0226 AM CDT Mon Jul 07 2025

Valid 091200Z - 101200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS
OF THE NORTHERN PLAINS AND THE CAROLINAS INTO THE MID ATLANTIC...

...SUMMARY...
At least isolated severe storms are possible in the northern Plains
on Wednesday, with large hail the main threat, and an instance of
very large hail cannot be ruled out. Isolated damaging gusts are
also possible across parts of the eastern U.S.

...Synopsis...
An upper ridge will persist over the Southwest as a low-amplitude
mid-level trough approaches the Northeast on Wednesday. A pronounced
mid-level impulse will crest the upper ridge and traverse the
northern Rockies, supporting the rapid onset of surface lee
troughing across the northern Plains. Here, rich low-level moisture
will advect northward beneath colder temperatures aloft to support
strong buoyancy amid modest vertical wind shear. At least isolated
severe storms are likely. Isolated strong thunderstorms may also
develop along portions of the East Coast.

...Northern Plains...
A conditional severe threat is expected to develop ahead of the
surface trough on Wednesday afternoon. Dewpoints into the 60s F will
be overspread by 8+ C/km mid-level lapse rates by afternoon peak
heating, yielding 3500-4500 J/kg MLCAPE. Modest northwesterly 500 mb
flow rotating around the ridge will overspread the aforementioned
southerly flow, resulting in modestly elongated hodographs and 30
kts of effective bulk shear. A dryline feature will advance eastward
during the afternoon, serving as a primary lifting mechanism in
tandem with strong surface heating given weak upper support.
Isolated supercell development is possible, accompanied by a severe
wind/hail risk. Given the degree of buoyancy in place, a conditional
risk of 2+ inch hail exists should a supercell develop and become
sustained. Weak upper support and lack of confidence for greater
storm coverage is the primary limiting factor for higher severe
probabilities at this time.

...Portions of the Carolinas into the Mid Atlantic...
Scattered thunderstorms should develop atop a moist, weakly capped
boundary layer by early afternoon. Though vertical wind shear should
be weak and lapse rates will be poor, surface heating of the moist
boundary layer will support 2000-3000 J/kg of tall/thin CAPE. As
such, the stronger storms may produce wet downbursts and subsequent
isolated damaging gusts.

..Squitieri.. 07/07/2025

$$