953
ACUS02 KWNS 291712
SWODY2
SPC AC 291710

Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1210 PM CDT Sun Jun 29 2025

Valid 301200Z - 011200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE
MIDWEST INTO THE OHIO VALLEY...THE MID-ATLANTIC...AND ALONG THE
CALIFORNIA/OREGON BORDER...

...SUMMARY...
Scattered strong to severe thunderstorms remain possible across
parts of the Ohio Valley, Midwest and the Mid-Atlantic tomorrow
(Monday). A couple of severe thunderstorms also cannot be ruled out
over parts of the Pacific Northwest.

...Synopsis...
A mid-level trough will amplify while traversing the Great Lakes and
Ohio Valley regions, as upper ridging builds over the Plains states
and an upper-level low impinges on the California coastline tomorrow
(Monday). A cold front will accompany the Midwest mid-level trough,
and is poised to progress across the Mid-MS and OH Valley regions
while draping across the southern Plains through the day. In advance
of the cold front, adequate moisture and overall instability will be
present to support at least scattered thunderstorms. Given the
presence of modest vertical wind shear, a few of the storms could
become strong to locally severe. Thunderstorms may also develop
north of a surface low along the CA/OR border, amid an unstable
airmass supportive of scattered strong thunderstorms.

...Midwest into the OH Valley...
Preceding an advancing cold front, diurnal heating of a moist
boundary layer, atop relatively poor mid-level lapse rates, will
result in airmass destabilization and 1500-3000 J/kg SBCAPE by
afternoon. While MLCINH will minimize by late morning, the poor
mid-level lapse rates suggest that CAPE should be constrained to
tall/thin profiles. Furthermore, unidirectional vertical wind
profiles with little strengthening with height, should lead to
mediocre deep-layer shear. While many scattered storms should
develop along the cold front, and ahead in the uncapped warm sector,
most storms should be pulse-cellular to multicellular in nature. A
few of the stronger storms may support wet downbursts capable of
producing localized damaging gusts.

...Mid-Atlantic...
Similar to the Great Lakes/OH Valley vicinity, strong boundary-layer
heating will quickly reduce convective inhibition and support
scattered thunderstorm development amid weak vertical wind shear.
2000+ J/kg of tall/thin SBCAPE will support wet downburst potential,
and a couple of damaging wind gusts are possible.

...Southern Plains...
Scattered thunderstorms should develop by afternoon peak heating
ahead of the trailing cold front over the southern Plains. Surface
temperatures should warm to near 90 F amid low to mid 70s F
dewpoints, yielding as much as 3000-4000 J/kg MLCAPE given modest
mid-level lapse rates. Though vertical wind shear should be
relatively poor, the strong buoyancy in place may compensate to
support wet downbursts and associated isolated severe gusts with the
stronger storms.

...Northern California into Southern Oregon...
Scattered thunderstorms will develop immediately north of a weak
surface low, where localized forcing for ascent will be in place.
These thunderstorms should develop atop a mixed boundary layer that
may deepen to 600-500 mb. Furthermore, the presence of 9+ C/km lapse
rates through the troposphere may promote enough
thermodynamically-driven downward momentum transport to support
isolated strong to severe wind gusts. Point forecast soundings also
depict curved/elongated hodographs, which may support multicells and
transient supercells with a marginal hail threat.

..Squitieri.. 06/29/2025

$$