570
ACUS02 KWNS 301731
SWODY2
SPC AC 301729

Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1229 PM CDT Mon Jun 30 2025

Valid 011200Z - 021200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF
THE MID-ATLANTIC...

...SUMMARY...
Scattered strong to severe storms are possible across parts of the
Mid-Atlantic into the Northeast on Tuesday afternoon/evening. An
isolated severe storm may also occur over parts of the central High
Plains.

...Synopsis...
A mid-level trough will traverse the Northeast as an upper ridge
persists over the central U.S. and a mid-level low meanders over CA
tomorrow (Tuesday). The East Coast mid-level trough will encourage
the eastward advancement of a cold front, which will provide enough
lift for scattered to widespread thunderstorm development across the
Carolinas into the Northeast. Rich low-level moisture preceding the
front will encourage enough buoyancy, amid marginal but adequate
vertical wind shear, to support strong thunderstorms, some of which
could be severe. A couple of strong to severe storms are possible
along the periphery of the upper ridge over parts of the northern
Rockies into the central High Plains.

...Northeast into the Southeast...
As the surface cold front advances eastward across the eastern U.S.,
surface temperatures will warm into the 80s F to near 90 F, amid 70+
F dewpoints from the Southeast to the Mid-Atlantic, boosting SBCAPE
into the 2000-3500 J/kg range by afternoon peak heating. Relatively
poor mid-level lapse rates will limit CAPE to tall/thin profiles.
However, the magnitude of buoyancy, combined with widespread
thunderstorm coverage over a large area, will foster ample
opportunity for at least isolated damaging gusts with wet
downbursts, from the Southeast to New England. A more concentrated
area of damaging gust potential exists over parts of the
Mid_Atlantic, where a Category 2/Slight Risk remains in place. Here,
line segments are expected to organize amid a region of maximum
buoyancy and 30 kts of effective bulk shear, driven by stronger
west-southwesterly mid-level flow grazing the area.

...Portions of the Northern Rockies...
Mid-level monsoonal moisture is forecast to crest the upper ridge
amid modest 500 mb west-southwesterly flow over parts of the
Northern Rockies, where guidance consensus shows PWATs reaching 0.8
inches in spots. High-based thunderstorms will develop by afternoon
peak heating, atop a well-mixed boundary layer extending to 500 mb
via inverted-v thermodynamic profiles. The aforementioned mid-level
moisture, combined with steep tropospheric lapse rates, will support
over 500 J/kg MLCAPE. This buoyancy may support robust enough
updrafts and subsequent storm cores in an environment where ample
evaporative cooling may take place to support isolated severe gusts.

...Central High Plains...
Low-level upslope flow, along with strong diurnal heating, and the
passage of a small impulse embedded in the upper ridge, will all
serve as mechanisms for convective initiation tomorrow afternoon.
Though storms should be isolated, they will develop amid 8 C/km low
and mid-level lapse rates that will boost MLCAPE into the 1500-2500
J/kg range. Modest directional vertical wind shear will support
somewhat curved/elongated hodographs and around 35 kts of effective
bulk shear. As such, a few multicells/transient supercells may
develop and produce isolated severe wind/hail.

..Squitieri.. 06/30/2025

$$