527
ACUS01 KWNS 081951
SWODY1
SPC AC 081950

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0250 PM CDT Tue Jul 08 2025

Valid 082000Z - 091200Z

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

...SUMMARY...
Scattered severe thunderstorms are expected across the Mid-Atlantic
states. More isolated severe storms are expected across portions of
the Plains into the Mid Mississippi Valley.

...20Z Update...
Minor changes were made to the outlook based on current
observations. Otherwise, the previous forecast reasoning remains
valid.

..Wendt.. 07/08/2025

.PREV DISCUSSION... /ISSUED 1125 AM CDT Tue Jul 08 2025/

...Mid-Atlantic this afternoon/evening...
Strong surface heating is underway within a very moist boundary
layer consisting of generally mid 70s dewpoints.  Regional 12z
soundings, modified for afternoon temperatures and associated
vertical mixing, suggest the potential for MLCAPE near or above 2000
J/kg with minimal convective inhibition.  Larger-scale forcing for
ascent will be modest with a slightly enhanced (~25 kt) belt of
west-southwesterly midlevel flow from the OH Valley to southern New
England, though the primary focus for scattered thunderstorm
development is expected to be a surface trough from the immediate
lee of the Blue Ridge into MA by mid afternoon.  Though midlevel
lapse rates will not be particularly steep, steepening low-level
lapse rates with hot afternoon temperatures in the low-mid 90s will
drive strong downdraft potential (per DCAPE near 1000 J/kg) and the
resultant threat for wind damage with multicell clusters and/or
short line segments.

...Central High Plains to the Ozarks this afternoon/evening...
A weakening outflow boundary from overnight convection is moving
southeastward into southeast MO, and southward into OK, while a
remnant MCV moves eastward over northern MO.  South of the outflow,
clouds and ongoing convection from eastern OK to the MO Bootheel
cast uncertainty on the degree of destabilization this afternoon in
advance of this portion of the outflow.  Farther west, stronger
surface heating/destabilization is expected along and south of the
outflow into OK, but forcing for ascent is in question with gradual
height rises expected aloft.  A weak lee trough could help focus at
least isolated thunderstorm development this afternoon/evening
across the central High Plains, where northwesterly flow
aloft/hodograph length could be sufficient for a high-based
supercell or two.  However, a specific focus for initiation and the
potential for upscale growth are both uncertain given the background
height rises and little forcing for ascent.  Thus, will maintain the
broad MRGL area for a low probability/conditional threat for severe
outflow winds and some hail.

...Northeast WI/Upper MI this afternoon/evening...
A midlevel shortwave trough and weak surface reflection will cross
northern WI and western Upper MI this afternoon, and a few storms
will be possible by mid afternoon from central Upper MI into extreme
northeast WI (in the wake of weak morning convection).
Thermodynamic recovery from weak morning convection and some
enhancement to westerly deep-layer shear suggests the potential for
semi-organized storms/clusters and a low-end threat for wind damage
and hail for a few hours later this afternoon/evening.

$$