387
ACUS01 KWNS 231644
SWODY1
SPC AC 231643

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1143 AM CDT Mon Sep 23 2024

Valid 231630Z - 241200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM THE OZARKS
TO THE OHIO/TENNESSEE VALLEYS REGION...

...SUMMARY...
Isolated strong to severe thunderstorms are possible this afternoon
into evening from the Ozarks into parts of the Tennessee and lower
Ohio Valleys.

...Ozarks to TN/OH Valleys and southern Appalachians...
A positive-tilt upper trough will influence the region, with a
general increase in relatively strong deep-layer southwesterly
winds. Severe storms are possible this afternoon, particularly and
initially across the Ozarks including far south-central to southeast
Missouri, as well as far northern Arkansas and far southern
Illinois. This will be in vicinity of a weak surface wave and a
northward-shifting warm front as lingering morning convection
along/north of the Ohio River abates and shifts eastward.
Increasingly strong deep-layer winds could support some supercells.
Some hail is possible given the buoyancy/deep-layer wind profiles,
although mid-level lapse rates are not steep. Locally damaging winds
may also occur, with some potential for a tornado or two mainly near
the warm front.

Although uncertainties linger regarding destabilization and the
magnitude of the severe risk later this afternoon, portions of
southeast Missouri and far southern Illinois will continue to be
reevaluated into mid-afternoon (20Z update) for a potential risk
upgrade.

Farther east, isolated to scattered thunderstorms will probably
develop near the ridge tops of the southern Appalachians and
adjacent parts of the Carolinas Piedmont this afternoon. Moist low
levels coupled with heating will result in around 1000 J/kg MLCAPE.
Some modest multicell organization may occur due to adequately
strong upper-level westerly flow, with a few locally damaging wind
gusts a possibility.

..Guyer/Lyons.. 09/23/2024

$$