271
ACUS01 KWNS 230525
SWODY1
SPC AC 230523

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1223 AM CDT Mon Sep 23 2024

Valid 231200Z - 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 from the Ozarks
into parts of the Tennessee and lower Ohio Valleys.

...Ozarks to TN/OH Valley Region...

Northern-stream short-wave trough is forecast to dig into the
northern Plains later this afternoon, which will encourage the
positive-tilt trough over the central Plains to eject east, and
deamplify over the MS Valley late in the period. This evolution is
expected to aid weak surface wave/low development along the synoptic
front, mostly likely over northern AR early in the period. Latest
model guidance suggests this weak feature will track northeast into
southern IN by 24/12z. While the surface front is not particularly
sharp, this boundary will serve as the focus for scattered
convection through the period. Pre frontal boundary-layer heating
will prove instrumental in destabilization as mid-level lapse rates
should remain weak through the period. Latest NAM suggests 0-3km
lapse rates will steepen across eastern AR into western KY by early
afternoon, which will result in MLCAPE in excess of 1000 J/kg,
coincident with modest 0-6km bulk shear. Forecast soundings favor
multi cell updrafts with some organizational potential, as effective
shear will be on the order of 30kt along this pre frontal corridor.
At this time it appears most updrafts will struggle to generate more
than marginally strong gusts, or perhaps some hail approaching 1
inch. Most robust updrafts should develop by late morning and
continue into the early-evening hours before nocturnal cooling
lessens buoyancy.

..Darrow/Thornton.. 09/23/2024

$$