351
ACUS11 KWNS 240556
SWOMCD
SPC MCD 240556
KYZ000-INZ000-ILZ000-240830-

Mesoscale Discussion 2099
NWS Storm Prediction Center Norman OK
1256 AM CDT Tue Sep 24 2024

Areas affected...Kentucky...Far Southeast Illinois...Far Southern
Indiana

Concerning...Severe potential...Watch unlikely

Valid 240556Z - 240830Z

Probability of Watch Issuance...5 percent

SUMMARY...An isolated severe threat will continue across the Ohio
Valley over the next several hours. A severe wind gust, or a brief
tornado will be possible. The severe threat is expected to remain
marginal, and watch issuance appears unlikely.

DISCUSSION...The latest water vapor imagery shows a mid-level
shortwave trough moving into the Ozarks. A distinct vorticity max is
evident on mosaic radar as an MCV in far southeast Missouri.
Thunderstorms are ongoing from near the MCV extending northeastward
into southern Illinois and southern Indiana, near a maximum in warm
air advection. Surface dewpoints in the lower Ohio Valley are in the
upper 60s F, and the RAP has MLCAPE up to 750 J/kg in the vicinity
of Evansville, Indiana. The WSR-88D VWP at Louisville has 0-6 km
shear around 45 knots, with 0-3 km storm-relative helicity around
175 m2/s2. Directional shear is confined mostly to the lowest 1
kilometer. This wind profile should be enough for transient
supercell structure. Any tornado that forms would likely be brief.
An isolated severe gust will also be possible, especially if any of
the cells can obtain a bowing structure.

..Broyles/Smith.. 09/24/2024

...Please see www.spc.noaa.gov for graphic product...

ATTN...WFO...ILN...LMK...IND...PAH...

LAT...LON   38588746 37968858 37498899 37138902 36918858 36898743
            36918552 37288477 38038439 38578496 38708635 38588746