486
ACUS11 KWNS 031647
SWOMCD
SPC MCD 031646
OHZ000-KYZ000-INZ000-ILZ000-031915-

Mesoscale Discussion 1519
NWS Storm Prediction Center Norman OK
1146 AM CDT Wed Jul 03 2024

Areas affected...Far Southeast IL...Northern/Western KY...Southern
IN...Southwest/Central OH

Concerning...Severe potential...Watch possible

Valid 031646Z - 031915Z

Probability of Watch Issuance...40 percent

SUMMARY...Thunderstorms coverage is expected to increase across the
OH Valley this afternoon. Damaging gusts are possible with any
water-loaded downbursts or short-duration bowing segments, but the
disorganized convective mode could limit the need for a watch.

DISCUSSION...Surface temperatures have already climbed into the mid
80s within a fairly narrow corridor ahead of the approaching cold
front but west of the influence of the East Coast ridging (roughly
from southeast IL northeastward along the OH River vicinity into
western OH). Dewpoints are in the low 70s within this corridor, and
the resulting warm and moist conditions are promoting quick airmass
destabilization despite generally pool mid-level lapse rates. This
destabilization is evidenced by cumulus development throughout much
of the region. Relatively warm temperatures aloft and poor lapse
rates combined with boundary-layer mixing will likely temper the
overall instability, with MLCAPE expected to remain around 1000 J/kg
areawide. Given that the stronger mid-level flow is displaced north
of the region, vertical shear will be modest as well, with 0-6 km
bulk shear around 25 to 30 kt.

General expectation is for thunderstorm coverage to increase this
afternoon within this corridor ahead of the front, with a
multicellular mode dominating. Primary severe risk is forecast to be
damaging gusts attendant to wet downbursts. There is some chance for
bowing segments in areas where storm development occurs in close
proximity and cold pools are able to amalgamate. Damaging gusts
would be possible with these forward propagating segments as well.
Convective trends will be monitored, but with a disorganized
multicellular mode anticipated, a watch is not likely.

..Mosier/Gleason.. 07/03/2024

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

ATTN...WFO...CLE...JKL...ILN...LMK...IWX...IND...PAH...ILX...

LAT...LON   39018760 40918367 40658237 39138283 37548541 36648847
            37968877 39018760