SPC MD 357

MD 0357 CONCERNING SEVERE POTENTIAL…WATCH LIKELY FOR PORTIONS OF CENTRAL/SOUTHERN ILLINOIS AND WESTERN INDIANA

Mesoscale Discussion 0357
NWS Storm Prediction Center Norman OK
0243 PM CDT Wed Apr 02 2025

Areas affected...Portions of central/southern Illinois and western
Indiana

Concerning...Severe potential...Watch likely 

Valid 021943Z - 022145Z

Probability of Watch Issuance...80 percent

SUMMARY...Storms are expected to increase in intensity and move into
the area this afternoon posing a threat of tornadoes, hail, and
damaging wind.  There is some uncertainty on the exact timing of the
threat, but a tornado watch is likely in the next two hours.

DISCUSSION...With an ejecting midlevel trough and associated surface
cyclone to the northwest of the region, the warm front has continued
to lift northward this afternoon.  As a result, filtered insolation
and moisture advection have resulted in destabilization, with the
latest mesoanalysis indicating 1500 J/kg of MLCAPE nosing into
central Illinois.  Given the strong low-level flow (75 kts at 2-km
AGL per 19Z ILX sounding and recent VWPs) and shear, storms will
pose a threat of strong tornadoes and severe winds.

Convective initiation within the warm sector does not appear
imminent, so storms will likely move into the area from the
south-southwest, where storms have rapidly intensified across
Missouri in the past hour.  Convective mode will likely be messy
with a large component of deep-layer shear aligned with the primary
axis of convection oriented south-southwest to north-northeast. 
With time, there is some expectation that storms will cluster and
grow upscale resulting in an increasing severe wind threat. 

Given the threat of significant severe weather (all hazards) during
the late afternoon and evening hours, a tornado watch is likely in
the next two hours.

..Jirak/Guyer.. 04/02/2025

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

ATTN...WFO...IWX...IND...PAH...LOT...ILX...LSX...

LAT...LON   39919026 40678956 40808827 40718694 40148655 39098682
            38638716 38218766 37978795 37958853 38298920 38508983
            39919026 

MOST PROBABLE PEAK TORNADO INTENSITY...140-170 MPH
MOST PROBABLE PEAK WIND GUST...75-90 MPH
MOST PROBABLE PEAK HAIL SIZE...1.50-2.50 IN

Read more