258
ACUS11 KWNS 201845
SWOMCD
SPC MCD 201844 COR
INZ000-ILZ000-202030-
MESOSCALE DISCUSSION 0905
NWS STORM PREDICTION CENTER NORMAN OK
0144 PM CDT TUE MAY 20 2025
AREAS AFFECTED...MUCH OF CENTRAL ILLINOIS AND ADJACENT WEST CENTRAL
INDIANA
CONCERNING...SEVERE POTENTIAL...WATCH LIKELY
VALID 201844Z - 202030Z
CORRECTED FOR TYPO
PROBABILITY OF WATCH ISSUANCE...95 PERCENT
SUMMARY...THUNDERSTORM DEVELOPMENT WILL CONTINUE TO GRADUALLY
INTENSIFY THROUGH 2-4 PM CDT, POSING INCREASING RISK FOR SEVERE
WEATHER.
DISCUSSION...LOW-LEVEL CONVERGENCE AND BOUNDARY-LAYER
DESTABILIZATION IS BECOMING MAXIMIZED ACROSS MUCH OF CENTRAL
ILLINOIS, WITHIN THE WARM SECTOR TO THE SOUTHEAST OF THE PRIMARY
SURFACE LOW CENTER NOW OVER SOUTHEASTERN IOWA. THIS WILL CONTINUE
TO BE AIDED BY MID-LEVEL COOLING AND FORCING FOR ASCENT ASSOCIATED
WITH A STILL WELL-DEFINED CYCLONIC VORTICITY CENTER TO THE
WEST-NORTHWEST OF QUINCY IL, WHICH IS FORECAST TO CONTINUE A SLOW
NORTHEASTWARD AND EASTWARD MIGRATION ACROSS THE MIDWEST THROUGH LATE
AFTERNOON.
THERMODYNAMIC PROFILES, PARTICULARLY CENTERED ACROSS AND SOUTHEAST
OF THE SPRINGFIELD AREA, APPEAR CHARACTERIZED BY RATHER STEEP
LOWER/MID-TROPOSPHERIC LAPSE RATES, WITH MIXED-LAYER CAPE INCREASING
IN EXCESS OF 1000 J/KG. AS RESIDUAL INHIBITION ASSOCIATED WITH THE
REMNANTS OF ELEVATED MIXED-LAYER AIR CONTINUES TO ERODE, THE
ENVIRONMENT IS BECOMING SUPPORTIVE OF ORGANIZED CONVECTION
NEAR/BENEATH THE EXIT REGION OF A STRONG MID/UPPER JET. THIS MAY
INCLUDE A FEW DISCRETE SUPERCELLS AND PERHAPS AN ORGANIZING CLUSTER
WITH POTENTIAL TO PRODUCE SEVERE HAIL AND DAMAGING WIND GUSTS.
MODEST CLOCKWISE-CURVED LOW-LEVEL HODOGRAPHS MAY ALSO SUPPORT A RISK
FOR TORNADOES, PARTICULARLY WITH THE MORE DISCRETE STORMS.
..KERR/HART.. 05/20/2025
..PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT
ATTN...WFO...IND...LOT...ILX...LSX...DVN...
LAT...LON 41188923 40728835 38858721 38988952 39868947 40358973
41188923
MOST PROBABLE PEAK TORNADO INTENSITY...100-130 MPH
MOST PROBABLE PEAK WIND GUST...55-70 MPH
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