269  
ACUS11 KWNS 032159  
SWOMCD  
SPC MCD 032159  
INZ000-ILZ000-040000-  
 
MESOSCALE DISCUSSION 0344  
NWS STORM PREDICTION CENTER NORMAN OK  
0459 PM CDT FRI APR 03 2026  
 
AREAS AFFECTED...CENTRAL PORTIONS OF ILLINOIS INTO CENTRAL AND  
NORTHWEST INDIANA  
 
CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE  
 
VALID 032159Z - 040000Z  
 
PROBABILITY OF WATCH ISSUANCE...60 PERCENT  
 
SUMMARY...THE SEVERE THREAT MAY INCREASE INTO THE EVENING HOURS,  
THOUGH THE OVERALL INTENSITY AND COVERAGE OF STORMS REMAINS  
UNCERTAIN AT THE MOMENT.  
 
DISCUSSION...MULTICELLS AND TRANSIENT SUPERCELLS PERSIST ALONG AN  
EAST-TO-WEST ORIENTED BAROCLINIC ZONE ACROSS CENTRAL IL/IN. THESE  
STORMS ARE DEVELOPING AMID A MOIST BOUNDARY LAYER, CHARACTERIZED BY  
UPPER 60S F DEWPOINTS AMID SMALL T/TD SPREADS, WITH OVER 1500 J/KG  
MLCAPE PRESENT. THE UPPER TROUGH IS CURRENTLY DISPLACED RELATIVELY  
FAR TO THE WEST, SO SHORTER TERM FORCING MECHANISMS ARE  
PREDOMINANTLY FROM STRONGER SURFACE HEATING, AND THE ILX/IND VADS  
CURRENTLY DEPICT SHORT AND MODESTLY CURVED HODOGRAPHS. THE CURRENT  
THINKING IS THAT STORMS SHOULD REMAIN AT THEIR CURRENT DEGREE OF  
ORGANIZATION AND INTENSITY FOR AT LEAST THE NEXT COUPLE OF HOURS.  
TRANSIENT CIRCULATIONS POTENTIALLY SUPPORTING ISOLATED, BRIEF  
TORNADOES IS THE MOST IMMEDIATE THREAT.  
 
A FEW HOURS FROM NOW, INTO THE EVENING HOURS, THE GRADUAL APPROACH  
OF THE UPPER TROUGH WILL SUPPORT A SUBSTANTIAL STRENGTHENING OF THE  
850 MB FLOW (I.E. SOUTHERLY LOW-LEVEL JET), ESPECIALLY IN THE 00-06Z  
TIME FRAME. SHOULD DISCRETE, SURFACE BASED STORMS PERSIST IN THIS  
TIME FRAME, IT IS PLAUSIBLE THAT APPRECIABLE STRENGTHENING AND  
ORGANIZATION OF SUPERCELL STRUCTURES WITH SUSTAINED LOW-LEVEL  
MESOCYCLONES MAY BE ACHIEVED. SUCH STORMS MAY POSE A LOCALLY GREATER  
TORNADO THREAT IN ADDITION TO SEVERE WIND/HAIL. HOWEVER, SUCH A  
THREAT IS DEPENDENT ON STORMS REMAINING SURFACE BASED, WITH BOUNDARY  
LAYER STABILIZATION ONLY GRADUALLY TAKING PLACE. AS SUCH,  
UNCERTAINTY REMAINS. HOWEVER, CONVECTIVE TRENDS WILL CONTINUE TO BE  
MONITORED THROUGH THE EVENING HOURS AS THE LOW-LEVEL JET  
INTENSIFIES.  
 
..SQUITIERI/SMITH.. 04/03/2026  
   
..PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT  
 
ATTN...WFO...IWX...IND...LOT...ILX...LSX...DVN...  
 
LAT...LON 41219007 41558879 41278654 40818576 40368573 39968598  
39798676 39768817 39708945 39729011 39979053 40909034  
41219007  
 
MOST PROBABLE PEAK TORNADO INTENSITY...85-115 MPH  
MOST PROBABLE PEAK WIND GUST...55-70 MPH  
MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN  
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