116  
ACUS11 KWNS 131528  
SWOMCD  
SPC MCD 131528  
ILZ000-IAZ000-MOZ000-131800-  
 
MESOSCALE DISCUSSION 1967  
NWS STORM PREDICTION CENTER NORMAN OK  
1028 AM CDT THU AUG 13 2026  
 
AREAS AFFECTED...CENTRAL ILLINOIS  
 
CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE  
 
VALID 131528Z - 131800Z  
 
PROBABILITY OF WATCH ISSUANCE...60 PERCENT  
 
SUMMARY...STRONG TO SEVERE STORMS WILL MOVE OUT OF IOWA AND INTO  
ILLINOIS THIS MORNING. DEPENDING ON STORM TRENDS, A WATCH COULD BE  
NEEDED FOR SCATTERED DAMAGING GUSTS.  
 
DISCUSSION...A WELL-DEFINED MCS CONTINUES TO PUSH ACROSS EASTERN IA,  
WITH PRIMARY CONVECTIVE LINE OVER SOUTHEAST IA AND INTO FAR  
NORTHEAST MO. STORM TRENDS SUGGEST SOME WEAKENING HAS OCCURRED OVER  
THE PAST FEW HOURS, THOUGH LOCALLY STRONG GUSTS HAVE BEEN REPORTED  
OVER IA.  
 
DOWNSTREAM OF THIS SYSTEM, COOLER/MORE STABLE AIR EXISTS OVER  
NORTHERN IL AND IN, WITH AN INSTABILITY GRADIENT EXTENDING FROM  
CENTRAL IL INTO SOUTHERN IN. THIS INSTABILITY MAY DEVELOP VERY  
SLOWLY NORTHWARD DURING THE AFTERNOON. WIND SHEAR IS A BIT MARGINAL  
FOR SUSTAINED STORMS, BUT MIDLEVEL WESTERLIES AROUND 30 KT, COMBINED  
WITH STRENGTHENING LOW-LEVEL WINDS DURING THE AFTERNOON MAY PROVIDE  
A SLIGHTLY BETTER ENVIRONMENT.  
 
..JEWELL.. 08/13/2026  
   
..PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT  
 
ATTN...WFO...LOT...ILX...LSX...DVN...  
 
LAT...LON 41469160 41148780 40908759 40178763 39768794 39808884  
40129059 40309148 40479187 40669197 41139167 41469160  
 
MOST PROBABLE PEAK WIND GUST...55-70 MPH  
MOST PROBABLE PEAK HAIL SIZE...UP TO 1.25 IN  
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