068  
ACUS11 KWNS 161908  
SWOMCD  
SPC MCD 161908  
ILZ000-162115-  
 
MESOSCALE DISCUSSION 1687  
NWS STORM PREDICTION CENTER NORMAN OK  
0208 PM CDT WED JUL 16 2025  
 
AREAS AFFECTED...NORTHERN/CENTRAL IL  
 
CONCERNING...SEVERE THUNDERSTORM WATCH 518...  
 
VALID 161908Z - 162115Z  
 
THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 518  
CONTINUES.  
 
SUMMARY...STRONG TO SEVERE THUNDERSTORMS WILL CONTINUE FOR THE NEXT  
SEVERAL HOURS ACROSS NORTHERN AND CENTRAL IL.  
 
DISCUSSION...STRONG TO SEVERE THUNDERSTORMS HAVE DEVELOPED ALONG A  
WIND SHIFT MOVING EASTWARD ACROSS NORTHERN/CENTRAL IL. TEMPERATURES  
ALONG AND AHEAD OF THIS WIND SHIFT HAVE RISEN INTO THE UPPER 80S/LOW  
90S AMID DEWPOINTS IN THE MID 70S. DESPITE RELATIVELY POOR MID-LEVEL  
LAPSE RATES, THESE WARM AND MOIST SURFACE CONDITIONS SUPPORT MLCAPE  
AROUND 2500 J/KG.  
 
THE STRONGEST STORMS ARE CURRENTLY ONGOING ACROSS NORTHERN IL, WHERE  
STRONGER MID-LEVEL FLOW EXISTS. THESE STORMS WILL LIKELY PERSIST AS  
THEY MOVE EASTWARD OVER THE NEXT SEVERAL HOURS. HAIL AND DAMAGING  
GUSTS ARE POSSIBLE WITH ANY OF THE MORE ROBUST UPDRAFTS. FARTHER  
SOUTH, UPDRAFT STRENGTH AND DURATION MAY BE LIMITED BY THE LACK OF  
STRONGER SHEAR. EVEN SO, GIVEN AMPLE LOW-LEVEL MOISTURE AND STRONG  
TO VERY STRONG BUOYANCY IN PLACE, UPDRAFTS COULD STILL BE STRONG  
ENOUGH TO PRODUCE WATER-LOADED STRONG DOWNBURSTS.  
 
..MOSIER.. 07/16/2025  
   
..PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT  
 
ATTN...WFO...LOT...ILX...LSX...DVN...  
 
LAT...LON 42118909 42428853 42308782 41638767 40198852 39168996  
39539062 40658968 42118909  
 
MOST PROBABLE PEAK TORNADO INTENSITY...UP TO 95 MPH  
MOST PROBABLE PEAK WIND GUST...55-70 MPH  
MOST PROBABLE PEAK HAIL SIZE...UP TO 1.25 IN  
CLICK HERE TO GO TO PREVIOUS BULLETINS.
The Nexlab SPC Page
Main Text Page