274  
ACUS11 KWNS 152252  
SWOMCD  
SPC MCD 152252  
ILZ000-WIZ000-IAZ000-160015-  
 
MESOSCALE DISCUSSION 1956  
NWS STORM PREDICTION CENTER NORMAN OK  
0552 PM CDT FRI AUG 15 2025  
 
AREAS AFFECTED...PORTIONS OF EASTERN/SOUTHEASTERN IOWA INTO  
NORTHWESTERN ILLINOIS  
 
CONCERNING...SEVERE THUNDERSTORM WATCH 590...  
 
VALID 152252Z - 160015Z  
 
THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 590  
CONTINUES.  
 
SUMMARY...A WELL ORGANIZED BOWING CLUSTER SHOULD CONTINUE ACROSS  
SOUTHEASTERN IA INTO NORTHWESTERN IL THIS EVENING. DAMAGING GUSTS  
(SOME 70+ MPH) ARE LIKELY.  
 
DISCUSSION...AS OF 2245 UTC, REGIONAL RADAR IMAGERY SHOWS A STRONGER  
BOWING CLUSTER HAS EMERGED FROM THE INITIAL CONVECTION OF STORMS  
OVER EASTERN IA. DOWNSTREAM, A VERY UNSTABLE ENVIRONMENT (4000-5000  
J/KG OF SBCAPE) REMAINS IN PLACE. WHILE VERTICAL SHEAR (25-35 KT) IS  
EXPECTED TO DECREASE WITH SOUTHERN EXTENT, EVIDENCE OF AN ELEVATED  
REAR-INFLOW JET AND A 20-25 DEG F COLD POOL, ALONG WITH THE DEGREE  
OF BUOYANCY SUGGEST MAINTENANCE OF THIS COMPLEX IS LIKELY FOR AT  
LEAST A FEW MORE HOURS. WITH SEVERAL GUSTS TO 70+ MPH OBSERVED OVER  
THE 60 MINUTES, DAMAGING WINDS REMAIN LIKELY ACROSS  
EASTERN/SOUTHEASTERN IA, INTO NORTHWESTERN AND POSSIBLE  
NORTH-CENTRAL IL THIS EVENING.  
 
CAM GUIDANCE HAS NOT HANDLED THE CONVECTIVE EVOLUTION PARTICULARITY  
WELL THUS FAR, WITH ONLY A FEW OUTLIER SOLUTIONS CAPTURING THE  
INTENSITY OF THE BOW. THIS LENDS LOWER CONFIDENCE TO THE DOWNSTREAM  
SEVERE RISK THIS EVENING. HOWEVER, THE CONTINUED FAVORABLE  
ENVIRONMENT AND WELL-ORGANIZED RADAR PRESENTATION OF THE SYSTEM DOES  
SUGGEST AT LEAST SOME DAMAGING WIND POTENTIAL MAY OCCUR DOWNSTREAM  
OF THE EASTERN EDGE OF WW590 IN IL TONIGHT. CONDITIONS WILL CONTINUE  
TO BE MONITORED SHOULD AN ADDITIONAL WATCH BE NEEDED LATER THIS  
EVENING.  
 
..LYONS.. 08/15/2025  
   
..PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT
 
 
ATTN...WFO...LOT...ILX...MKX...DVN...ARX...DMX...  
 
LAT...LON 42319219 42829123 42689053 42428952 42228929 41438913  
40788942 40379060 40859212 41289261 41679301 41939305  
42319219  
 
MOST PROBABLE PEAK TORNADO INTENSITY...UP TO 95 MPH  
MOST PROBABLE PEAK WIND GUST...65-80 MPH  
MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN  
 
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