588  
WWUS20 KWNS 161736  
SEL8  
SPC WW 161736  
ILZ000-INZ000-LMZ000-170100-  
 
URGENT - IMMEDIATE BROADCAST REQUESTED  
SEVERE THUNDERSTORM WATCH NUMBER 518  
NWS STORM PREDICTION CENTER NORMAN OK  
1235 PM CDT WED JUL 16 2025  
 
THE NWS STORM PREDICTION CENTER HAS ISSUED A  
 
* SEVERE THUNDERSTORM WATCH FOR PORTIONS OF  
NORTHERN ILLINOIS  
FAR NORTHWEST INDIANA  
LAKE MICHIGAN  
 
* EFFECTIVE THIS WEDNESDAY AFTERNOON AND EVENING FROM 1235 PM  
UNTIL 800 PM CDT.  
 
* PRIMARY THREATS INCLUDE...  
SCATTERED DAMAGING WIND GUSTS TO 70 MPH POSSIBLE  
ISOLATED LARGE HAIL EVENTS TO 1 INCH IN DIAMETER POSSIBLE  
A TORNADO OR TWO POSSIBLE  
 
SUMMARY...SCATTERED THUNDERSTORMS ARE FORECAST TO DEVELOP IN A  
NORTH-SOUTH BAND AND MOVE EAST ACROSS THE WATCH. A COUPLE OF THE  
STRONGER THUNDERSTORMS MAY ACQUIRE TRANSIENT SUPERCELL  
CHARACTERISTICS. SCATTERED DAMAGING GUSTS ARE THE PRIMARY HAZARD,  
BUT AN ISOLATED RISK FOR LARGE HAIL WILL ACCOMPANY THE STRONGER  
STORMS AND A TORNADO CANNOT BE RULED OUT.  
 
THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 75  
STATUTE MILES EAST AND WEST OF A LINE FROM 40 MILES EAST NORTHEAST  
OF ROCKFORD IL TO 20 MILES SOUTH SOUTHEAST OF MARSEILLES IL. FOR A  
COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE  
UPDATE (WOUS64 KWNS WOU8).  
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...  
 
REMEMBER...A SEVERE THUNDERSTORM WATCH MEANS CONDITIONS ARE  
FAVORABLE FOR SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH AREA.  
PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR THREATENING  
WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS AND POSSIBLE  
WARNINGS. SEVERE THUNDERSTORMS CAN AND OCCASIONALLY DO PRODUCE  
TORNADOES.  
 

 
 
OTHER WATCH INFORMATION...CONTINUE...WW 517...  
 
AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT TO  
1 INCH. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60 KNOTS. A FEW  
CUMULONIMBI WITH MAXIMUM TOPS TO 500. MEAN STORM MOTION VECTOR  
24025.  
 
...SMITH  
 
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