336  
WWUS20 KWNS 182145  
SEL0  
SPC WW 182145  
SDZ000-190300-  
 
URGENT - IMMEDIATE BROADCAST REQUESTED  
SEVERE THUNDERSTORM WATCH NUMBER 600  
NWS STORM PREDICTION CENTER NORMAN OK  
345 PM MDT MON AUG 18 2025  
 
THE NWS STORM PREDICTION CENTER HAS ISSUED A  
 
* SEVERE THUNDERSTORM WATCH FOR PORTIONS OF  
WESTERN INTO CENTRAL SOUTH DAKOTA  
 
* EFFECTIVE THIS MONDAY AFTERNOON AND EVENING FROM 345 PM UNTIL  
900 PM MDT.  
 
* PRIMARY THREATS INCLUDE...  
SCATTERED LARGE HAIL AND ISOLATED VERY LARGE HAIL EVENTS TO 3  
INCHES IN DIAMETER POSSIBLE  
ISOLATED DAMAGING WIND GUSTS TO 70 MPH POSSIBLE  
 
SUMMARY...ISOLATED SUPERCELLS WILL LIKELY CONTINUE TO POSE A RISK  
FOR LARGE TO VERY LARGE HAIL (1 TO 3 INCHES IN DIAMETER) THROUGH THE  
LATE AFTERNOON AND EARLY EVENING. A CLUSTER OF THUNDERSTORMS MAY  
EVENTUALLY EVOLVE AND GRADUALLY MOVE EAST-SOUTHEAST INTO CENTRAL  
SOUTH DAKOTA THIS EVENING. THE PRIMARY THREATS WITH THE POTENTIAL  
THUNDERSTORM CLUSTER WILL BE LARGE HAIL AND SEVERE GUSTS (60-70  
MPH).  
 
THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 85  
STATUTE MILES NORTH AND SOUTH OF A LINE FROM 35 MILES NORTH  
NORTHWEST OF RAPID CITY SD TO 30 MILES EAST NORTHEAST OF PIERRE SD.  
FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH  
OUTLINE UPDATE (WOUS64 KWNS WOU0).  
 
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 599...  
 
AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT TO  
3 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60 KNOTS. A  
FEW CUMULONIMBI WITH MAXIMUM TOPS TO 450. MEAN STORM MOTION VECTOR  
29015.  
 
...SMITH  
 
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