870  
ACUS01 KWNS 301958  
SWODY1  
SPC AC 301957  
 
DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK  
0257 PM CDT TUE SEP 30 2025  
 
VALID 302000Z - 011200Z  
   
..NO SEVERE THUNDERSTORM AREAS FORECAST  
 
   
..SUMMARY  
 
SEVERE THUNDERSTORMS ARE UNLIKELY THROUGH TONIGHT.  
   
..20Z UPDATE  
 
ONLY MINOR CHANGES WERE MADE TO THE FORECAST WITH THIS UPDATE,  
INCLUDING A SLIGHT EXPANSION OF THE GENERAL THUNDERSTORM AREA IN THE  
APPALACHIANS. SEE THE PREVIOUS DISCUSSION BELOW FOR DETAILS.  
 
..WEINMAN.. 09/30/2025  
   
PREV DISCUSSION  
/ISSUED 1100 AM CDT TUE SEP 30 2025/  
   
..SYNOPSIS AND DISCUSSION  
 
UPPER RIDGING WILL BE MAINTAINED TODAY ACROSS THE MIDWEST AND GREAT  
LAKES, WHILE UPSTREAM TROUGHING ADVANCES INLAND OVER THE WESTERN  
STATES. MULTIPLE EMBEDDED MID-LEVEL SHORTWAVE TROUGHS WILL ENCOURAGE  
THUNDERSTORM DEVELOPMENT THROUGH THE PERIOD FROM PARTS OF THE GREAT  
BASIN INTO THE NORTHERN/CENTRAL ROCKIES AND ADJACENT HIGH PLAINS.  
THUNDERSTORMS MAY ALSO OCCUR ACROSS PARTS OF COASTAL WA WITH  
LOW-TOPPED CONVECTION IN CLOSE PROXIMITY TO AN UPPER LOW OFF THE  
COAST OF BRITISH COLUMBIA. OTHER ISOLATED THUNDERSTORMS APPEAR  
POSSIBLE THIS AFTERNOON OVER PORTIONS OF THE SOUTHERN APPALACHIANS  
AND FL ATLANTIC COAST. FOR ALL THESE AREAS, WEAK INSTABILITY AND/OR  
MODEST SHEAR SHOULD PRECLUDE ORGANIZED SEVERE THUNDERSTORMS.  
 
 
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