649  
ACUS01 KWNS 010448  
SWODY1  
SPC AC 010446  
 
DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK  
1146 PM CDT TUE SEP 30 2025  
 
VALID 011200Z - 021200Z  
   
..NO SEVERE THUNDERSTORM AREAS FORECAST  
 
   
..SUMMARY  
 
SEVERE THUNDERSTORMS ARE NOT EXPECTED TODAY THROUGH EARLY WEDNESDAY  
MORNING.  
   
..SYNOPSIS  
 
SOUTHWESTERLY MID/UPPER FLOW WILL PERSIST ACROSS THE PACIFIC  
NORTHWEST AS AN UPPER TROUGH REMAINS JUST OFFSHORE THROUGH THE  
PERIOD. LARGE-SCALE ASCENT AND COOLING ALOFT MAY SUPPORT ISOLATED  
THUNDERSTORMS OFFSHORE AND NEAR THE WA COAST/OLYMPIC PENINSULA.  
 
FURTHER EAST, A LEAD UPPER SHORTWAVE TROUGH WILL LIFT NORTHEAST  
ACROSS THE NORTHERN PLAINS. A SURFACE TROUGH/WIND SHIFT WILL DEVELOP  
EASTWARD ACROSS THE NORTHERN/CENTRAL PLAINS AS THIS OCCURS.  
SOUTHERLY LOW-LEVEL FLOW WILL MAINTAIN MODEST BOUNDARY LAYER  
MOISTURE AHEAD OF THE SURFACE BOUNDARY. CAPPING WILL LIKELY PRECLUDE  
SURFACE-BASED CONVECTION, BUT ISOLATED ELEVATED THUNDERSTORMS ARE  
POSSIBLE ACROSS EASTERN PORTIONS OF THE PLAINS TOWARD THE UPPER  
MIDWEST AMID WEAK INSTABILITY AND MODESTLY STEEP MIDLEVEL LAPSE  
RATES WITHIN THE WARM ADVECTION REGIME.  
 
ISOLATED SHOWERS AND THUNDERSTORMS MAY ALSO OCCUR ACROSS PORTIONS OF  
THE FL PENINSULA. HOWEVER, THUNDERSTORM COVERAGE/INTENSITY MAY BE  
LIMITED BY MIDLEVEL SUBSIDENCE DESPITE A SEASONALLY MOIST/UNSTABLE  
AIRMASS.  
 
..LEITMAN.. 10/01/2025  
 
 
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