176  
ACUS01 KWNS 041233  
SWODY1  
SPC AC 041231  
 
DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK  
0731 AM CDT THU SEP 04 2025  
 
VALID 041300Z - 051200Z  
 
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS IN PARTS OF THE  
EAST AND THE MIDDLE MISSOURI VALLEY...  
   
..SUMMARY  
 
ISOLATED DAMAGING WINDS ARE POSSIBLE ACROSS PARTS OF THE NORTHEAST  
TO THE SOUTHERN APPALACHIANS AND TENNESSEE VALLEY FROM LATE MORNING  
THROUGH THE AFTERNOON. ISOLATED SEVERE GUSTS ARE POSSIBLE ACROSS  
PARTS OF THE MIDDLE MISSOURI VALLEY LATE THIS AFTERNOON INTO THE  
EARLY EVENING.  
   
..SOUTHERN APPALACHIANS/TN VALLEY TO THE NORTHEAST  
 
ISOLATED TO SCATTERED SHOWERS/THUNDERSTORMS ARE ONGOING THIS MORNING  
FROM THE LOWER GREAT LAKES SOUTHWARD INTO THE SOUTHERN APPALACHIANS.  
WATER-VAPOR IMAGERY SHOWS A VERTICALLY STACKED CYCLONE OVER ONTARIO  
WITH A DISTURBANCE ROTATING THROUGH THE BASAL PORTION OF THE LARGER  
SCALE TROUGH. THIS MID-LEVEL FEATURE WILL QUICKLY MOVE FROM THE  
UPPER OH VALLEY INTO THE NY/CENTRAL APPALACHIANS BY THE LATE  
AFTERNOON.  
 
DESPITE WEAK MID-LEVEL LAPSE RATES, SOME DIURNAL HEATING AHEAD OF  
THIS ACTIVITY SHOULD YIELD GRADUAL INTENSIFICATION OF THUNDERSTORMS  
AND INCREASED STORM COVERAGE BY LATE MORNING ACROSS PARTS OF THE  
SOUTHERN APPALACHIANS. LOCALLY DAMAGING WINDS AND MARGINALLY SEVERE  
HAIL ARE POSSIBLE, CENTERED ON THE EASTERN TN VICINITY.  
 
ISOLATED TO SCATTERED MULTICELL CLUSTERS AND SHORT-LINE SEGMENTS MAY  
ALSO EVOLVE IN THE AFTERNOON FROM CONVECTION ALONG/AHEAD OF THE COLD  
FRONT AND LEE TROUGH. WEAK MLCAPE AND POOR MID-LEVEL LAPSE RATES  
WILL TEMPER CONVECTIVE VIGOR, WITH DAMAGING WIND POTENTIAL LOCALLY  
AUGMENTED TO WHERE POCKETS OF DEEPER BOUNDARY-LAYER HEATING OCCUR.  
   
..MID-MO VALLEY  
 
AN INTENSE MID-LEVEL SPEED MAX/SHORTWAVE TROUGH WILL QUICKLY MOVE  
FROM THE SOUTHERN PART OF THE PRAIRIE PROVINCES INTO THE MID MO  
VALLEY BY THIS AFTERNOON, BEFORE MOVING INTO THE SOUTHWEST GREAT  
LAKES BY EARLY FRIDAY MORNING. SOME MODEL SPREAD EXISTS ON THE  
MAGNITUDE OF DESTABILIZATION IMMEDIATELY AHEAD OF A COLD FRONT  
FORECAST TO SWEEP THROUGH THE REGION LATE THIS AFTERNOON INTO THE  
EVENING. HOWEVER, WEAK BUOYANCY APPEARS LIKELY TO DEVELOP AND  
LOW-LEVEL LAPSE RATES MAY BECOME ADEQUATELY STEEP TO SUPPORT A  
NARROW CORRIDOR OF LOW-TOPPED STORMS CAPABLE OF ISOLATED SEVERE  
GUSTS.  
   
..KS  
 
AN ACCELERATING AND SHARPENING COLD FRONT WILL SWEEP SOUTH ACROSS  
THE CENTRAL HIGH/GREAT PLAINS TONIGHT. UNDERCUT/ELEVATED CONVECTION  
SHOULD FORM TO THE COLD SIDE OF THIS BOUNDARY EARLY FRIDAY MORNING.  
LOCALLY STRONG SURFACE GUSTS MAY ACCOMPANY THIS ACTIVITY AMID ROBUST  
LOW-LEVEL NORTHERLIES.  
 
..SMITH/BENTLEY.. 09/04/2025  
 
 
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