645  
ACUS03 KWNS 021928  
SWODY3  
SPC AC 021928  
 
DAY 3 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK  
0228 PM CDT TUE SEP 02 2025  
 
VALID 041200Z - 051200Z  
 
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS THURSDAY IN A  
CORRIDOR FROM THE LEE OF THE ALLEGHENY MOUNTAINS INTO THE TENNESSEE  
VALLEY...  
   
..SUMMARY  
 
SCATTERED STRONG THUNDERSTORMS MAY IMPACT A CORRIDOR FROM THE LEE OF  
THE ALLEGHENY MOUNTAINS INTO THE TENNESSEE VALLEY ON THURSDAY,  
ACCOMPANIED BY A RISK FOR POTENTIALLY DAMAGING WIND GUSTS.  
   
..DISCUSSION  
 
MODELS SUGGEST THAT AMPLIFIED LARGE-SCALE MID-LEVEL TROUGHING TO THE  
EAST OF THE CANADIAN/U.S. ROCKIES MAY CONTINUE TO GRADUALLY  
CONSOLIDATE DURING THIS PERIOD, BECOMING CENTERED AROUND A NOTABLE  
DEEPENING AND OCCLUDING CYCLONE ACROSS NORTHERN ONTARIO, TO THE WEST  
OF JAMES BAY. AROUND THE SOUTHWESTERN PERIPHERY OF THIS FEATURE, A  
SIGNIFICANT TRAILING SHORT WAVE PERTURBATION IS FORECAST TO DIG  
ACROSS THE NORTHERN U.S. GREAT PLAINS AND MIDWEST THROUGH LOWER  
GREAT LAKES REGION, ACCOMPANIED BY A SECONDARY SURFACE CYCLONE AND  
REINFORCING COLD INTRUSION FROM THE LEE OF THE NORTHERN ROCKIES  
THROUGH MUCH OF THE CENTRAL GREAT PLAINS AND LOWER MISSOURI VALLEY  
BY DAYBREAK FRIDAY. IT APPEARS THAT THE OCCLUDING PRECEDING FRONT  
WILL PROGRESS EAST/SOUTHEAST OF THE LOWER GREAT LAKES AND OHIO  
VALLEY, BEFORE STALLING AND WEAKENING, WHILE SEASONABLY HIGH  
MOISTURE CONTENT REMAINS CONFINED TO A REMNANT PRECEDING BOUNDARY  
ACROSS THE SOUTHWESTERN ATLANTIC INTO SOUTHERN FLORIDA/SOUTHEASTERN  
GULF BASIN.  
   
..NORTHERN MID ATLANTIC INTO TENNESSEE VALLEY  
 
AIDED BY MODESTLY STEEPENING LOWER TROPOSPHERIC LAPSE RATES, IT  
APPEARS THAT RESIDUAL BOUNDARY-LAYER MOISTURE MAY BECOME SUPPORTIVE  
OF WEAK TO MODEST DESTABILIZATION, WITHIN AT LEAST A NARROW  
PRE-FRONTAL CORRIDOR ACROSS THE REGION DURING THE DAY THURSDAY.  
THIS MAY INCLUDE CAPE ON THE ORDER OF 500-1000 J/KG, IN THE PRESENCE  
OF STRENGTHENING, BUT STILL MODEST, CYCLONIC WEST-SOUTHWESTERLY  
LOWER/MID-TROPOSPHERIC FLOW, INCLUDING 20-40+ KT IN THE 850-500 MB  
LAYER. IT IS POSSIBLE THAT THIS ENVIRONMENT MAY BECOME CONDUCIVE TO  
AT LEAST WIDELY SCATTERED STRONG THUNDERSTORM DEVELOPMENT CAPABLE OF  
PRODUCING A FEW STRONG TO POTENTIALLY DAMAGING WIND GUSTS.  
 
..KERR.. 09/02/2025  
 
 
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