051  
ACUS03 KWNS 220711  
SWODY3  
SPC AC 220710  
 
DAY 3 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK  
0210 AM CDT SUN OCT 22 2017  
 
VALID 241200Z - 251200Z  
 
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS TUESDAY  
AFTERNOON AND EVENING ACROSS PARTS OF THE NORTHERN MID ATLANTIC  
COAST REGION INTO WESTERN PORTIONS OF NEW ENGLAND...  
   
..SUMMARY
 
 
THUNDERSTORMS MAY IMPACT PARTS OF THE NORTHEAST ON TUESDAY,  
ACCOMPANIED BY AT LEAST SOME RISK FOR POTENTIALLY DAMAGING WIND  
GUSTS.  
   
..SYNOPSIS
 
 
WHILE ANOTHER SHORT WAVE TROUGH PROGRESSES INLAND ACROSS THE  
CANADIAN ROCKIES, AROUND THE CREST OF BROAD UPPER RIDGING EXTENDING  
ACROSS THE EASTERN PACIFIC THROUGH MUCH OF WESTERN NORTH AMERICA,  
MODELS INDICATE THAT LARGE-SCALE TROUGHING EAST OF MISSISSIPPI  
VALLEY MAY AMPLIFY FURTHER THROUGH THIS PERIOD. ENCOMPASSING MUCH  
OF THE EASTERN U.S., THIS TROUGHING MAY TAKE ON MORE OF A NEGATIVE  
TILT AS IT APPROACHES THE ATLANTIC SEABOARD TUESDAY THROUGH TUESDAY  
NIGHT. AN ASSOCIATED SURFACE COLD FRONT IS STILL EXPECTED TO  
PRECEDE THE UPPER TROUGH, WITH ONE SHALLOWER PORTION SURGING ACROSS  
MUCH OF THE REMAINDER OF THE SOUTHEAST, INTO THE FLORIDA PENINSULA,  
BY EARLY TUESDAY AFTERNOON. FARTHER NORTH, THE FRONT MAY NOT  
ADVANCE INTO THE NORTHERN MID ATLANTIC COAST AND HUDSON/CHAMPLAIN  
VALLEYS UNTIL LATE TUESDAY AFTERNOON OR EVENING. OF PARTICULAR  
CONCERN TO SEVERE WEATHER POTENTIAL, IS THE POSSIBILITY OF RATHER  
STRONG LOWER/MID TROPOSPHERIC WIND FIELDS (UP TO 50-70+ KT IN THE  
850-500 MB LAYER) WITHIN A CORRIDOR AHEAD OF THE NORTHERN PORTION OF  
THE FRONT.  
   
..NORTHEAST
 
 
PROSPECTS FOR MORE THAN VERY WEAK BOUNDARY LAYER DESTABILIZATION  
APPEAR RATHER SLIM WITHIN THE PRE-FRONTAL CORRIDOR WITH STRONGEST  
MEAN LOWER/MID TROPOSPHERIC WINDS, FROM PORTIONS OF THE NORTHERN MID  
ATLANTIC COAST REGION INTO WESTERN NEW ENGLAND, DURING THE DAY  
TUESDAY INTO TUESDAY EVENING. AND RELATIVELY WARM MID/UPPER LEVELS  
MAY PRECLUDE, OR AT LEAST LIMIT, THE POTENTIAL FOR THERMODYNAMIC  
PROFILES TO SUPPORT LIGHTNING. HOWEVER, GIVEN THE POTENTIAL  
STRENGTH OF THE WIND FIELDS OFF THE SURFACE, THE DEVELOPMENT OF EVEN  
RELATIVELY WEAK/LOW-TOPPED CONVECTION MAY AID THE DOWNWARD TRANSFER  
OF HIGHER MOMENTUM, CONTRIBUTING TO THE POTENTIAL FOR AT LEAST  
LOCALIZED WIND DAMAGE.  
 
..KERR.. 10/22/2017  
 

 
 
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