913  
ACUS01 KWNS 230101  
SWODY1  
SPC AC 230100  
 
DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK  
0800 PM CDT TUE AUG 22 2017  
 
VALID 230100Z - 231200Z  
 
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS EASTERN  
PA...NORTHERN NJ...SOUTHEAST NY INTO NEW ENGLAND...  
 
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS SURROUNDING THE  
NORTHEAST U.S. SLIGHT RISK AREA...  
 
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM PARTS OF  
MIDDLE AND EASTERN TN INTO NORTHERN AL...  
 
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PART OF THE  
SOUTHERN PLAINS...  
   
..SUMMARY
 
 
SCATTERED STRONG TO SEVERE STORMS REMAIN A THREAT ACROSS EASTERN  
PENNSYLVANIA INTO PARTS OF NEW ENGLAND THIS EVENING AND PERHAPS TO  
THE EARLY OVERNIGHT.  
   
..NORTHEAST STATES
 
 
ALTHOUGH INSTABILITY WILL BE WEAKENING, GIVEN LOSS OF DAYTIME  
HEATING, STORMS WILL CONTINUE TO SPREAD ACROSS EASTERN PA INTO  
NORTHERN NJ AND SOUTHEAST NY TO PARTS OF NEW ENGLAND THIS EVENING TO  
THE EARLY OVERNIGHT, AS STRONG FORCING FOR ASCENT SHOULD COMPENSATE  
FOR THE WEAKER INSTABILITY IN THE SHORT TERM. STRONGLY SHEARED  
ENVIRONMENT, AS DEEP-LAYER WINDS STRENGTHEN INTO NEW ENGLAND, WILL  
CONTINUE TO FAVOR STORM ORGANIZATION WITH LOW-LEVEL ROTATION  
REMAINING POSSIBLE FOR A TORNADO OR TWO.  
   
..PORTIONS OF MIDDLE AND EASTERN TN AND NORTHERN AL
 
 
A BAND OF STORMS WILL CONTINUE TO ADVANCE TO THE SOUTH-SOUTHEAST  
THROUGH MIDDLE INTO PARTS OF EASTERN TN, AND PERHAPS NORTHERN AL YET  
THIS EVENING. ALTHOUGH INSTABILITY WILL UNDERGO FURTHER WEAKENING,  
GIVEN THE LOSS OF DAYTIME HEATING, FORCING FOR ASCENT ATTENDANT TO  
THE SOUTHERN EXTENT OF THE GREAT LAKES/OH VALLEY MAY COMPENSATE  
ALLOWING FOR AN ADDITIONAL STRONG TO SEVERE STORM. WEAK EFFECTIVE  
BULK SHEAR WILL PRECLUDE STORM ORGANIZATION, THOUGH WATER-LOADED  
DOWNDRAFTS PER PRECIPITABLE WATER RANGING FROM 1.5-2.0 INCHES AND  
COLD POOL DEVELOPMENT COULD LOCALLY ENHANCE THE THREAT FOR  
STRONGER/DAMAGING WIND GUSTS. THIS THREAT SHOULD WANE BY LATE  
EVENING, AS SURFACE-BASED INHIBITION WILL BECOME TOO STRONG TO  
OVERCOME FOR STRONGER MOMENTUM AIR TO REACH THE GROUND.  
   
..SOUTHERN PLAINS
 
 
STORM MERGERS ACROSS NORTHWEST/WEST-CENTRAL TX AND ACROSS OK WILL  
CONTINUE TO POSE A THREAT FOR LOCALLY STRONG/DAMAGING WIND GUSTS,  
GIVEN RESIDUAL MODERATE INSTABILITY, HIGH PRECIPITABLE WATER OF  
1.5-2.0 INCHES, AND SOME COLD POOL DEVELOPMENT ENHANCING THIS  
ISOLATED SEVERE THREAT THIS EVENING.  
 
..PETERS.. 08/23/2017  
 

 
 
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