113  
ACUS01 KWNS 291621  
SWODY1  
SPC AC 291619  
 
DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK  
1119 AM CDT THU JUL 29 2021  
 
VALID 291630Z - 301200Z  
 
...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON  
AND EARLY EVENING OVER PARTS OF THE MID ATLANTIC REGION...  
   
..SUMMARY
 
 
DAMAGING THUNDERSTORM WINDS AND A TORNADO OR TWO WILL BE POSSIBLE  
TODAY OVER PARTS OF THE OHIO VALLEY, CENTRAL APPALACHIANS AND  
MID-ATLANTIC.  
   
..MID ATLANTIC
 
 
A CONVECTIVELY AIDED SHORTWAVE TROUGH, INCLUDING MULTIPLE MCVS, IS  
MOVING ACROSS THE UPPER OHIO VALLEY TODAY TOWARD THE MID-ATLANTIC  
REGION. ONE SUCH FEATURE IS CURRENTLY OVER NORTHEAST PA, WITH AN  
ASSOCIATED LINE OF THUNDERSTORMS MOVING QUICKLY TOWARD CENTRAL PA.  
WIDESPREAD CLOUDS WILL LIMIT HEATING AHEAD OF THIS LINE, SO IT MAY  
DELAY INTENSIFICATION UNTIL LATER TODAY. BUT BREAKS IN THE CLOUDS  
OVER THE EASTERN HALF OF PA AND MUCH OF NJ/DE/MD SUGGEST THAT THE  
LINE MAY BEGIN PRODUCING DAMAGING WIND GUSTS BY MID-AFTERNOON.  
THESE STORMS SHOULD MOVE OFFSHORE BY EARLY EVENING, ENDING THE  
SEVERE THREAT.  
   
..WV/VA
 
 
THE PRIMARY MCV FROM LAST NIGHT'S SEVERE ACTIVITY OVER THE GREAT  
LAKES REGION IS NOW OVER SOUTHEAST OH. THIS FEATURE WILL TRACK  
ACROSS WV INTO CENTRAL VA THIS AFTERNOON. IT IS UNCLEAR WHETHER THE  
MODELS HAVE A GOOD HANDLE ON THIS FORCING MECHANISM. THE POTENTIAL  
EXISTS FOR RE-DEVELOPMENT OF SEVERE THUNDERSTORMS NEAR THE MCV, SO  
HAVE EXPANDED THE SLGT/MRGL AREAS FARTHER SOUTH ACROSS WV/VA TO  
ACCOUNT FOR THIS POTENTIAL.  
   
..MO/IL AND OH VALLEY
 
 
AMPLE LOW-LEVEL MOISTURE AND CAPE RESIDE ACROSS THIS REGION, WITH  
DEWPOINTS IN THE LOW/MID 70S AND AREAS OF STRONG HEATING POTENTIAL.  
MOST 12Z CAM SOLUTIONS INDICATE SCATTERED THUNDERSTORM DEVELOPMENT  
ALONG AN AXIS FROM NORTHEAST MO EASTWARD INTO CENTRAL IN/OH. THIS  
ACTIVITY SHOULD BUILD SOUTHWARD INTO THE CAPE AXIS THROUGH EARLY  
EVENING. MULTICELL CLUSTERS CAPABLE OF DAMAGING WINDS AND HAIL  
APPEAR TO BE THE MAIN THREAT.  
   
..WY
 
 
NORTHEASTERLY/UPSLOPE LOW-LEVEL WINDS OVER EASTERN WY WILL MAINTAIN  
CONSIDERABLE MOISTURE OVER THE REGION, WHERE SCATTERED AFTERNOON  
THUNDERSTORMS ARE POSSIBLE. THIS MAY RESULT IN A FEW ISOLATED  
INTENSE STORMS CAPABLE OF HAIL OR GUSTY WINDS.  
 
..HART/KERR.. 07/29/2021  
 

 
 
CLICK HERE TO GO TO PREVIOUS BULLETINS.

The Nexlab SPC Page Main Text Page