152  
ACUS03 KWNS 210657  
SWODY3  
SPC AC 210656  
 
DAY 3 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK  
0156 AM CDT SUN JUL 21 2024  
 
VALID 231200Z - 241200Z  
   
..NO SEVERE THUNDERSTORM AREAS FORECAST
 
 
   
..SUMMARY
 
 
SEVERE-THUNDERSTORM POTENTIAL APPEARS LOW ON TUESDAY.  
   
..MID-ATLANTIC VICINITY
 
 
SOME MODEST DEEPENING OF THE UPPER TROUGH OVER THE GREAT LAKES IS  
EXPECTED ON TUESDAY. THIS MAY ALLOW FOR SOME ENHANCEMENT OF  
SOUTHWESTERLY MID/UPPER FLOW FROM THE CENTRAL APPALACHIANS INTO THE  
NORTHEAST. MEANWHILE, FORECAST GUIDANCE INDICATES SEVERAL SHORTWAVE  
VORTICITY MAXIMA MIGRATING THROUGH BROADER SOUTHWESTERLY FLOW FROM  
THE MID-SOUTH TO THE MID-ATLANTIC/SOUTHERN NEW ENGLAND. AT THE  
SURFACE, A WEAK LOW IS FORECAST TO MIGRATE ACROSS THE CHESAPEAKE BAY  
OR SOUTHERN NEW ENGLAND VICINITY. THE ACCOMPANYING SURFACE TROUGH  
MAY EXTEND GENERALLY ALONG THE I-95 CORRIDOR FROM SOUTHERN NY INTO  
EASTERN VA, AND COULD BECOME A FOCUS FOR THUNDERSTORM DEVELOPMENT  
DURING THE AFTERNOON AND EVENING. SOME FORECAST SOUNDINGS SUGGEST  
30-40 KT EFFECTIVE SHEAR MAGNITUDES AND AT LEAST WEAK INSTABILITY  
COULD SUPPORT SPORADIC DAMAGING GUSTS IN A VERY MOIST ENVIRONMENT.  
HOWEVER, FORECAST GUIDANCE VARIES ON THE PLACEMENT OF SURFACE  
FEATURES, AS WELL AS DEGREE OF INSTABILITY ACROSS THE REGION  
(INFLUENCED BY CLOUD COVER AND ANY ONGOING MORNING CONVECTION), AS  
WELL AS CONVECTIVE COVERAGE. LOW-END SEVERE PROBABILITIES MAY BE  
NEEDED IN SUBSEQUENT OUTLOOKS, BUT UNCERTAINTY IS TOO HIGH TO  
INCLUDE A CATEGORICAL SEVERE RISK AT THIS TIME.  
   
..UPPER MIDWEST VICINITY
 
 
A SURFACE COLD FRONT WILL SAG SOUTHWARD ACROSS SOUTHERN MN/WI ON  
TUESDAY. MODEST MOISTURE AND INSTABILITY WILL BE PLACE AHEAD OF THE  
FRONT ACROSS PORTIONS OF THE MID-MO/MS VALLEYS. THIS SHOULD SUPPORT  
SCATTERED THUNDERSTORMS DURING THE AFTERNOON/EVENING, THOUGH  
VERTICAL SHEAR IS FORECAST TO REMAIN VERY WEAK. THIS SHOULD LIMIT  
ORGANIZED SEVERE POTENTIAL, THOUGH ISOLATED GUSTY WINDS MAY  
ACCOMPANY ANY STRONGER CELLS.  
 
..LEITMAN.. 07/21/2024  
 

 
 
CLICK HERE TO GO TO PREVIOUS BULLETINS.

The Nexlab SPC Page Main Text Page