488  
ACUS48 KWNS 290758  
SWOD48  
SPC AC 290757  
 
DAY 4-8 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK  
0257 AM CDT THU JUL 29 2021  
 
VALID 011200Z - 061200Z  
   
..DISCUSSION
 
   
..SUNDAY/DAY 4 TO TUESDAY/DAY 6
 
 
A BROAD CYCLONIC FLOW PATTERN IS FORECAST ACROSS THE NORTHERN AND  
EASTERN U.S. FROM LATE THIS WEEKEND INTO EARLY NEXT WEEK. A MOIST  
AIRMASS SHOULD BE LOCATED FROM THE GULF COAST STATES INTO THE MID  
MISSISSIPPI VALLEY. A COLD FRONT IS FORECAST TO MOVE SOUTHWARD FROM  
THE OZARKS AND OHIO VALLEY ON SUNDAY SOUTHWARD INTO THE GULF COAST  
STATES BY TUESDAY. THUNDERSTORM DEVELOPMENT WILL BE POSSIBLE IN THE  
VICINITY OF THE FRONT EACH AFTERNOON AND EVENING. ALTHOUGH MODERATE  
INSTABILITY IS EXPECTED TO DEVELOP NEAR AND TO THE SOUTH OF THE  
FRONT EACH DAY, ANY SEVERE THREAT SHOULD REMAIN RELATIVELY ISOLATED  
DUE TO DEEP-LAYER SHEAR ON THE WEAK SIDE. MARGINALLY SEVERE WINDS  
WOULD BE THE GREATEST THREAT DUE TO THE WARM TEMPERATURES ALOFT.  
   
..WEDNESDAY/DAY 7 AND THURSDAY/DAY 8
 
 
ON WEDNESDAY AND THURSDAY, AN UPPER-LEVEL LOW IS FORECAST TO DEVELOP  
ACROSS THE EASTERN GREAT LAKES REGION. FURTHER TO THE WEST ACROSS  
THE NORTH-CENTRAL STATES, UPPER-LEVEL FLOW IS FORECAST TO BECOME  
MORE WESTERLY. THE PATTERN SHOULD RESULT IN MOISTURE ADVECTION IN  
THE CENTRAL U.S. WHERE POCKETS OF MODERATE INSTABILITY COULD DEVELOP  
DURING THE AFTERNOON. THUNDERSTORMS THAT FORM IN PROXIMITY TO THESE  
POCKETS OF INSTABILITY COULD DEVELOP AN ISOLATED SEVERE THREAT. BUT  
THE MESOSCALE DETAILS ON WEDNESDAY AND THURSDAY ARE UNPREDICTABLE AT  
THIS EXTENDED RANGE. FOR THIS REASON, A SEVERE THREAT AREA CAN NOT  
BE ADDED AT THIS TIME.  
 
..BROYLES.. 07/29/2021  
 
CLICK HERE TO GO TO PREVIOUS BULLETINS.

The Nexlab SPC Page Main Text Page