109  
ACUS01 KWNS 221632  
SWODY1  
SPC AC 221630  
 
DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK  
1130 AM CDT FRI OCT 22 2021  
 
VALID 221630Z - 231200Z  
 
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON  
ACROSS EASTERN NC/SOUTHEASTERN VA...AND LATE TONIGHT ALONG THE  
SOUTHEASTERN KS/NORTHEASTERN OK BORDER...  
   
..SUMMARY
 
 
THUNDERSTORMS CAPABLE OF PRODUCING ISOLATED WIND DAMAGE, MARGINALLY  
SEVERE HAIL, AND A BRIEF TORNADO ARE POSSIBLE ACROSS EASTERN NORTH  
CAROLINA AND FAR SOUTHEAST VIRGINIA TODAY. HAIL MAY ALSO OCCUR  
ACROSS PARTS OF SOUTHEASTERN KANSAS AND NORTHEASTERN OKLAHOMA LATE  
TONIGHT.  
   
..EASTERN NC/SOUTHEASTERN VA THIS AFTERNOON
 
 
A COUPLE OF COLD FRONT SEGMENTS (ONE ACROSS NORTHERN NC AND ANOTHER  
ACROSS CENTRAL CHESAPEAKE BAY) WILL CONTINUE TO SAG SOUTHEASTWARD  
THROUGH THE AFTERNOON, AS EMBEDDED SPEED MAXIMA ROTATE EASTWARD  
THROUGH THE BASE OF A DEEP CLOSED LOW OVER JAMES BAY. SURFACE  
TEMPERATURES WARMING INTO THE 75-80 F RANGE AND BOUNDARY-LAYER  
DEWPOINTS IN THE MID 60S WILL CONTRIBUTE TO MLCAPE OF 1000-1500 J/KG  
ACROSS EASTERN NC AND EXTREME SOUTHEASTERN VA THIS AFTERNOON.  
SCATTERED THUNDERSTORM DEVELOPMENT IS EXPECTED BY EARLY-MID  
AFTERNOON (18-20Z) ALONG THE FRONTAL SEGMENTS AND DIFFERENTIAL  
HEATING ZONE NEAR THE SOUTHEASTERN VA/NC BORDER, AND STORMS WILL  
SUBSEQUENTLY SPREAD EAST-NORTHEASTWARD. THE MODERATE BUOYANCY WILL  
COMBINE WITH EFFECTIVE BULK SHEAR OF 35-40 KT AND EFFECTIVE SRH OF  
100-150 M2/S2 TO SUPPORT ISOLATED SUPERCELLS WITH AN ATTENDANT  
THREAT FOR ISOLATED WIND DAMAGE, AS WELL AS ISOLATED HAIL NEAR 1"  
DIAMETER, AND PERHAPS A BRIEF/WEAK TORNADO.  
   
..SOUTHEASTERN KS/NORTHEASTERN OK BORDER REGION EARLY SATURDAY
 
 
LOW-LEVEL MOISTURE WILL CONTINUE TO INCREASE FROM SOUTH-TO-NORTH  
FROM TX INTO OK, IN RESPONSE TO WEAK LEE CYCLOGENESIS ACROSS THE  
SOUTHERN/CENTRAL HIGH PLAINS. ELEVATED CONVECTION THIS MORNING  
ACROSS NORTHWEST AND CENTRAL OK IS EVIDENCE OF THIS MOISTURE  
INCREASE ABOVE THE SURFACE, AND AN INCREASE IN ELEVATED STORMS IS  
EXPECTED OVERNIGHT IN CONJUNCTION WITH STRENGTHENING WARM ADVECTION  
AND A SOUTHWESTERLY LOW-LEVEL JET OF 35-40 KT. MUCAPE OF 1000-1500  
J/KG, MIDLEVEL LAPSE RATES NEAR 7 C/KM, AND EFFECTIVE BULK SHEAR OF  
35-40 KT WILL SUPPORT SOME POTENTIAL FOR AT LEAST TRANSIENT  
SUPERCELL STRUCTURES CAPABLE OF PRODUCING ISOLATED HAIL NEAR 1"  
DIAMETER.  
 
..THOMPSON.. 10/22/2021  
 

 
 
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