676  
FXUS01 KWBC 210638  
PMDSPD  
 
SHORT RANGE FORECAST DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
233 AM EDT FRI AUG 21 2026  
 
VALID 12Z FRI AUG 21 2026 - 12Z SUN AUG 23 2026  
 
...SEVERE WEATHER AND FLASH FLOOD THREATS ACROSS PARTS OF THE EAST  
THROUGH SATURDAY, WITH SEVERE/FLOODING THREATS ACROSS PORTIONS OF  
CENTRAL PLAINS ON FRIDAY...  
 
...DANGEROUS HEAT PERSISTS IN THE SOUTH WHILE BUILDING INTO THE  
SOUTHWEST THROUGH THE WEEKEND...  
 
UNSETTLED WEATHER CONTINUES INTO THE WEEKEND AS A BROAD  
UPPER-LEVEL RIDGE REMAINS ENTRENCHED ACROSS THE SOUTHERN U.S.,  
WHILE SEVERAL SHORTWAVE DISTURBANCES AND SURFACE BOUNDARIES MOVE  
THROUGH CENTRAL AND EASTERN U.S. THE FRONTAL BOUNDARY DRAPING  
ACROSS THE SOUTHERN PLAINS TO THE SOUTHEAST AND NORTHWARD INTO THE  
MID-ATLANTIC WILL CONTINUE TO INTERACT WITH UNSTABLE AND WARM  
AIRMASS. THIS WILL SUPPORT MULTIPLE ROUNDS OF SHOWERS AND  
THUNDERSTORMS, LEADING TO POSSIBLE SLIGHT RISK FOR EXCESSIVE  
RAINFALL AND FLASH FLOODING, ESPECIALLY ACROSS VIRGINIA INTO THE  
CAROLINAS. ADDITIONALLY, STORM PREDICTION CENTER HAS HIGHLIGHTED A  
SLIGHT RISK FOR SEVERE THUNDERSTORMS, CAPABLE OF PRODUCING  
SEVERE/DAMAGING WIND GUST ON FRIDAY ACROSS THE  
SOUTHEAST/CAROLINAS. THE BOUNDARY WILL CONTINUE TO LIFT NORTHWARD  
AND SLOWLY MOVE EASTWARD ON SATURDAY, WHILE A SECOND BOUNDARY  
FOLLOWS BEHIND. THIS WILL BRINGING ADDITIONAL RAINFALL ACROSS THE  
EASTERN SEABOARD, LEADING TO CLUSTERED THUNDERSTORMS THAT MAY  
PRODUCE EXCESSIVE RAINFALL/FLASH FLOODING, ESPECIALLY ACROSS THE  
EAST COAST, WHILE THE LOWER GREAT LAKES/OHIO VALLEY MAY EXPERIENCE  
SEVERE THUNDERSTORMS.  
 
ACROSS CENTRAL U.S., ANOTHER FRONTAL BOUNDARY WILL BRING CHANCES  
FOR SHOWERS AND THUNDERSTORMS AS THE BOUNDARY MOVES SOUTHWARD AND  
INTERACTS WITH INCREASING INSTABILITY AND DEEP-LAYER SHEAR.  
ORGANIZED CONVECTION MAY DEVELOP, WHICH MAY LEAD TO SLIGHT RISK  
FOR SEVERE THUNDERSTORMS, HAIL, AND DAMAGING WINDS ACROSS THE  
CENTRAL PLAINS AND MIDWEST, WHILE A MARGINAL RISK IS IN PLACE FOR  
EXCESSIVE RAINFALL/HEAVY RAINFALL ACROSS PORTIONS OF THE CENTRAL  
PLAINS, THAT MAY LEAD TO LOCALIZED FLOODING THROUGH SATURDAY  
MORNING. ACROSS THE SOUTHWEST, MONSOONAL MOISTURE WILL REMAIN  
CONCENTRATED ACROSS THE FOUR CORNERS AND SOUTHERN ROCKIES.  
AFTERNOON HEATING COMBINED WITH TERRAIN-DRIVEN CIRCULATIONS WILL  
INITIATE SCATTERED THUNDERSTORMS THROUGH THE WEEKEND, WITH LOCALLY  
HEAVY RAINFALL POSSIBLE FROM SLOW-MOVING STORMS. ON SATURDAY, THE  
RIDGE WILL SHIFT EASTWARD, WHILE A SHORTWAVE DISTURBANCE PUSHES  
INTO THE PACIFIC NORTHWEST. THE INFLUX OF MOISTURE WILL EXPAND THE  
FLOODING THREAT NORTHWARD, COVERING MUCH OF WESTERN U.S., AS  
STORMS ARE EXPECTED TO DEVELOP ALONG THE BOUNDARY. ADDITIONALLY,  
THE STORM MAY PRODUCE SEVERE THUNDERSTORMS AND A CHANCE FOR SMALL  
HAIL WITHIN THE STRONGER CELLS.  
 
MEANWHILE, DANGEROUS HEAT CONTINUES ACROSS THE SOUTH-CENTRAL U.S.  
AND THE SOUTHWEST THROUGH THE WEEKEND AS THE RIDGE CONTINUES TO  
SUPPORT ABOVE NORMAL TEMPERATURES. NUMEROUS DAILY RECORD HIGHS ARE  
EXPECTED, WITH DAYTIME HIGHS OF 100-110 DEGREES ACROSS THE  
SOUTHERN PLAINS INTO THE SOUTHWEST. WITH LITTLE TO NO OVERNIGHT  
RELIEF, AS MINIMUM TEMPERATURES WILL REMAIN WARM, AND HIGH  
HUMIDITY, HEAT INDICES MAY REACH 105-115 DEGREES. THEREFORE,  
EXPECT WIDESPREAD MAJOR TO EXTREME HEATRISK THROUGH THE WEEKEND.  
REFER TO KEY MESSAGES ISSUED BY WPC FOR ADDITIONAL INFORMATION ON  
THIS EVENT.  
 
OUDIT  
 
GRAPHICS AVAILABLE AT  
HTTPS://WWW.WPC.NCEP.NOAA.GOV/BASICWX/BASICWX_NDFD.PHP  
 
 
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