647  
FXUS01 KWBC 220521  
PMDSPD  
 
SHORT RANGE FORECAST DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
119 AM EDT SAT AUG 22 2026  
 
VALID 12Z SAT AUG 22 2026 - 12Z MON AUG 24 2026  
 
...FLASH FLOODING AND SEVERE WEATHER THREAT ACROSS PORTIONS OF  
EASTERN U.S. ON SATURDAY...  
 
...FLASH FLOODING AND SEVERE WEATHER THREAT ACROSS PORTIONS OF  
ROCKIES/PLAINS INTO THE SOUTHWEST THROUGH THE WEEKEND...  
 
...DANGEROUS HEAT CONTINUES ACROSS SOUTH-CENTRAL U.S. INTO THE  
SOUTHWEST THROUGH THE WEEKEND...  
 
A AMPLIFIED PATTERN WITH A DEEPENING TROUGH OVER EASTERN U.S. AND  
PERSISTENT RIDGING OVER THE SOUTHERN PLAINS/SOUTHWEST WILL BRING  
UNSETTLED CONDITIONS ACROSS THE ROCKIES/PLAINS INTO EASTERN U.S.  
INTO EARLY NEXT WEEK. AT THE SURFACE, THE LOW OVER THE GREAT  
LAKES/OHIO VALLEY WILL CONTINUE TO STRENGTHEN, WHILE FRONTAL  
BOUNDARIES BEGIN TO MERGE. THE SLOW MOVING BOUNDARY WILL DRAPE  
ACROSS THE OHIO VALLEY/MID-ATLANTIC, INTO THE SOUTHEAST AND  
SOUTHERN PLAINS BY SATURDAY. INCREASING CYCLONIC FLOW, UPPER-LEVEL  
FORCING, AND SUFFICIENT MOISTURE WILL MAINTAIN MULTIPLE ROUNDS OF  
SHOWERS AND THUNDERSTORMS ALONG THE BOUNDARY, WITH LOCALLY HEAVY  
RAINFALL POSSIBLE ACROSS PORTIONS OF THE GREAT LAKES,  
MID-ATLANTIC/CAROLINAS INTO THE NORTHEAST. BY SUNDAY, THE SYSTEM  
WILL CONTINUE TO MOVE EASTWARD, WITH CYCLOGENESIS NORTH OF THE  
GREAT LAKES, SUPPORTING ADDITIONAL SHOWERS FOR PORTIONS OF THE  
NORTHEAST. ADDITIONALLY, STORM PREDICTION CENTER HIGHLIGHTS A  
SEVERE THUNDERSTORM THREAT CAPABLE OF PRODUCING SEVERE HAIL AND  
WIND ACROSS PORTIONS OF SOUTHERN PLAINS AND OHIO VALLEY/GREAT  
LAKES/MID-ATLANTIC FOR SATURDAY, WHILE THE THREAT IS CONFINED TO  
THE NORTHEAST BY SUNDAY.  
 
FURTHER WEST, THE STATIONARY FRONTAL BOUNDARY WILL CONTINUE TO  
STRETCH ACROSS THE ROCKIES/PLAINS INTO THE FOUR CORNERS. THE  
COMBINATION OF THE SHORTWAVE DISTURBANCES, SLOW MOVING FRONTAL  
BOUNDARY, AND MOISTURE INFLUX CAN LEAD TO SHOWERS AND  
THUNDERSTORMS. THESE SYSTEMS MAY BE CAPABLE OF PRODUCING EXCESSIVE  
RAINFALL/FLASH FLOODING, LIGHTNING, SEVERE HAIL AND DAMAGING WINDS  
ACROSS PORTIONS OF THE ROCKIES/PLAINS INTO THE SOUTHWEST THROUGH  
THE WEEKEND.  
 
THE SOUTHERN TIER WILL REMAIN DOMINATED BY THE UPPER-LEVEL RIDGING  
CENTERED OVER THE SOUTHWEST. THIS WILL MAINTAIN ABOVE NORMAL  
TEMPERATURES INTO NEXT WEEK. THE DANGEROUS HEAT WILL BUILD ACROSS  
SOUTH-CENTRAL U.S. AND SOUTHWEST WITH DAYTIME HIGHS OF 100-110  
DEGREES ACROSS THE SOUTHERN PLAINS INTO THE SOUTHWEST, WITH  
NUMEROUS RECORD BREAKING HIGHS. 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  
 

 
 
CLICK HERE TO GO TO PREVIOUS BULLETINS.

The Nexlab HPC Page Main Text Page