839  
FXUS01 KWBC 210801  
PMDSPD  
 
SHORT RANGE FORECAST DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
400 AM EDT TUE JUL 21 2026  
 
VALID 12Z TUE JUL 21 2026 - 12Z THU JUL 23 2026  
 
...STRONG FRONTAL SYSTEM TO PRODUCE WIDELY SCATTERED SEVERE  
WEATHER AND FLASH FLOODING FROM THE MID-SOUTH INTO THE NORTHEAST...  
   
..T.D. TWO TO BRING HEAVY RAIN THREATS ACROSS THE GULF COAST  
 
...MONSOONAL THUNDERSTORMS TO CONTINUE OVER THE NEXT FEW DAYS FROM  
THE SOUTHWEST INTO THE GREAT BASIN...  
 
...HAZARDOUS HEAT BUILDS ACROSS THE SOUTHERN PLAINS AND  
SOUTHEAST...  
 
AN UNSEASONABLY DEEP LOW PRESSURE SYSTEM CONTINUES A STEADY  
ADVANCE ACROSS THE UPPER GREAT LAKES THIS MORNING. OVER THE NEXT  
48 HOURS, A WELL DEFINED COLD FRONT PROTRUDING FROM THIS LOW  
CENTER IS EXPECTED TO PRESS SOUTHEASTWARD, WHICH WILL SET THE  
STAGE FOR ACTIVE SEVERE WEATHER AND FLASH FLOODING FROM THE  
MID-SOUTH INTO THE NORTHEAST AS A MOIST AND UNSTABLE AIRMASS POOLS  
AHEAD OF THE FRONT. SEVERE WIND GUSTS AND FLASH FLOODING ARE  
EXPECTED TO BE THE MAIN HAZARDS FROM ANY THUNDERSTORMS THIS  
AFTERNOON, ALTHOUGH SEVERE HAIL AND A FEW TORNADOES ARE ALSO  
POSSIBLE. BY TOMORROW, ANOTHER ROUND OF FLASH FLOODING AND SEVERE  
WEATHER IS POSSIBLE OVER PORTIONS OF THE LOWER MID-ATLANTIC AS THE  
FRONTAL BOUNDARY MIGRATES EASTWARD. MEANWHILE, ACROSS THE  
NORTHEAST GULF, TROPICAL STORM BERTHA IS EXPECTED TO CONTINUE A  
WESTWARD TRACK JUST SOUTH OF THE FLORIDA PANHANDLE TOWARDS  
SOUTHEAST LOUISIANA. MUCH OF THE RAINFALL WITH THIS SYSTEM IS  
STILL EXPECTED TO REMAIN SOUTH OF THE COASTLINE, ALTHOUGH THE  
OUTER BANDS OF BERTHA COULD STILL SUPPORT ISOLATED TO SCATTERED  
FLASH FLOODING OVER THE NEXT TWO DAYS. SEE THE LATEST NHC  
ADVISORIES FOR ADDITIONAL AND UPDATED INFORMATION ON THIS STORM.  
 
OVER INTO THE SOUTHWEST, MONSOONAL MOISTURE CIRCULATING AROUND THE  
WESTERN PERIPHERY OF THE RIDGE WILL CONTINUE TO SUPPORT SCATTERED  
AFTERNOON AND EVENING THUNDERSTORMS ACROSS THE CENTRAL AND  
SOUTHERN ROCKIES. STORM MOTIONS WILL GENERALLY REMAIN SLOW,  
PRODUCING LOCALLY HEAVY RAINFALL, ESPECIALLY OVER HIGHER TERRAIN  
THROUGH WEDNESDAY.  
 
TEMPERATURE WISE, A SUBTROPICAL RIDGE WILL MAINTAIN ANOMALOUS HEAT  
ACROSS THE SOUTHEAST AND SOUTHERN PLAINS, WHERE 105-115 DEGREE  
HEAT INDICES CAN BE EXPECTED. WITH THE ADDITION OF LITTLE  
OVERNIGHT RECOVERY, AS LOWS ARE EXPECTED TO DROP TO 75-80 F, HEAT  
RELATED ILLNESS WILL BE OF CONCERN OVER THE NEXT FEW DAYS,  
ESPECIALLY FOR THOSE WITHOUT ADEQUATE COOLING OR HYDRATION.  
FURTHER NORTH, BELOW NORMAL TEMPERATURES WILL BUILD BEHIND THE  
COLD FRONT, ACROSS THE UPPER MIDWEST/GREAT LAKES INTO THE  
NORTHEAST.  
 
ASHERMAN/OUDIT  
 
GRAPHICS AVAILABLE AT  
HTTPS://WWW.WPC.NCEP.NOAA.GOV/BASICWX/BASICWX_NDFD.PHP  
 
 
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