026  
FXUS01 KWBC 212000  
PMDSPD  
 
SHORT RANGE FORECAST DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
359 PM EDT SAT JUL 21 2018  
 
VALID 00Z SUN JUL 22 2018 - 00Z TUE JUL 24 2018  
 
...SLIGHT RISK OF SEVERE WEATHER AND FLASH FLOODING POSSIBLE  
ACROSS THE SOUTHEAST U.S....  
 
...EXCESSIVE RAIN AND FLASH FLOODING POSSIBLE ACROSS PORTIONS OF  
THE OHIO VALLEY TODAY AS WELL AS ALONG THE MID AND NORTHERN  
ATLANTIC COAST THROUGH SUNDAY...  
 
...SEVERE WEATHER POSSIBLE ACROSS THE NORTHERN HIGH PLAINS AND  
PORTIONS OF WISCONSIN THROUGH THE REST OF THE WEEKEND...  
 
...ABOVE NORMAL TEMPERATURES TO CONTINUE ACROSS MUCH OF THE  
SOUTH-CENTRAL AND SOUTH-WEST UNITED STATES, AS WELL AS ACROSS  
PORTIONS OF THE NORTHWEST...  
 
THE FRONTAL SYSTEM THAT HAS BEEN IMPACTING THE MISSISSIPPI,  
TENNESSEE AND OHIO VALLEYS WILL CONTINUE TO PUSH SOUTHEASTWARD  
THROUGH THE REST OF THE WEEKEND. SHOWERS AND THUNDERSTORMS WILL  
CONTINUE ALONG THIS FRONT AIDED BY COPIOUS AMOUNTS OF MOISTURE AND  
INSTABILITY. THE STORM PREDICTION CENTER HAS INDICATED THAT SEVERE  
WEATHER WILL BE A CONCERN ESPECIALLY IN THE SOUTHEAST AND THE  
SOUTHERN APPALACHIANS THROUGH TONIGHT. THE THREAT FOR SEVERE  
WEATHER WILL THEN CONTINUE INTO SUNDAY ACROSS NORTHERN FLORIDA AND  
PORTIONS OF SOUTHERN MISSISSIPPI AND ALABAMA. THE LOW PRESSURE  
SYSTEM THAT HAS SPAWNED THIS ACTIVITY WILL REMAIN PARKED ACROSS  
THE OHIO VALLEY THROUGH MONDAY, LEADING TO THE CONTINUED CHANCE OF  
SHOWERS AND THUNDERSTORMS ACROSS THE OHIO VALLEY, MID-ATLANTIC,  
AND SOUTHEAST DURING THIS TIME.  
 
MEANWHILE, A SURFACE LOW THAT HAS FORMED OFF THE COAST OF THE  
CAROLINAS WILL ALSO BE PUSHING NORTHWARD ALONG THE MID-ATLANTIC  
COAST AND TOWARDS THE NORTHEAST THROUGH TONIGHT. THIS SYSTEM WILL  
BE A FOCAL POINT FOR HEAVY RAINFALL, PARTICULARLY ALONG THE  
COASTAL REGIONS. THUS, THE WEATHER PREDICTION CENTER HAS ISSUED A  
SLIGHT RISK OF EXCESSIVE RAINFALL/FLASH FLOODING FOR COASTAL  
REGIONS OF THE MID-ATLANTIC THROUGH TONIGHT AND FOR COASTAL  
REGIONS OF THE NORTHEAST FOR SUNDAY.  
 
A FRONTAL SYSTEM WILL SLIDE ACROSS THE NORTHERN HIGH PLAINS  
THROUGH SUNDAY, PRODUCING A LINE OF SHOWERS AND THUNDERSTORMS AS  
IT TRAVERSES EASTWARD. A SLIGHT RISK OF SEVERE WEATHER AND  
EXCESSIVE RAINFALL IS POSSIBLE, ESPECIALLY IN EASTERN  
MONTANA/WYOMING AND WESTERN PORTIONS OF THE DAKOTAS THROUGH  
TONIGHT. THE SLIGHT RISK OF SEVERE WEATHER THEN SHIFTS EASTWARD  
INTO THE EASTERN NORTHERN PLAINS AND PORTIONS OF MINNESOTA FOR  
SUNDAY. A MARGINAL RISK OF FLOODING WILL ALSO BE POSSIBLE FOR  
COLORADO WHERE SOME THUNDERSTORMS COULD PRODUCE FLASH FLOODING IN  
FAVORABLE TERRAIN.  
 
DANGEROUS HEAT REMAINS IN PLACE ACROSS THE SOUTHERN PLAINS, LOWER  
MISSISSIPPI VALLEY, SOUTHWEST, CALIFORNIA, AND EVEN INTO THE  
WESTERN NORTHERN PLAINS. THIS HEAT IS EXPECTED TO REMAIN IN PLACE  
THROUGH AT LEAST MONDAY. EXCESSIVE HEAT WATCHES, WARNINGS AND HEAT  
ADVISORIES ARE IN PLACE ACROSS THESE REGIONS. HIGH TEMPERATURES  
WILL REACH WELL OVER THE CENTURY MARK ACROSS TEXAS AND OKLAHOMA  
THROUGH THIS WEEKEND--WITH AREAS NEAR THE DALLAS/FORT WORTH REGION  
REACHING UP TO 110 DEGREES! PORTIONS OF THE RED RIVER VALLEY COULD  
HAVE HEAT INDEX VALUES EVEN HOTTER, IN EXCESS OF 110 DEGREES.  
PORTIONS OF THE PACIFIC NORTHWEST WILL ALSO CONTINUE TO EXPERIENCE  
ABOVE NORMAL TEMPERATURES--ESPECIALLY BY THE END OF THE WEEKEND  
WHERE TEMPERATURES COULD REACH THE MID TO UPPER 90S AND EVEN REACH  
OVER 100 IN SOME AREAS.  
 
WIX  
 
GRAPHICS AVAILABLE AT  
WWW.WPC.NCEP.NOAA.GOV/BASICWX/BASICWX_NDFD.PHP  

 
 
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