854  
FXUS01 KWBC 182000  
PMDSPD  
 
SHORT RANGE FORECAST DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
359 PM EDT WED JUL 18 2018  
 
VALID 00Z THU JUL 19 2018 - 00Z SAT JUL 21 2018  
 
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PARTS OF  
THE CENTRAL PLAINS...  
 
...HEAVY RAIN POSSIBLE OVER PARTS OF THE UPPER MISSISSIPPI AND THE  
MIDDLE MISSOURI VALLEYS...  
 
...HEAVY RAIN POSSIBLE OVER PARTS OF THE SOUTHEAST COAST AND THE  
EASTERN GULF COAST...  
 
A QUASI-STATIONARY FRONT EXTENDING FROM THE SOUTHERN MID-ATLANTIC  
INTO PARTS OF THE SOUTHERN PLAINS WILL SLOWLY DISSIPATE OVER THE  
SOUTHERN PLAINS/LOWER MISSISSIPPI VALLEY BY THURSDAY NIGHT, WHILE  
THE BOUNDARY OVER THE SOUTHEAST REMAINS BUT STALLS. THIS FRONT  
WILL BE THE EPICENTER FOR SHOWER AND THUNDERSTORM DEVELOPMENT  
ACROSS THE SOUTHEAST AND SOUTHERN MID-ATLANTIC COAST THROUGH THE  
END OF THE WORK WEEK.  
 
MEANWHILE, A LOW PRESSURE SYSTEM CURRENTLY OVER THE CENTRAL PLAINS  
WILL CONTINUE TO DEEPEN AS IT SHIFTS EAST-NORTHEASTWARD THROUGH  
THE NORTHERN PLAINS AND TOWARDS THE UPPER MISSISSIPPI VALLEY BY  
THE END OF THE WORK WEEK. AS THIS LOW DEEPENS, A STRONG PULL OF  
WARM, MOIST AIR FROM THE GULF OF MEXICO WILL RESULT IN THE  
DEVELOPMENT OF A FAIRLY STRONG WARM FRONT, AND THEN EVENTUALLY A  
COLD FRONT. THIS SYSTEM WILL ALSO BE THE EPICENTER FOR SHOWER AND  
THUNDERSTORM DEVELOPMENT ACROSS THIS REGION. THE STORM PREDICTION  
CENTER HAS OUTLINED AN ENHANCED RISK FOR SEVERE THUNDERSTORM  
DEVELOPMENT ACROSS PORTIONS OF THE CENTRAL AND NORTHERN PLAINS FOR  
THIS AFTERNOON THROUGH TONIGHT. A MARGINAL AND SLIGHT RISK HAVE  
ALSO BEEN OUTLINED ACROSS PORTIONS OF THE MID MISSISSIPPI VALLEY  
FOR THURSDAY, SHIFTING EASTWARD INTO THE OHIO VALLEY FOR FRIDAY  
AHEAD OF THE DEVELOPING COLD FRONT. EXCESSIVE RAINFALL AND FLASH  
FLOODING WILL ALSO BE POSSIBLE WITH THESE STORMS. THE WEATHER  
PREDICTION CENTER HAS ALSO OUTLINED PORTIONS OF THE NORTHERN  
MISSOURI RIVER BASIN AS BEING IN A MARGINAL TO SLIGHT RISK OF  
EXCESSIVE RAINFALL THIS AFTERNOON AND TONIGHT. PORTIONS OF THE  
UPPER MISSISSIPPI RIVER VALLEY HAVE A MARGINAL TO SLIGHT CHANCE OF  
EXCESSIVE RAINFALL ON THURSDAY AS WELL.  
 
IN ADDITION TO THE THUNDERSTORM AND EXCESSIVE RAINFALL CONCERNS,  
HEAT IS ALSO IMPACTING MANY STATES ACROSS THE U.S. A STRONG PULL  
OF WARM AIR INTO THE CENTRAL PORTION OF THE UNITED STATES IS  
CURRENTLY LEADING TO WELL ABOVE NORMAL TEMPERATURES IN ADDITION TO  
HIGH HUMIDITY VALUES. THIS WILL ONLY INCREASE AS THE ABOVE  
MENTIONED LOW PRESSURE SYSTEM CONTINUES TO GAIN STRENGTH. PORTIONS  
OF THE SOUTHERN PLAINS, AS WELL AS SOME LOCATIONS IN NEBRASKA AND  
MISSOURI ARE UNDER HEAT ADVISORIES AND WARNINGS THROUGH THE END OF  
THE WORK WEEK AS A RESULT. FURTHERMORE, MUCH OF THE WESTERN UNITED  
STATES IS ALSO FEELING THE EFFECTS OF EXCESSIVE HEAT. EXCESSIVE  
HEAT WATCHES, ADVISORIES, AND WARNINGS ARE ALL IN EFFECT ACROSS  
CALIFORNIA, PORTIONS OF THE EXTREME SOUTHEAST, AND THE CENTRAL  
GREAT BASIN. WIND IS AIDING TO THE PROBLEM FARTHER NORTH, WITH RED  
FLAG WARNINGS POSTED ACROSS PORTIONS OF THE NORTHWEST AND INTO THE  
NORTHERN ROCKIES.  
 
ZIEGENFELDER  
 
GRAPHICS AVAILABLE AT  
WWW.WPC.NCEP.NOAA.GOV/BASICWX/BASICWX_NDFD.PHP  

 
 
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