738  
FXUS01 KWBC 132022  
PMDSPD  
 
SHORT RANGE FORECAST DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
421 PM EDT MON AUG 13 2018  
 
VALID 00Z TUE AUG 14 2018 - 00Z THU AUG 16 2018  
 
...HEAVY RAIN POSSIBLE OVER THE NORTHERN MID ATLANTIC AND  
NORTHEAST...  
 
...HEAVY RAIN POSSIBLE OVER THE SOUTHERN PLAINS THIS  
AFTERNOON/TONIGHT, STRETCHING INTO THE MIDDLE MISSISSIPPI VALLEY  
ON TUESDAY...  
   
..FIRE WEATHER CONCERNS CONTINUE ACROSS THE WESTERN U.S.
 
 
A QUASI-STATIONARY FRONT EXTENDING ALONG THE COAST OF THE NEW  
ENGLAND, THE MID-ATLANTIC AND SOUTHEAST WILL RESULT IN CHANCES OF  
SHOWERS AND THUNDERSTORMS THROUGH THE NEXT COUPLE DAYS. A SURFACE  
LOW PRESSURE SYSTEM EMBEDDED IN THIS FRONTAL SYSTEM, COMBINED WITH  
A STRONG UPPER LEVEL LOW, WILL ALLOW FOR STRONG MOISTURE ADVECTION  
INTO THE NORTHERN MID ATLANTIC AND SOUTHERN NEW ENGLAND, WHERE  
RAIN AND THUNDERSTORMS WILL BE LIKELY TODAY THROUGH TUESDAY. THE  
WEATHER PREDICTION CENTER HAS ISSUED A SLIGHT RISK OF EXCESSIVE  
RAINFALL AND FLASH FLOODING IN THIS REGION THROUGH TONIGHT.  
FURTHERMORE, EASTERN PENNSYLVANIA, SOUTHERN NEW YORK, AND  
NORTHWEST NEW JERSEY ARE OUTLINED IN A MODERATE RISK THROUGH  
TONIGHT, HIGHLIGHTING THAT RAIN AND FLASH FLOOD POTENTIAL WILL BE  
GREATEST IN THIS AREA. FLASH FLOOD WATCHES AND WARNINGS ARE ALSO  
CURRENTLY IN EFFECT THIS AFTERNOON FOR THIS REGION AS WELL. THE  
THREAT FOR FLASH FLOODING WILL TAPER OFF THROUGH THE DAY TUESDAY  
AS THE UPPER LEVEL LOW DRIVING THIS SYSTEM SHIFTS INLAND AND LOSES  
STRENGTH, BECOMING AN OPEN WAVE.  
 
MEANWHILE, THE SOUTHERN EXTENT OF THE ABOVE MENTIONED FRONTAL  
SYSTEM WILL STRETCH BACK INTO THE SOUTHERN PLAINS WHERE IT WILL  
COMBINE WITH ANOTHER SURFACE LOW PRESSURE FEATURE AND STRONG UPPER  
LEVEL SYSTEM. THIS WILL RESULT IN STRONG ADVECTION OF WARM AND  
MOIST AIR INTO THE SOUTHERN AND CENTRAL PLAINS FROM THE GULF OF  
MEXICO, PRODUCING SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS.  
THESE WILL SLOWLY SHIFT EASTWARD THROUGH AT LEAST MID-WEEK AS THE  
SURFACE AND UPPER LEVEL LOW ALSO MAKE A SLOW EASTWARD PROGRESSION.  
THE WEATHER PREDICTION CENTER HAS OUTLINED A PORTION OF THE  
CENTRAL AND SOUTHERN PLAINS AS BEING IN A SLIGHT RISK FOR  
EXCESSIVE RAINFALL AND FLASH FLOODING THROUGH TONIGHT. THIS AREA  
WILL TRANSITION SLIGHTLY EASTWARD AND ENCOMPASS A PORTION OF THE  
MIDDLE MISSISSIPPI VALLEY FOR TUESDAY AND TUESDAY NIGHT, AND THEN  
CONTINUE INTO THE MIDDLE MISSISSIPPI AND OHIO VALLEY FOR WEDNESDAY  
AND WEDNESDAY NIGHT. A FLASH FLOOD WATCH IS CURRENTLY IN PLACE  
ACROSS WESTERN OKLAHOMA AND FAR NORTHWEST ARKANSAS.  
 
ELSEWHERE, AIR QUALITY ALERTS ALSO REMAIN IN PLACE ACROSS A LARGE  
PORTION OF CENTRAL CALIFORNIA AS WELL AS ACROSS INLAND WASHINGTON  
AND NORTHERN IDAHO AS WILDFIRES CONTINUE TO INFUSE THE AIR WITH  
COPIOUS AMOUNTS OF SMOKE. RED FLAG WARNINGS AND FIRE WEATHER  
WATCHES ARE ALSO IN EFFECT FOR MUCH OF NEVADA, AS WELL AS PORTIONS  
OF SOUTHERN WYOMING. WEAK MONSOONAL MOISTURE AND DAYTIME HEATING  
WILL AID IN PRODUCING SHOWERS AND THUNDERSTORMS OVER PARTS OF THE  
SOUTHWEST/GREAT BASIN AND THE SOUTHERN/CENTRAL ROCKIES THROUGH  
THIS EVENING.  
 
WIX  
 
GRAPHICS AVAILABLE AT  
WWW.WPC.NCEP.NOAA.GOV/BASICWX/BASICWX_NDFD.PHP  

 
 
CLICK HERE TO GO TO PREVIOUS BULLETINS.

The Nexlab HPC Page Main Text Page