549  
FXUS01 KWBC 181956  
PMDSPD  
 
SHORT RANGE FORECAST DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
355 PM EDT SUN AUG 18 2024  
 
VALID 00Z MON AUG 19 2024 - 00Z WED AUG 21 2024  
 
...SEVERE THUNDERSTORMS AND FLASH FLOODING ARE EXPECTED FOR  
PORTIONS OF THE MID-ATLANTIC INTO THE NORTHEAST THROUGH MONDAY...  
 
...SOME RELIEF EXPECTED FOR THE CENTRAL GULF COAST EARLY THIS WEEK  
BUT DANGEROUS HEAT AND HUMIDITY TO CONTINUE ACROSS THE SOUTHERN  
PLAINS...  
 
...INCREASED RISK FOR SPREADING OF WILDFIRES FROM CENTRAL NEVADA  
INTO SOUTHEASTERN OREGON THROUGH TUESDAY...  
 
A SLOW MOVING COLD FRONT, EXTENDING FROM WESTERN NEW  
YORK/PENNSYLVANIA INTO THE GULF COAST STATES, WILL GRADUALLY  
TRANSLATE EAST OVER THE NEXT ONE TO TWO DAYS, CLEARING A MAJORITY  
OF THE EAST COAST BY TUESDAY MORNING. ALONG AND AHEAD OF THE COLD  
FRONT, ANOMALOUS MOISTURE AND THUNDERSTORMS REPEATING OVER THE  
SAME LOCATIONS WILL POSE A THREAT FOR FLASH FLOODING WITH THE  
GREATEST FLASH FLOOD CONCERN FROM THE NORTHERN MID-ATLANTIC INTO  
SOUTHERN NEW ENGLAND THIS EVENING AND TONIGHT. SEVERE  
THUNDERSTORMS WILL ALSO BE POSSIBLE AHEAD OF THE COLD FRONT WITH  
THE GREATEST RISK BEING STRAIGHT LINE WINDS, EXTENDING FROM THE  
NORTHERN MID-ATLANTIC INTO THE SOUTHEAST, GULF COAST STATES AND  
PORTIONS OF THE CENTRAL PLAINS THROUGH MONDAY MORNING. CONDITIONS  
WILL IMPROVE IN THE WAKE OF THE COLD FRONT WITH A SIGNIFICANT  
COOLING TREND FOR THE MIDWEST AND NORTHEAST THROUGH TUESDAY WITH  
HIGH TEMPERATURES FORECAST TO BE 10 TO 20 DEGREES BELOW MID-AUGUST  
AVERAGES.  
 
HIGH HEAT AND SURFACE DEWPOINTS WILL PERSIST ACROSS THE SOUTHERN  
U.S. BENEATH THE INFLUENCE OF AN UPPER LEVEL RIDGE CENTERED OVER  
THE SOUTHERN HIGH PLAINS THROUGH AT LEAST MID-WEEK. EXCESSIVE HEAT  
WARNINGS AND HEAT ADVISORIES ARE ALREADY IN PLACE FROM SOUTHERN  
KANSAS INTO OKLAHOMA AND TEXAS, EASTWARD TO THE CENTRAL GULF  
COAST. DAYTIME TEMPERATURES COMBINED WITH HIGH HUMIDITY WILL  
RESULT IN HEAT INDEX VALUES RANGING FROM 105 TO LOCALLY OVER 115  
DEGREES FOR PORTIONS OF THE REGION. A SOUTHWARD SAGGING COLD FRONT  
WILL BRING COOLER TEMPERATURES INTO THE LOWER MISSISSIPPI VALLEY  
BEGINNING TOMORROW AND CONTINUING INTO TUESDAY, BUT THE HEAT WILL  
REMAIN THROUGH AT LEAST MID-WEEK FOR TEXAS, EVENTUALLY SPREADING  
INTO NEW MEXICO.  
 
OUT WEST, ANOTHER SLOW MOVING COLD FRONT, LOCATED OVER THE  
INTERIOR OF THE NORTHWEST, WILL REMAIN NEARLY STATIONARY UNTIL  
TUESDAY. TEMPERATURES FROM NORTHERN CALIFORNIA INTO OREGON AND  
WASHINGTON (WEST OF THE BOUNDARY) WILL EXPERIENCE HIGH  
TEMPERATURES ROUGHLY 5 TO 15 DEGREES BELOW AVERAGE ALONG WITH SOME  
RAIN FOR WESTERN WASHINGTON. EAST OF THE BOUNDARY HOWEVER, HOT  
TEMPERATURES WILL NOT BE THE BIG CONCERN BUT RATHER DRY AND WINDY  
CONDITIONS FAVORING INCREASED RISKS FOR WILDFIRES FROM CENTRAL  
NEVADA INTO SOUTHEASTERN OREGON AND ADJACENT LOCATIONS. DUE TO THE  
SLOW MOVEMENT OF THE UPPER PATTERN, THESE CONDITIONS WILL REMAIN  
IN PLACE FOR MULTIPLE DAYS.  
 
THE SOUTHWESTERN U.S. WILL SEE MONSOONAL MOISTURE CONTINUING TO  
FAVOR A RISK FOR SHORT TERM HEAVY RAIN CAPABLE OF LOCALIZED TO  
SCATTERED AREAS OF FLASH FLOODING. THE FLASH FLOOD RISK WILL  
OVERLAP WITH A RISK OF SEVERE THUNDERSTORMS FROM UTAH AND PORTIONS  
OF EASTERN IDAHO AND WESTERN WYOMING THIS EVENING, WITH THE  
OVERLAPPING RISK EXTENDING EAST INTO EAST-CENTRAL COLORADO FOR  
MONDAY. ON TUESDAY, THE THREATS FOR SEVERE THUNDERSTORMS AND FLASH  
FLOODING APPEAR LOWER BUT A LOCALIZED THREAT WILL REMAIN FOR THE  
DESERT SOUTHWEST INTO PORTIONS OF MONTANA AHEAD OF THE  
AFOREMENTIONED COLD FRONT.  
 
OTTO  
 
GRAPHICS AVAILABLE AT  
HTTPS://WWW.WPC.NCEP.NOAA.GOV/BASICWX/BASICWX_NDFD.PHP  
 
 
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