525  
FXUS01 KWBC 231903  
PMDSPD  
 
SHORT RANGE FORECAST DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
303 PM EDT MON SEP 23 2024  
 
VALID 00Z TUE SEP 24 2024 - 00Z THU SEP 26 2024  
 
...MUCH NEEDED RAINS POSSIBLE FROM THE OHIO VALLEY INTO THE  
CENTRAL TO SOUTHERN APPALACHIANS, UPPER TENNESSEE VALLEY AND  
MID-ATLANTIC...  
 
...RAINS FROM THE DEVELOPING TROPICAL SYSTEM IN THE WESTERN  
CARIBBEAN MAY BEGIN TO AFFECT THE FLORIDA KEYS AND SOUTH FLORIDA  
ON WEDNESDAY...  
 
...MUCH ABOVE AVERAGE TEMPERATURES CONTINUE ACROSS THE WEST INTO  
THE NORTHERN PLAINS AND ACROSS THE GULF COAST INTO THE SOUTHEAST...  
 
THE LARGE SCALE MID TO UPPER LEVEL FLOW ACROSS THE LOWER 48 WILL  
CONTINUE TO AMPLIFY OVER THE NEXT FEW DAYS, COMPRISED OF A  
DEEPENING UPPER TROF FROM THE EASTERN PORTIONS OF THE PLAINS INTO  
THE MISSISSIPPI VALLEY, A BUILDING UPPER RIDGE ACROSS THE INTERIOR  
WEST AND THE STRENGTHENING AND RE-POSITIONING OF AN UPPER RIDGE  
OFF THE SOUTHEAST COAST. THIS AMPLIFICATION WILL BE LEADING TO  
IMPACTFUL WEATHER EVENT OVER THE NEXT SEVERAL DAYS ACROSS LARGE  
PORTIONS OF THE U.S.  
 
THE INITIAL IMPACTS WILL BE IN THE FORM OF AN EXPANDING AREA OF  
MODERATE TO HEAVY RAINFALL POTENTIAL FROM THE MID-WEST INTO THE  
LOWER LAKES, OHIO VALLEY, UPPER TENNESSEE VALLEY, CENTRAL TO  
SOUTHERN APPALACHIANS INTO THE MID-ATLANTIC. MUCH OF THESE AREAS  
ARE CURRENTLY EXPERIENCING SEVERE TO EXCEPTIONAL DROUGHT  
CONDITIONS, WITH THE EXPECTED 1 TO 1.5 INCH PLUS RAINFALL AMOUNT  
OVER THE NEXT TWO DAYS BRINGING SOME RELIEF TO THESE DROUGHT  
CONDITIONS. WITH THE DRY CONDITIONS ACROSS THESE AREAS, RIVER  
FLOODING WILL BE UNLIKELY. HOWEVER, THERE IS STILL AT LEAST A  
MARGINAL RISK OF ISOLATED FLASH FLOODING WITH THE EXPECTED HEAVY  
RAINFALL AMOUNTS, ESPECIALLY IF THEY OCCUR OVER URBANIZED REGIONS.  
 
MORE SIGNIFICANT IMPACTS TO THE ABOVE MENTIONED AMPLIFYING PATTERN  
WILL BE THE WEAKENING OF THE MID TO UPPER LEVEL RIDGE ACROSS THE  
GULF COAST AS THE UPPER TROF AMPLIFIES OVER THE LOWER MISSISSIPPI  
VALLEY AND THE UPPER RIDGE REBUILDS OFF THE SOUTHEAST. THIS IN  
TURN WILL BE CREATING A PATH IN THE ATMOSPHERE, BETWEEN THE  
AMPLIFYING UPPER TROF OVER THE LOWER MISSISSIPPI VALLEY AND THE  
RE-POSITIONING UPPER RIDGE OFF THE SOUTHEAST COAST, FOR THE  
NORTHWEST MOVEMENT OF THE DEVELOPING TROPICAL SYSTEM OVER THE  
NORTHWEST CARIBBEAN TOWARD THE YUCATAN STRAITS TUESDAY INTO EARLY  
WEDNESDAY, AND THEN A MORE NORTH NORTHEAST TRACK INTO THE EASTERN  
GULF WEDNESDAY INTO THURSDAY. WHILE THE CURRENT OFFICIAL TRACK OF  
THIS SYSTEM FROM THE NATIONAL HURRICANE CENTER KEEPS THE CENTER OF  
THE STORM WELL TO THE WEST OF THE FLORIDA KEYS, THE OUTER BANDS OF  
PRECIPITATION AND SQUALLY WEATHER ON THE EAST SIDE OF THE STORM  
MAY BEGIN TO AFFECT THE FLORIDA KEYS AND SOUTH FLORIDA ON  
WEDNESDAY. ADDITIONAL MAJOR IMPACTS FROM THIS STORM LIKELY ACROSS  
PORTIONS OF FLORIDA INTO THE SOUTHEAST THURSDAY AND FRIDAY.  
PLEASE REFER TO THE NATIONAL HURRICANE CENTER FOR THE LATEST  
UPDATES ON THIS SYSTEM.  
 
THE AMPLIFYING UPPER RIDGE ACROSS THE INTERIOR WEST WILL BE  
SUPPORTING WIDESPREAD MUCH ABOVE AVERAGE TEMPERATURES OVER THE  
NEXT FEW DAYS ACROSS NEARLY ALL OF THE WEST AND INTO THE NORTHERN  
PLAINS. HIGH TEMPERATURES ACROSS THESE REGIONS ARE FORECAST TO BE  
AS MUCH AS 10 TO 20 DEGREES ABOVE AVERAGE. ABOVE AVERAGE  
TEMPERATURES ALSO LIKELY ACROSS THE GULF COAST AND INTO THE  
SOUTHEAST. WHILE TEMPERATURES ARE FORECAST TO BE MUCH ABOVE  
ACROSS THESE AREAS OVER THE NEXT FEW DAYS, THERE ARE NOT EXPECTED  
TO BE MANY RECORD HIGHS. HOWEVER, MORE NUMEROUS RECORD HIGH  
MORNING TEMPERATURES ARE POSSIBLE BOTH TUESDAY AND WEDNESDAY  
MORNING ALONG THE WEST COAST AND FROM PORTIONS OF THE SOUTHERN  
MID-ATLANTIC INTO THE SOUTHEAST AND FLORIDA.  
 
ORAVEC  
 
GRAPHICS AVAILABLE AT  
HTTPS://WWW.WPC.NCEP.NOAA.GOV/BASICWX/BASICWX_NDFD.PHP  
 

 
 
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