574  
FOUS30 KWBC 031951  
QPFERD  
 
EXCESSIVE RAINFALL DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
351 PM EDT SUN MAY 3 2026  
 
DAY 1  
VALID 16Z SUN MAY 03 2026 - 12Z MON MAY 04 2026  
 
...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL OVER PORTIONS OF  
THE SOUTHEAST FLORIDA PENINSULA...  
 
16Z UPDATE... REDEVELOPMENT OF CONVECTION EXPECTED ROUGHLY IN THE  
18Z-01Z WINDOW TO PASS THROUGH OVER THE URBAN CORRIDOR WITH HOURLY  
RATES UP TO 2 INCHES/HOURS. THIS WILL MAINTAIN AN ELEVATED THREAT  
FOR EXCESSIVE RAINFALL AND ISOLATED AREAS OF FLASH FLOODING. THE  
NORTHERN EDGE OF THE MARGINAL WAS EXTENDED NORTHWARD TO COVER MOST  
OF PALM BEACH COUNTY.  
 
CAMPBELL  
 
JUST ENOUGH OF A SIGNAL IN THE 03/00Z CAMS TO MAINTAIN THE MARGINAL  
RISK AREA. THE FOCUS WILL BE OVER THE URBAN SOUTHEAST COAST AS A  
FRONT ADVANCES INTO A REGION OF DEEPER MOISTURE AND WHERE CAPE  
TENDS TO BE UNDER 1000 J PER KG. THE 03/00Z HREF DOES DEPICT A  
LOW-END NEIGHBORHOOD PROBABILITY OF FFGS BEING EXCEEDED OVER THE  
SOUTHERN TIP OF THE FLORIDA PENINSULA IN THE 03/21Z TO 04/00Z  
PERIOD BUT THE STRONGER SIGNALS IN THE GUIDANCE IS FOR HEAVIER  
RAINFALL TO BE HUGGING THE COAST OR REMAINING JUST OFF-SHORE. IT  
WAS NOTED THAT OVER THE PAST COUPLE OF DAYS...NUMERICAL MODELS HAVE  
BEEN CUTTING BACK THE AMOUNT OF MOISTURE IN THE LOWEST LAYERS WHICH  
 
BANN  
 
DAY 2  
VALID 12Z MON MAY 04 2026 - 12Z TUE MAY 05 2026  
 
THE PROBABILITY OF RAINFALL EXCEEDING FLASH FLOOD GUIDANCE IS LESS  
THAN 5 PERCENT.  
 
CAMPBELL  
 
DAY 3  
VALID 12Z TUE MAY 05 2026 - 12Z WED MAY 06 2026  
 
...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL OVER PORTIONS OF  
THE MID MISSISSIPPI VALLEY INTO THE OHIO VALLEY...  
 
21Z UPDATE... NO ADJUSTMENTS WERE MADE TO THE CURRENT MARGINAL RISK  
AREA. STILL EXPECTING A SOUTHWEST TO NORTHEAST AXIS OF RAINFALL TO  
ALIGN AHEAD OF AND ALONG A COLD FRONT FROM ARKANSAS TO WESTERN NEW  
YORK. AREAL AVERAGES OF 1 TO 2.5 INCHES WITH THE HIGHER END  
GENERALLY FOCUSING WITHIN THE OHIO VALLEY. IN GENERAL THIS WILL BE  
A BENEFICIAL RAIN HOWEVER THERE MAY BE ISOLATED AREAS WHERE  
RAIN RATES LEAD TO LOCAL FLASH FLOODING.  
 
CAMPBELL  
 
DEEP LAYER SOUTHWESTERLY FLOW LEADING INTO THE START OF THE PERIOD  
WILL BE DRAWING MOISTURE INTO PARTS OF THE PLAINS AND THEN  
DOWNSTREAM TOWARD THE GREAT LAKES AND THE OHIO VALLEY. AS A TROUGH  
AMPLIFIES OVER THE CENTRAL PART OF NORTH AMERICA AND A JET STREAK  
FORMS OVER THE SOUTHWEST US AND APPROACHES THE PLAINS...THE CHANCE  
FOR SHOWERS AND THUNDERSTORMS INCREASES ALONG AND AHEAD OF A  
DEVELOPS SURFACE FRONT. WITH PRECIPITABLE WATER VALUES OF 1.75 TO  
1.9 INCHES EMBEDDED WITHIN A BROADER 1.5 TO 1.75 AREA...WHICH WAS  
PUSHING TWO STANDARDIZED ANOMALIES GREATER THAN CLIMATOLOGY FOR  
THIS TIME OF YEAR--LOCALLY HEAVY RAINFALL AND THE ASSOCIATED RISK  
OF LOCALIZED FLOODING FROM LATE TUESDAY AFTERNOON INTO EARLY  
WEDNESDAY IS POSSIBLE.  
 
BANN  
 
DAY 1 THREAT AREA: HTTPS://WWW.WPC.NCEP.NOAA.GOV/QPF/94EPOINTS.TXT  
DAY 2 THREAT AREA: HTTPS://WWW.WPC.NCEP.NOAA.GOV/QPF/98EPOINTS.TXT  
DAY 3 THREAT AREA: HTTPS://WWW.WPC.NCEP.NOAA.GOV/QPF/99EPOINTS.TXT  
CLICK HERE TO GO TO PREVIOUS BULLETINS.
The Nexlab HPC Page
Main Text Page