664
FOUS30 KWBC 240815
QPFERD
EXCESSIVE RAINFALL DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
415 AM EDT SUN MAY 24 2026
DAY 1
VALID 12Z SUN MAY 24 2026 - 12Z MON MAY 25 2026
...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL FROM THE CENTRAL
GULF COAST INTO NORTH GEORGIA AND ACROSS THE UPPER OHIO VALLEY...
THE WELL DEFINED MCV MOVING FROM SOUTHEAST LA INTO FAR SOUTHERN MS
EARLY THIS MORNING EXPECTED TO CONTINUE TO PUSH NORTHWARD DAY 1
ACROSS CENTRAL AL AND INTO NORTH GA. WHILE THE ORGANIZED CONVECTION
ASSOCIATED WITH THIS MCV MAY WEAKEN EARLY DAY 1, THERE IS POTENTIAL
FOR CONVECTION TO RE-FIRE AHEAD OF THIS MCV LATER THIS AFTERNOON
IN THE AXIS OF MUCH ABOVE AVERAGE PW VALUES, 2 TO 2.5+ STANDARD
DEVIATIONS ABOVE THE MEAN EXPECTED TO STRETCH FROM THE CENTRAL GULF
COAST, NORTHEASTWARD THROUGH THE SOUTHERN TO CENTRAL APPALACHIANS,
SOUTHEAST AND MID-ATLANTIC. WE ADDED A SLIGHT RISK FROM CENTRAL AL
INTO NORTH GA TO ACCOUNT FOR THIS CONVECTIVE POTENTIAL.
FARTHER TO THE SOUTHWEST...WE MADE SOME SIGNIFICANT CHANGES TO THE
PREVIOUS SLIGHT RISK AREA ACROSS SOUTHERN MS AND SOUTHERN LA. WE
SUPPRESSED THE SLIGHT, KEEPING IT JUST FOR FAR SOUTHEAST LA. THE
BEST INSTABILITY IN THE WAKE OF THE NORTHEASTWARD MOVING MCV WILL
BE OVER THE NORTHERN GULF, SUGGESTING THE HEAVIEST PRECIP WITH THE
NEXT ROUND OF CONVECTION ALSO BEING OFFSHORE. WE KEPT THE NEW
ORLEANS METRO AREA IN THE SLIGHT AS MODEL CONSENSUS IS FOR A NARROW
AXIS OF HEAVY RAINS TO EXTEND INTO FAR EASTERN LA.
ACROSS FL...THE MARGINAL RISK WAS EXTENDED SOUTH INTO PORTIONS OF
NORTH CENTRAL TO SOUTHWEST FL. MODEL CONSENSUS IS FOR ANOTHER ROUND
OF ACTIVE CONVECTION FORMING SUNDAY AFTERNOON IN A GENERAL NORTH TO
SOUTH AXIS. SLOW MOVING CELLS WILL AGAIN HAVE POTENTIAL FOR PRODUCE
LOCALLY HEAVY RAINFALL AMOUNTS AND ISOLATED RUNOFF ISSUES. THERE
WILL BE POTENTIAL FOR OVERLAP OF YESTERDAY'S HEAVY RAINFALL AMOUNTS
WITH SUNDAY AFTERNOON'S. THE BIGGEST RUNOFF THREAT WILL CONTINUE TO
BE IN MORE URBANIZED REGIONS.
OVER THE UPPER OHIO VALLEY...ADDED A SLIGHT RISK AREA FROM
NORTHEAST KY INTO EASTERN OH, NORTHWEST WV AND FAR SOUTHWEST PA.
BOTH THE HREF AND RRFS ARE SHOWING FAIRLY HIGH PROBABILITIES,
25-50%+ FOR 3 HOUR PRECIP AMOUNTS EXCEEDING FFG VALUES THIS
AFTERNOON INTO EARLY EVENING. FAVORABLE RIGHT ENTRANCE REGION JET
DYNAMICS IN THE ABOVE MENTIONED AXIS OF ANOMALOUS PW VALUES WILL
SUPPORT POTENTIAL FOR HEAVY PRECIP AND LOCALIZED RUNOFF ISSUES.
ORAVEC
DAY 2
VALID 12Z MON MAY 25 2026 - 12Z TUE MAY 26 2026
...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL FROM THE CENTRAL
GULF COAST TOWARD THE SOUTHERN APPALACHIANS...
AN AXIS OF ANOMALOUS PW VALUES, 2 TO 2.5+ STANDARD DEVIATIONS
ABOVE THE MEAN, WILL PERSIST FROM THE CENTRAL GULF COAST,
NORTHEASTWARD ACROSS THE SOUTH, SOUTHEAST AND SOUTHERN MID-ATLANTIC
DAY 2. THE CLOSED LOW OVER THE EASTERN PORTIONS OF THE SOUTHERN
PLAINS TOWARD THE LOWER MS VALLEY WILL MOVE ONLY VERY SLOWLY NORTH
NORTHEASTWARD DAY 2, KEEPING A FAVORABLE BROADLY UPPER DIFFLUENT
PATTERN TO ITS EAST IN THIS ANOMALOUS PW AXIS. THIS WILL SUPPORT
WIDESPREAD SCATTERED CONVECTION AND POTENTIAL FOR WIDESPREAD
MODERATE TO HEAVY PRECIP TOTALS. THERE IS A TYPICAL AMOUNT OF MODEL
QPF SPREAD, BUT CONSENSUS FOR POTENTIAL FOR WIDESPREAD MODERATE TO
HEAVY TOTALS. THERE WILL LIKELY BE OVERLAP BETWEEN THE DAY 1 AND
DAY 2 HEAVY PRECIP AREAS, ALTHOUGH LOW CONFIDENCE AT THE MOMENT
WITH DETAILS. NO SIGNIFICANT CHANGES MADE TO THE PREVIOUS OUTLOOKS
AREAS. MINOR ADJUSTMENTS MADE TO FIT THE LATEST MODEL QPF
CONSENSUS.
ORAVEC
DAY 3
VALID 12Z TUE MAY 26 2026 - 12Z WED MAY 27 2026
...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL FROM THE CENTRAL
GULF COAST TOWARD THE SOUTHERN APPALACHIANS AND ACROSS THE SOUTH
CENTRAL TEXAS...
NOT A LOT OF CHANGES TO THE WET PATTERN FROM THE CENTRAL GULF
COAST, NORTHEASTWARD ACROSS THE SOUTH, SOUTHEAST AND SOUTHERN
APPALACHIANS. THE AXIS OF ANOMALOUS PW VALUES, 2 TO 2.5+ STANDARD
DEVIATIONS ABOVE THE MEAN, WILL PERSIST ACROSS THIS AREA IN A
REGION OF PERSISTENT SOUTH SOUTHWESTERLY MID TO UPPER LEVEL FLOW ON
THE EAST SIDE OF THE WEAK MID TO UPPER LOW MOVING NORTH THROUGH THE
LOWER MS VALLEY. EXPECT ANOTHER DAY OF WIDESPREAD SCATTERED
CONVECTION AND WIDESPREAD MODERATE TO HEAVY RAINFALL TOTALS. WITH
NOT MUCH CHANGES OVERALL TO THE LARGE SCALE PATTERN, A SLIGHT RISK
WAS MAINTAINED IN A SIMILAR REGION AS DURING THE DAY 2 PERIOD.
THERE MAY AGAIN BE OVERLAP IN HEAVY RAIN AREAS DAY 3 WITH DAY 1 AND
2, WHICH MAY LEAD TO A UPGRADE IN THREAT CATEGORIES IN FUTURE
ISSUANCS.
MID TO UPPER LEVEL TROFFING DEVELOPING ACROSS THE SOUTHWEST DURING
DAY 2 WILL BE PUSHING HEIGHT FALLS INTO THE SOUTHERN PLAINS DAY 3.
INCREASINGLY ACTIVE CONVECTION LIKELY ACROSS THE SOUTHERN PLAINS
DAY 3, WITH MODEL CONSENSUS FOR WIDESPREAD MODERATE TO HEAVY
TOTALS. NOT A LOT OF CHANGES MADE TO THE PREVIOUS SLIGHT RISK AREA
OVER SOUTH CENTRAL TX. THIS REGION HAS SEEN SEVERAL ROUNDS OF
HEAVY PRECIP OVER THE PAST WEEK, LOWERING FFG VALUES AND INCREASING
THREAT OF ADDITIONAL RUNOFF ISSUES. THERE IS A LOT OF SPREAD WITH
QPF DETAILS, BUT A STRONG SIGNAL FOR HEAVY RAINFALL TOTALS DAY 3
ACROSS THIS AREA.
ORAVEC
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
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