966
FXUS62 KRAH 110813
AFDRAH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
410 AM EDT SUN MAY 11 2025
SYNOPSIS
HIGH PRESSURE WILL PUSH OFF THE MID ATLANTIC AND NORTHEAST COAST
TODAY. A SLOW MOVING UPPER LOW CENTERED OVER LOUISIANA THIS MORNING
WILL DRIFT NORTHEAST THROUGH THE MID SOUTH TO THE CENTRAL
APPALACHIANS THROUGH WEDNESDAY, BRINGING WET AND UNSETTLED WEATHER
TO THE CAROLINAS.
NEAR TERM /TODAY THROUGH TONIGHT/
AS OF 250 AM SUNDAY...
A CLOSED UPPER LOW CURRENTLY OVER THE SOUTHERN MISS VALLEY AND THE
MOIST DEEP SOUTHERLY FLOW ON ITS EAST SIDE WILL BE THE PRIMARY
INFLUENCE ON OUR WX TODAY. THE RAIN THAT'S CURRENTLY SEEN ON
REGIONAL RADAR TO OUR SOUTH IS PROGGED TO LIFT NORTHWARD THIS
MORNING REACHING OUR SOUTHERN PIEDMONT AND TRIAD ZONES SHORTLY AFTER
DAYBREAK, THEN CONTINUING TO LIFT NORTH REACHING THE TRIANGLE BY
EARLY AFTERNOON. AFTER A SEVERAL HOUR PERIOD OF MAINLY LIGHT RAIN
FALLING ACROSS AREAS TO THE SOUTH AND WEST OF RDU, NEARLY ALL
MEMBERS OF THE HREF SHOW THIS BAND OF RAIN DISSIPATING AS IT
CONTINUES TO MOVE NORTHWARD INTO A MUCH DRIER AND MORE STABLE
AIRMASS ASSOCIATED WITH HIGH PRESSURE TO OUR NORTH. HIGHS TODAY,
LARGELY INFLUENCED BY CLOUDS AND RAIN, WILL BE HELD IN THE UPPER 60S
ACROSS THE TRIAD AND LOWER 70S ELSEWHERE.
A LULL IN THE RAIN IS EXPECTED ACROSS MUCH OF CENTRAL NC THIS
EVENING AND EARLY OVERNIGHT BEFORE THE NEXT ROUND OF MORE VIGOROUS
RAIN BREAKS OUT DURING THE PRE-DAWN HOURS MONDAY MORNING ASSOCIATED
WITH A POWERFUL JET STREAK LIFTING NORTH ON THE DOWNWIND SIDE OF THE
UPPER TROUGH. LOWS TONIGHT IN THE UPPER 50S TO LOWER 60S.
SHORT TERM /MONDAY AND MONDAY NIGHT/
AS OF 300 AM SUNDAY...
* A FLASH FLOOD WATCH HAS BEEN ISSUED FOR ALL OF CENTRAL NC FROM
EARLY-MORNING MON THROUGH DAYBREAK TUE, DUE TO THE POTENTIAL FOR
ROUNDS OF MODERATE TO HEAVY RAIN.
LITTLE HAS CHANGED WITH THE OVERALL PATTERN AND EXPECTATIONS FROM
EARLIER FORECASTS. THE DEEP LOW CENTERED OVER LA/MS EARLY MON IS
EXPECTED TO OPEN A BIT AND LIFT NNE INTO W TN/W KY THROUGH EARLY
TUE, AS THE TRAILING NEGATIVELY TILTED MID LEVEL TROUGH AND SURFACE
FRONT LIFT NE THROUGH GA AND THE WESTERN CAROLINAS. THE COMBINATION
OF DEEP AND PLENTIFUL MOISTURE AND ROUNDS OF FORCING FOR ASCENT
CONTINUE TO FAVOR A RISK FOR AREAS OF HEAVY RAIN TOTALS. THESE
INGREDIENTS INCLUDE A PLUME OF 1.5-1.8" PWS (~160% OF NORMAL) THAT
WILL SPREAD NORTHWARD ON THE E SIDE OF THE LOW THROUGH CENTRAL NC
STARTING LATE TONIGHT, SHIFTING INTO E NC LATE MON NIGHT, WITHIN A
LONG LOW-LEVEL SE FETCH OF ATLANTIC MOISTURE ON THE SW SIDE OF THE
EXITING HIGH, AND WITH CONTRIBUTIONS FROM GULF-SOURCE MOISTURE IN
MORE SOUTHERLY FLOW JUST ALOFT. WARM RAIN PROCESSES ARE FAVORED,
WITH PROJECTED LCL-0C DEPTH OF 11K-12K FT AMIDST A STREAM OF
ELEVATED INTEGRATED VAPOR TRANSPORT. WHILE IT WON'T BE RAINING
HEAVILY ALL OF THIS TIME, THERE MAY BE AT LEAST TWO MAIN WINDOWS OF
GREATER POTENTIAL WHERE FORCING WILL BE FOCUSED, INCLUDING EARLY MON
MORNING DUE TO A SURGE IN DEEP MOIST ISENTROPIC UPGLIDE, AND MON
EVENING/NIGHT DUE TO AN INCREASE IN UPPER DIVERGENCE IN THE EXIT
REGION OF THE SOUTHERLY UPPER JET. FORECAST TOTAL RAINFALL FROM
TODAY THROUGH MON NIGHT HAS ACTUALLY RISEN A BIT SINCE YESTERDAY,
WHICH COULD BE A RESPONSE TO DATA ASSIMILATION OF CURRENT RAINFALL
TO OUR S AND/OR INCLUSION OF RAINFALL FROM CONVECTION-ALLOWING
MODELS, AS WE'RE STARTING TO GET WITHIN THEIR TIME FRAME. THE LATEST
WPC SUPERENSEMBLE QPF PLUMES ARE OVERALL AROUND 1/2 INCH HIGHER WITH
TOTAL QPF THAN YESTERDAY'S OUTPUT. WE'RE MOST LIKELY TO SEE 2-4
INCHES OF RAIN THROUGH EARLY TUE, ALTHOUGH THE LATEST ENSEMBLE
PROBABILITIES GIVE A 10% CHANCE OF UP TO 5 INCHES IN SPOTS. THIS
COULD PRODUCE LOCALIZED FLOODING, ESP IN URBAN AREAS, WITH RISES ON
CREEKS AND STREAMS POSSIBLE, ALL SUPPORTING THE FLASH FLOOD WATCH
ISSUANCE. WITH ABUNDANT THICK CLOUDS AND MINIMAL INSOLATION, EXPECT
A TIGHTER DIURNAL TEMP RANGE, WITH HIGHS IN THE UPPER 60S TO MID 70S
FOLLOWED BY LOWS IN THE 60S. -GIH
LONG TERM /TUESDAY THROUGH SATURDAY/
AS OF 410 AM SUNDAY...
* POCKETS OF HEAVY RAIN WILL REMAIN POSSIBLE INTO TUE, ALONG WITH A
FEW STRONG STORMS.
* HOT WEATHER IS EXPECTED LATE WEEK.
TUE-TUE NIGHT: THE SLOW-MOVING MID LEVEL LOW WILL CONTINUE TO OPEN
AS IT TRACKS E/NE INTO WV, WHILE ITS TRAILING TROUGH AND SURFACE
FRONT PUSH FURTHER ENE INTO THE CAROLINAS, NUDGING THE PLUME OF
GREATEST AND MOST ANOMALOUS PW INTO OUR NE CWA AND EVENTUALLY TO OUR
NE AND OFF THE MID ATLANTIC COAST. IF HEAVY AND/OR TRAINING
RAINBANDS PERSIST OVER OUR NE TUE MORNING, A SHORT-TERM EXTENSION OF
THE FLASH FLOOD WATCH MAY BE NEEDED. BUT OVERALL, WE SHOULD SEE A
DECREASE IN HEAVY RAIN CHANCES WITH LOWERING PW AND WANING DYNAMIC
FORCING FOR ASCENT WITH WEAKENING MID LEVEL FLOW WITHIN THE
APPROACHING INCREASINGLY BAGGY TROUGH. PWS WILL STILL BE ABOVE
NORMAL, THOUGH, AND MODELS PROJECT MODERATE CAPE OF 1000-2000 J/KG
IN THE AFTERNOON WITH 25-35 KT OF DEEP LAYER BULK SHEAR AMIDST
DECENT LOW AND MID LEVEL LAPSE RATES, SO WILL MAINTAIN HIGH POPS,
MAINLY NE EARLY AND AREAWIDE LATE IN THE DAY, TAPERING DOWN TUE
EVENING/NIGHT. EXPECT HIGHS IN THE MID 70S TO NEAR 80, ALTHOUGH IF
CLOUD COVER IS MORE EXTENSIVE THAN EXPECTED, THESE HIGHS MAY BE
OPTIMISTIC. LOWS IN THE UPPER 50S TO LOW 60S.
WED-SAT: RAIN CHANCES WILL REMAIN HIGH ESP ACROSS OUR N AND E WED,
AS THE NEGATIVELY TILTED TROUGH LIFTS UP THROUGH THE AREA, ALTHOUGH
THE STEADY DECLINE IN MID LEVEL WIND SPEEDS WILL RESULT IN WANING
DPVA OVERALL. HIGH TEMPS WILL REMAIN SOMEWHAT REDUCED BY CLOUDS AND
SHOWERS, DESPITE SLOWLY REBOUNDING THICKNESSES, SO EXPECT HIGHS IN
THE UPPER 70S TO LOW 80S. BY THU, A DEEP LOW TRACKING THROUGH THE
ROCKIES AND DAKOTAS INTO THE UPPER MIDWEST WILL FORCE DOWNSTREAM
RIDGING TO BUILD INTO THE CAROLINAS FROM THE WSW, AND AS WE GET INTO
THE WARM SECTOR, OUR THICKNESSES WILL RISE TO 10 M ABOVE NORMAL THU.
BY FRI/SAT, AS THIS LOW SHEARS W-E AND SHIFTS SLOWLY E/ESE OVER S
ONTARIO, IT WILL TAMP DOWN THE RIDGE RESULTING IN A FAST W TO WNW
STEERING FLOW OVER THE E-CENTRAL CONUS, WITH A SHARPENING W-E
SURFACE FRONTAL ZONE TO OUR N FROM THE MID MISS VALLEY ACROSS THE
MID ATLANTIC. SUCH A PATTERN FAVORS THE POTENTIAL FOR MIDWEST MCS
ACTIVITY (OR ITS RESIDUAL CLOUDS AND MCV) TO PASS THROUGH OUR
REGION, SO WILL NEED TO MONITOR FOR THIS POSSIBILITY AS WE GET LATER
IN THE WEEK. AND PRIOR TO THIS, THE GFS PROJECTS HIGH CAPE OF 2000-
3000 J/KG AND 35-40 KT OF MID LEVEL FLOW, WHICH COULD SUPPORT
ORGANIZED STRONG LATE-DAY STORMS. FOR NOW, WILL CARRY LOW END
DIURNAL-LEANING POPS THU AND FRI, THEN A BIT HIGHER (NEAR CLIMO) FOR
SAT. WITH THICKNESSES 25 M ABOVE NORMAL FRI/SAT AND SURFACE
DEWPOINTS RISING TO NEAR OR OVER 70F, THE RESULTANT HEAT MAY BE A
HEALTH CONCERN, WITH THE EXPERIMENTAL HEAT RISK VALUES SUGGESTING AN
ELEVATED HEAT ILLNESS THREAT, AS HEAT INDICES MAY REACH 95-100F, ESP
FRI. EXPECT HIGHS IN THE 80S THU, UPPER 80S TO MID 90S FRI, AND MID
80S TO LOW 90S SAT WITH THE POTENTIAL FOR MORE CLOUDS AND BETTER
CONVECTION CHANCES. -GIH
AVIATION /06Z SUNDAY THROUGH THURSDAY/
AS OF 250 AM SUNDAY...
THROUGH 06Z MONDAY: MVFR CONDITIONS ARE GRADUALLY LIFTING NORTHWARD
TOWARD CENTRAL NC FROM THE SOUTH AND WILL EXIST OFF-AND-ON
THROUGHOUT THE DAYTIME TODAY MAINLY FROM RDU SOUTH AND WESTWARD.
WITH THE EXCEPTION OF KRWI, FLT CONDITIONS MAY DROP TO LOW-MVFR OR
IFR AT TIMES AS A BAND OF RAIN, CURRENTLY SEEN ON RADAR LIFTING
NORTH ACROSS SC, MAKES ITS WAY UP TO CENTRAL NC DURING THE MORNING
AND AFTERNOON HOURS. CIGS ARE THEN EXPECTED TO DROP TO IFR CRITERIA
AFTER SUNSET AND REMAIN THROUGH THE REST OF THE NIGHT.
AFTER 06Z MONDAY: WIDESPREAD MODERATE TO HEAVY RAIN AND IFR
CONDITIONS ARE FORECAST MONDAY THROUGH TUESDAY MORNING. SCATTERED TO
NUMEROUS SHOWERS/STORMS WILL REMAIN POSSIBLE EACH AFTERNOON THROUGH
AT LEAST WEDNESDAY WITH THE THREAT FOR OVERNIGHT SUB-VFR FOG/STRATUS
THROUGH WEDNESDAY NIGHT.
RAH WATCHES/WARNINGS/ADVISORIES
FLOOD WATCH FROM LATE TONIGHT THROUGH TUESDAY MORNING FOR
NCZ007>011-021>028-038>043-073>078-083>086-088-089.
SYNOPSIS...HARTFIELD
NEAR TERM...NP
SHORT TERM...HARTFIELD
LONG TERM...HARTFIELD
AVIATION...NP
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page