886
FXUS62 KRAH 120210
AFDRAH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
1010 PM EDT SUN MAY 11 2025
SYNOPSIS
A SLOW MOVING UPPER LOW CENTERED OVER THE LOWER MISSISSIPPI
RIVER VALLEY WILL DRIFT NORTHEAST THROUGH THE MID SOUTH TO THE
CENTRAL APPALACHIANS THROUGH WEDNESDAY, BRINGING WET AND UNSETTLED
WEATHER TO THE REGION.
NEAR TERM /THROUGH TONIGHT/
AS OF 1010 PM SUNDAY...
* FLOOD WATCH FOR ALL OF CENTRAL NC IN EFFECT FROM 2 AM MONDAY
THROUGH 12Z TUESDAY.
THE 00Z UPPER AIR ANALYSES SHOW THE NEARLY VERTICALLY STACKED LOW
OVER LA, WITH A SE TO NW ORIENTED RIDGE OVER CENTRAL NC FROM HIGH
PRESSURE OVER THE CARIBBEAN. CENTRAL NC AT BOTH H7 AND H85 ARE
SATURATED, OR NEARLY SO, WHILE THE H25 JET EXIT REGION REMAINS TO
THE SOUTHWEST OVER THE SOUTHEAST US. AT THE SURFACE, CENTRAL NC
RELATIVELY HIGH PRESSURE REMAINS OVER THE AREA, BETWEEN A FRONTAL
ZONE TO BOTH THE NORTH AND SOUTH. THE SURFACE LOW WAS ANALYZED OVER
SW MS AS OF 00Z. THE LOW AT BOTH THE SURFACE AND ALOFT SHOULD REMAIN
FAIRLY STATIONARY OVERNIGHT, THE BEGIN LIFTING NWD (SFC)/NEWD
(ALOFT) AROUND DAYBREAK MONDAY. THE CURRENT LULL IN PRECIPITATION
BETWEEN MID-LEVEL DISTURBANCES WILL BE RELATIVELY SHORT LIVED, AS
THE NEXT PAIR OF DISTURBANCES LIFT NNEWD ACROSS THE REGION TONIGHT,
BEGINNING IN THE NEXT COUPLE/FEW HOURS. WHILE RAIN, WITH EMBEDDED
SHOWERS/ISO THUNDER, WILL LIKELY BEGIN TO SPREAD INTO THE AREA IN
THE NEXT FEW HOURS, ONSET OF THE MORE WIDESPREAD VIGOROUS CONVECTION
WITH MODERATE TO HEAVY RAINFALL SHOULD BE BETWEEN 3AM AND 6AM MONDAY
OVER THE SRN AND WRN PIEDMONT, THEN SPREAD EWD THEREAFTER. AHEAD OF
THE RAIN, THE 00Z HRRR IS SHOWING SOME POTENTIAL FOG DEVELOPMENT IN
THE NEXT COUPLE OF HOURS, SPREADING ACROSS MUCH OF THE PIEDMONT THEN
LIFTING NWWD THROUGH 12Z MON. AS OF 02Z, SOME OBSERVATIONS ARE
SHOWING VSBYS AROUND 5SM, SO WILL SEE HOW THAT TRENDS IN THE NEXT
HOUR OR SO. EXPECT SOMEWHAT STEADY TEMPERATURES OVERNIGHT, WITH LOWS
RANGING FROM UPPER 50S NE TO MID 60S SE.
SHORT TERM /MONDAY AND MONDAY NIGHT/
AS OF 245 PM SUNDAY...
FLOOD WATCH CONTINUES FOR ALL OF CENTRAL NC THROUGH DAYBREAK
TUESDAY, DUE TO THE POTENTIAL FOR ROUNDS OF HEAVY RAIN.
AS THE UPPER LOW SHIFTS LOWLY INTO THE TN VALLEY MONDAY AND MONDAY
NIGHT, A DEEP PLUME OF MOISTURE WITH PRECIPITABLE WATER VALUES OF
1.5 TO 2 INCHES WILL BE PULLED NORTHWARD OVER THE REGION. THERE WILL
BE A WARM FRONT THAT WILL PUSH INTO CENTRAL NC, BUT WITH SOME IN-
SITU CAD OVER THE PIEDMONT LIKELY MONDAY INTO MONDAY EVENING. THIS
WILL LEAVE A BOUNDARY MOST LIKELY OVER THE PIEDMONT, WITH THE MOST
UNSTABLE AIR OVER THE COAST INTO THE COASTAL PLAIN. THIS IS WHERE
THE HEAVIEST QPF WILL LIKELY BE, WITH ANOTHER MAXIMUM SOMEWHERE NEAR
THE CAD BOUNDARY OVER THE PIEDMONT. THE LATEST HI-RES MODELS SUGGEST
MULTIPLE BANDS OF SHOWERS AND ISOLATED THUNDERSTORMS WITH HEAVY TO
VERY HEAVY RAINFALL RATES OR SHORT BURSTS OF HEAVY RAINFALL. WITH
SOME TRAINING OF THE HEAVIEST RAIN LIKELY, FLASH FLOOD HOURLY RATES
MAY BE EXCEEDED ESPECIALLY IN URBAN AREAS. UP TO 2 INCHES OF RAIN IN
AN HOUR WILL BE POSSIBLE, ESPECIALLY OVER THE COASTAL PLAIN. IN
ADDITION, IT MAY TAKE A FEW BURSTS OF HEAVY RAINFALL TO SATURATE THE
SOILS IN SOME AREAS WITH FLOODING MORE LIKELY WITH EACH PASSING
PERIOD OF HEAVY RAINFALL.
RECENT RAIN HAS AIDED IN WETTING THE SOIL, THOUGH NO REGION IS
REALLY SATURATED AT THE MOMENT. THIS IS A POSITIVE. ANOTHER POSITIVE
IS THAT DROUGHT (D0 TO D2) CONDITIONS CONTINUE OVER MUCH OF CENTRAL
NC AND THIS RAINFALL WILL AID IN TEMPERING THAT.
EXPECT MULTIPLE BANDS OF HEAVY RAINFALL WITH A FEW THUNDERSTORMS
POSSIBLE MONDAY WITH HIGHS IN THE UPPER 60S NW-N RANGING INTO THE
MID 70S SOUTHEAST. SHOWERS AND A SOME THUNDER WILL CONTINUE IN BANDS
ACROSS THE REGION MONDAY NIGHT WITH THE CAMS POTENTIALLY INDICATING
A SUBTLE SHIFT TO THE EAST OF THE HEAVIEST RAINFALL RATES LATE. LOWS
WILL BE MOSTLY IN THE 60S. ALL SAID, STORM TOTALS THROUGH
12Z/TUESDAY SHOULD RANGE BETWEEN 2 TO LOCALLY 4 INCHES.
LONG TERM /TUESDAY THROUGH SUNDAY/
AS OF 415 PM SUNDAY...
THE CLOSED MID/UPPER LOW CENTERED OVER THE TN VALLEY WILL MOVE NE ON
TUESDAY, REACHING THE OH VALLEY AND CENTRAL APPALACHIANS ON TUESDAY
NIGHT AND OPENING UP INTO A WAVE. MEANWHILE THE OCCLUDED SURFACE LOW
WILL DRIFT EAST AND WEAKEN FURTHER, REACHING THE SOUTHERN
APPALACHIANS ON TUESDAY NIGHT. THERE WILL CONTINUE TO BE A DEEP
STREAM OF ATLANTIC MOISTURE AHEAD OF THE MID/UPPER LOW, BUT THE
GREATEST PW AXIS OF 1.5+" WILL MOSTLY SHIFT NE INTO CENTRAL AND
EASTERN VA BY THIS POINT AS THE LOW SHIFTS NE. HOWEVER, WITH MUCAPE
OF 1500 TO AS MUCH AS 2500 J/KG DEPICTED ON MODEL GUIDANCE, THERE
COULD STILL BE SOME POCKETS OF HEAVY RAIN RATES ACROSS CENTRAL NC,
PARTICULARLY OVER THE NE PIEDMONT AND NORTHERN COASTAL PLAIN. THUS
THE WPC HAS OUR REGION IN A LEVEL 1 OF 4 (MARGINAL) RISK FOR
EXCESSIVE RAINFALL ON TUESDAY. ADDITIONAL QPF ON TUESDAY/TUESDAY
NIGHT IS GENERALLY IN THE HALF INCH TO INCH RANGE ON AVERAGE ACROSS
THE NE, WITH LESSER AMOUNTS IN THE SOUTH AND WEST. LOCALLY HIGHER
AMOUNTS WILL BE POSSIBLE IN ANY STORMS, AND BY THIS POINT THE GROUND
SHOULD BE SATURATED ENOUGH THAT IT WON'T TAKE MUCH ADDITIONAL
RAINFALL TO CAUSE MORE FLOODING CONCERNS, AND THERE IS A CHANCE THE
FLOOD WATCH WILL HAVE TO BE EXTENDED BEYOND 12Z TUESDAY. MODELS HAVE
BEEN TRENDING FASTER WITH THE SYSTEM, AND IF THIS CONTINUES, THAT
WOULD LESSEN THESE CONCERNS. IT IS UNCLEAR WHETHER THERE WILL BE
ENOUGH SHEAR AVAILABLE FOR ORGANIZED CONVECTION, SO WHILE A FEW
STRONG STORMS WITH LOCALLY STRONG WINDS AND SMALL HAIL CAN'T BE
RULED OUT, SPC ONLY HAS AN AREA OF DAY 3 GENERAL THUNDER FOR NOW.
TUESDAY'S TEMPERATURES WILL BE KEPT DOWN BY THE WIDESPREAD CLOUDS
AND PRECIPITATION, WITH FORECAST HIGHS IN THE MID-TO-UPPER-70S.
SHOWER AND STORM CHANCES WILL LESSEN ON TUESDAY NIGHT, BUT WITH
WIDESPREAD CLOUD COVER, LOWS WILL STILL BE MILD, IN THE LOWER-TO-MID-
60S.
SHOWER COVERAGE WILL DECREASE SOMEWHAT ON WEDNESDAY AS THE LOW LIFTS
FURTHER NORTH, SO CAPPED POPS AT LIKELY, AGAIN HIGHEST IN THE NE.
AGAIN A FEW STORMS CAN'T BE RULED OUT WITH WEAK TO MODERATE
DESTABILIZATION, BUT NOT EXPECTING ANYTHING SEVERE AS THE MID-LEVEL
FLOW WILL BE EVEN MORE DIMINISHED BY THIS POINT. FORECAST HIGHS ARE
MID-70S TO LOWER-80S. DRIER AIR FROM NW FLOW ALOFT SHOULD REALLY
BEGIN TO MOVE IN ON WEDNESDAY NIGHT AS THE MID-LEVEL TROUGH FINALLY
PUSHES TO OUR EAST. LOWS SHOULD BE IN THE UPPER-50S TO MID-60S.
MID-LEVEL RIDGING WILL BUILD TO OUR WEST ON THURSDAY AND MOVE
OVERHEAD ON THURSDAY NIGHT, GETTING REPLACED BY FAST ZONAL FLOW
ACROSS CENTRAL NC ON FRIDAY AND SATURDAY AS THE RIDGE FLATTENS. THUS
WIDESPREAD UPPER FORCING WILL BE LACKING, AND WE WILL INSTEAD MOSTLY
RELY ON DAYTIME HEATING AND BOUNDARY LAYER DESTABILIZATION FOR
AFTERNOON/EVENING SHOWERS AND STORMS, ALONG WITH POSSIBLE MCS'S FROM
THE MIDWEST TRACKING NEAR OUR REGION. HOWEVER, THESE MCS'S ARE
IMPOSSIBLE TO PINPOINT WITH ANY SPECIFICITY THIS FAR OUT. SO POPS
ARE ONLY IN THE SLIGHT TO LOW CHANCE RANGE EACH DAY, INCREASING A
BIT TO CHANCE EVERYWHERE ON SATURDAY. MODERATE DESTABILIZATION WILL
BE POSSIBLE, PERHAPS EVEN STRONG (2000-3000+ J/KG OF CAPE) ON FRIDAY
ACCORDING TO LATEST GUIDANCE. SO A FEW STRONG TO SEVERE STORMS CAN'T
BE RULED OUT EACH DAY. TEMPERATURES WILL ALSO BE ON THE INCREASE,
WITH HIGHS IN THE MID-TO-UPPER-80S ON THURSDAY AND UPPER-80S TO MID-
90S ON FRIDAY, THEN DECREASING A BIT TO MID-80S TO LOWER-90S ON
SATURDAY WITH BETTER CONVECTION CHANCES. DEW POINTS WILL RISE TO THE
UPPER-60S AND POSSIBLY LOWER-70S ON FRIDAY AND SATURDAY, SO HEAT
INDICES WILL BE A CONCERN BOTH DAYS, ESPECIALLY ON FRIDAY WHEN THEY
COULD REACH THE MID-90S TO 100 IN THE SOUTH AND EAST. CONFIDENCE IN
THE OVERALL PATTERN IS QUITE LOW BY SUNDAY AS THE ECMWF AND MANY OF
ITS ENSEMBLES DRY US OUT BEHIND A COLD FRONT, WHILE THE GFS/GEFS AND
SLOWER WITH THE FRONT, THUS KEEPING US WARM AND WET. FOR NOW JUST
CONTINUE THE SLOW DECREASING TREND IN TEMPERATURES, WITH POPS IN THE
SLIGHT CHANCE RANGE.
AVIATION /00Z MONDAY THROUGH FRIDAY/
AS OF 755 PM SUNDAY...
THROUGH 00Z TUESDAY: LIGHT RAIN HAS BRIEFLY COME TO AN END ACROSS
CENTRAL NC, BUT WIDESPREAD TO NUMEROUS SHOWERS OVER SC WILL EXPAND
NORTHWARD THROUGH THE OVERNIGHT HOURS. EVEN IN THE ABSENCE OF
SHOWERS/STORMS, CONDITIONS WILL DETERIORATE THIS EVENING AND
OVERNIGHT AS IFR CIGS DEVELOP ALONG WITH SOME MVFR VSBYS. BEFORE
RAIN ARRIVES, SOME MODEL GUIDANCE IS HINTING AT PATCHY DENSE FOG
BRIEFLY DEVELOPING AS CIGS DROP TO AIRPORT MINIMUMS, BUT CONFIDENCE
ON TERMINAL RESTRICTIONS AT THE TAF SITES IS LOW. SEVERAL BANDS OF
SHOWERS AND ISOLATED THUNDERSTORMS WILL MOVE ACROSS THE REGION LATE
TONIGHT THROUGH MONDAY NIGHT WITH IFR TO LIFR CONDITIONS EXPECTED.
AFTER 00Z TUESDAY: BANDS OF MODERATE TO HEAVY RAIN AND IFR
CONDITIONS WILL MORE-OR-LESS CONTINUE THROUGH TUESDAY MORNING.
DIURNALLY DRIVEN SCATTERED SHOWERS AND THUNDERSTORMS WILL CONTINUE
TUESDAY AFTERNOON THROUGH LATE WEEK. LATE NIGHT LOW STRATUS (IFR TO
LIFR) WILL BE LIKELY.
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...BADGETT
NEAR TERM...KC
SHORT TERM...BADGETT
LONG TERM...DANCO
AVIATION...SWIGGETT/BADGETT
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