476
FXUS62 KRAH 240520
AFDRAH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
120 AM EDT THU APR 24 2025
SYNOPSIS
A BACKDOOR COLD FRONT WILL STALL ACROSS THE CAROLINAS AND WEAKEN
THROUGH THURSDAY, AS HIGH PRESSURE TO OUR NORTH MOVES OVER THE MID
ATLANTIC REGION THEN OFFSHORE. THE FRONT WILL DISSIPATE FRIDAY,
PUTTING US BACK IN A WARM AND HUMID SOUTHERLY FLOW AHEAD OF A COLD
FRONT THAT WILL APPROACH FROM THE WEST FRIDAY NIGHT INTO SATURDAY.
NEAR TERM /THROUGH TONIGHT/
AS OF 904 PM WEDNESDAY...
THE CONVECTION THAT WAS LOCATED OVER THE CENTRAL AND SOUTHERN
COASTAL PLAIN AND PARTS OF JOHNSTON COUNTY HAS LARGELY DISSIPATED IN
THE LAST HOUR OR SO. MUCH OF THIS CONVECTION DEVELOPED WITH A
WESTWARD MOVING OUTFLOW BOUNDARY FROM STORMS CLOSER TO THE NC COAST.
THE SURFACE FRONT, MEANWHILE, IS LOOSELY DEFINED, BUT MAINLY SOUTH
OF CENTRAL NC. IT SHOULD CONTINUE TO PROGRESS SOUTH AND WEST,
STALLING TO OUR SOUTHWEST OVERNIGHT. MUCH OF THE CONVECTION OVER THE
COASTAL PLAIN HAS STABILIZED THE ATMOSPHERE THERE. BASED ON SOME
GUIDANCE BUT MORE HEAVILY RELYING ON OBSERVATIONAL TRENDS, STILL
THINK ISOLATED SHOWERS OR STORMS WILL DEVELOP INTO THE LATE EVENING,
MAINLY FOR AREAS OVER THE SOUTHERN PIEDMONT, SANDHILLS, AND POINTS
SOUTHWEST OF THE TRIANGLE. THERE ARE SIGNS OF THIS ALREADY WITH
SATELLITE SHOWING CLOUDS NEAR 6 KFT TO THE SOUTHWEST OF RALEIGH.
THIS REGION HAS NOT BEEN WORKED OVER FROM EARLIER CONVECTION AND MAY
FEED ON SOME 500 TO 1000 J/KG OF INSTABILITY, ALONG WITH FORCING
FROM THE WESTWARD MOVING OUTFLOW. ADDITIONAL ISOLATED CONVECTION MAY
DEVELOP OVERNIGHT OVER THE WESTERN/SOUTHERN PIEDMONT DUE TO
SOUTHEASTERLY POOLING OF MOISTURE AND UPSLOPE FLOW WITH THE 925-850
MB FLOW SOUTHEASTERLY. OTHERWISE, EXPECT FAIRY DRY CONDITIONS
OVERNIGHT. THE POOLING OF MOISTURE WILL FAVOR A GOOD CHANCE OF LOW
STRATUS DEVELOPING OVER THE WESTERN PIEDMONT AND TRIAD, THOUGH FOG
APPEARS MINIMAL THUS FAR WITH LOW TEMPERATURES TEMPERED BY CLOUDS IN
THE UPPER 50S TO LOW 60S IN THIS AREA. LOWS SHOULD BE COOLER AND
MORE SEASONAL IN OUR NORTHEAST ZONES, WHERE CLOUDS WILL BE LESS
PREVALENT, WITH UPPER 40S TO LOW 50S.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/
AS OF 200 PM WEDNESDAY...
* SEASONABLY MILD WITH SHOWERS AND ISOLATED STORMS POSSIBLE DURING
THE AFTERNOON AND EARLY EVENING.
UNDER WEAKLY SOUTHWESTERLY AND SUBTLY PERTURBED FLOW ALOFT, SURFACE
HIGH PRESSURE WILL SLOWLY SHIFT OFFSHORE WHILE AN AREA OF LOW
PRESSURE TRACKS FROM THE MID-MS VALLEY INTO THE GREAT LAKES REGION
BY FRI NIGHT. A QUASI-STATIONARY FRONT WILL BUCKLE NORTHWARD ACROSS
WESTERN NC THURS WITH A WARM SECTOR CHARACTERIZED BY DEW POINTS IN
THE UPPER 50S TO LOW 60S. DIURNAL HEATING SHOULD RESULT IN 500-1000
SBCAPE TO DEVELOP IN THE WESTERN SANDHILLS AND WESTERN PIEDMONT
WHERE SOME SHOWERS/STORMS WILL BE POSSIBLE. WEAK SHEAR (<20KTS) WILL
RESULT IN MOSTLY PULSE STORM MODE AND LITTLE STORM ORGANIZATION IS
EXPECTED. ANOTHER AREA OF SHOWERS WILL BE POSSIBLE THURS NIGHT AS A
CONVECTIVELY ENHANCED VORTMAX, CURRENTLY OVER THE LOWER MS VALLEY,
WILL SHIFT INTO WESTERN PIEDMONT OF NC AND SOUTHERN APPALACHIANS.
THERE IS SOME WEAK ELEVATED INSTABILITY SO SOME ISOLATED STORMS
CAN'T BE RULED OUT. HIGHS MID 70S TO LOW 80S. LOWS IN THE LOW 50S TO
LOW 60S.
THE SURFACE FRONT WILL BECOME MORE WASHED OUT FRI AS THE SURFACE
HIGH SLIPS FARTHER OFFSHORE AND UNIFORMLY SOUTHERLY FLOW RETURNS TO
THE AREA. CONTINUED, WARM, MOIST AIRMASS IN PLACE SHOULD RESULT IN
ANOTHER DAY OF DIURNALLY DRIVEN SHOWERS/STORMS. HIGHS MID 70S TO LOW
80S. LOWS LOW/MID 60S.
LONG TERM /FRIDAY THROUGH WEDNESDAY
AS OF 300 PM WEDNESDAY...
-SHOWER AND STORMS POSSIBLE SATURDAY, THEN DRY THROUGH WEDNESDAY.
- TEMPERATURES WILL BE ABOVE-NORMAL SATURDAY WITH A BRIEF COOL DOWN
FOR SUNDAY AND MONDAY THEN ABOVE NORMAL AGAIN FOR MID TO LATE WEEK.
A COLD FRONT WILL BE MOVING INTO THE MID-ATLANTIC REGION EARLY
SATURDAY BRINGING INCREASED RAIN CHANCES THROUGH SATURDAY EVENING.
THE BEST CHANCE FOR STORMS WILL BE IN THE AFTERNOON AND EVENING
HOURS. SOME MODEL DATA IS SUGGESTING A LOW END THREAT FOR ISOLATED
SEVERE STORMS TO DEVELOP AS CAPE VALUES RANGE FROM 600-1200 J/KG AS
THE FRONT SWINGS ACROSS THE REGION. WHILE WE ARE NOT IN ANY SORT OF
SPC OUTLOOK FOR SEVERE WEATHER CURRENTLY, I WOULD EXPECT AT LEAST A
MARGINAL RISK FOR SEVERE WEATHER OVER PORTIONS OF THE AREA ON
SATURDAY. AS THE FRONTAL BOUNDARY EXITS THE REGION LATE SATURDAY
NIGHT EARLY SUNDAY, DRY SURFACE HIGH WILL SLOWLY MOVE INTO THE
REGION WITH COOLER TEMPERATURES AND REFRESHING DEW POINTS IN THE
40S. TEMPERATURES WILL BE IN THE 70S ON SUNDAY AND MONDAY AND 80S ON
TUESDAY AND WEDNESDAY. WEDNESDAY IS EXPECTED TO BE THE WARMEST DAY
OF THE 7-DAY FORECAST WITH WAA ACROSS THE REGION AHEAD OF THE NEXT
FRONTAL SYSTEM. EXPECT TEMPS IN THE MID TO UPPER 80S WITH A FEW
WARMER SPOTS POSSIBLY HITTING 90 DEGREES. DEPENDING ON THE TIMING OF
THE FRONT, AFTERNOON SHOWERS COULD BE POSSIBLE WEDNESDAY AFTERNOON.
AVIATION /06Z THURSDAY THROUGH MONDAY/
AS OF 120 AM THURSDAY...
A WEAK COLD FRONT WILL CONTINUE TO DRIFT SOUTH THROUGH THE AREA AND
IS FORECAST STALL OUT ACROSS SC LATER THIS MORNING. HIGH PRESSURE
BUILDING INTO THE AREA FROM THE NE WILL ADVECT SLIGHTLY DRIER LOW-
LEVEL AIR INTO NORTHERN COASTAL PLAIN AND CENTRAL PIEDMONT. THIS
DRIER AIR SHOULD BE SUFFICIENT TO INHIBIT ANY SUB-VFR RESTRICTIONS
AT KRWI AND KRDU. HOWEVER, AT KFAY, KGSO AND KINT, A MOIST SELY LOW-
LEVEL FLOW WILL ADVECT MVFR/IFR CEILINGS FIRST AT KFAY ~06Z AND THEN
INT/GSO ~ 08Z, POTENTIALLY LOWERING TO LIFR BRIEFLY AROUND DAYBREAK.
THE SUB-VFR CEILINGS AT KFAY SHOULD LIFT AND SCOUR OUT BETWEEN BY
MID MORNING. IT WILL TAKE A LITTLE LONGER FOR THE RETURN OF VFR
CONDITIONS AT KINT AND KGSO, LIFTING BETWEEN 16 TO 18Z.
A MOIST SELY UPSLOPE FLOW ON THE PERIPHERY OF THE SFC HIGH WILL
PROMOTE THE DEVELOPMENT OF SCATTERED SHOWERS AND POSSIBLY A FEW
STORM MAINLY ACROSS THE WESTERN TERMINALS(KINT AND KGSO) DURING THE
AFTERNOON AND EVENING.
LOOKING BEYOND 06Z/FRIDAY: SUB-VFR CONDITIONS ARE EXPECTED TO
DEVELOP ONCE AGAIN THURSDAY NIGHT AFTER 04Z, LASTING THROUGH FRI
MORNING, WITH THE HIGHEST CHANCE AT INT/GSO, WHERE SHOWERS ARE
POSSIBLE, AND A LOWER CHANCE AT RDU/FAY. SCATTERED SHOWERS AND
STORMS MAY OCCUR FRIDAY AFTERNOON THROUGH SATURDAY, AHEAD OF AND
ALONG A COLD FRONT THAT WILL CROSS CENTRAL NC SAT. DRY/VFR
CONDITIONS ARE EXPECTED SUNDAY AND MONDAY UNDER HIGH PRESSURE.
RAH WATCHES/WARNINGS/ADVISORIES
NONE.
SYNOPSIS...HARTFIELD
NEAR TERM...KREN
SHORT TERM...SWIGGETT
LONG TERM...CA
AVIATION...CBL/HARTFIELD
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