837
FXUS62 KRAH 231849
AFDRAH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
250 PM EDT WED APR 23 2025
SYNOPSIS
A BACKDOOR COLD FRONT WILL PUSH SLOWLY SOUTHWARD THROUGH THE AREA
THROUGH TONIGHT. THE 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 250 PM WEDNESDAY...
ISOLATED TO SCATTERED SHOWERS AND STORMS REMAIN POSSIBLE ACROSS
SOUTHERN AREAS THROUGH TONIGHT. BASED ON OBSERVED SURFACE DEWPOINTS
AND THETA-E, THE FRONTAL ZONE CURRENTLY STRETCHES ROUGHLY SW-NE
THROUGH CENTRAL NC, WITH DEWPOINTS IN THE 40S TO LOWER 50S TO ITS NW
AND MID 50S TO LOWER 60S TO ITS SE. THIS FRONTAL ZONE IS EXPECTED TO
SINK VERY SLOWLY TO THE S THEN STALL WHILE PIVOTING CLOCKWISE, AS
THE WEAK HIGH CENTERED TO OUR N TRACKS E OVER AND OFF THE MID
ATLANTIC COAST. WHILE THE LATEST RAP-BASED EFFECTIVE BULK SHEAR OVER
OUR AREA IS LOW, AT JUST 15-20 KTS ACROSS THE FAR SE CWA AND LOWER
TO THE N AND W, AREAS FROM THE TRIANGLE TO THE S AND E ARE WITHIN
500-1500 J/KG OF SBCAPE, WITH PWS OF 1-1.25", WHICH IS ABOUT 125-
150% OF NORMAL. SO DESPITE THE PRESENCE OF WEAK MLCINH AND POOR DEEP-
LAYER SHEAR, POPS WILL REMAIN WARRANTED ACROSS OUR FAR S AND SE
THROUGH THE EVENING, BEFORE GRADUALLY SHIFTING WESTWARD INTO OUR SW
OVERNIGHT AS DEEPENING LOW LEVEL ESE/SE FLOW RESULTS IN TERRAIN
UPGLIDE AND A POOLING OF BETTER MOISTURE OVER THE S PIEDMONT. PRECIP
SHOULD BE MORE CONVECTIVE IN NATURE THROUGH EARLY EVENING, WITH SLOW
STORM MOTION AND POSSIBLE BACK-BUILDING LEADING TO ISOLATED POCKETS
OF HIGH RAINFALL TOTALS. WE SHOULD THEN SEE MORE ISENTROPIC-LIFT-
DRIVEN PRECIP TONIGHT IN OUR SW AND FAR W, WHERE LOW BKN-OVC CLOUDS
ARE APT TO DEVELOP LATE NEAR AND S OF THE FRONTAL ZONE WITHIN AN
AREA OF LOW DEWPOINT DEPRESSIONS AND HIGH 100 M MIXING RATIO. AFTER
HIGHS IN THE UPPER 70S TO LOW 80S, EXPECT ABOVE-NORMAL LOWS IN THE
MID 50S TO LOW 60S EXCEPT 50-55 IN THE NE, IN THE AXIS OF THE
OUTGOING SURFACE RIDGE. -GIH
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 /SATURDAY THROUGH TUESDAY/
AS OF 300 AM WEDNESDAY...
- DAILY RAIN CHANCES CONTINUE THROUGH SATURDAY.
- TEMPERATURES REMAIN ABOVE-NORMAL THROUGH SATURDAY WITH A BRIEF
STINT OF COOLER, BELOW NORMAL TEMPS THE SECOND HALF OF THE WEEKEND/
EARLY NEXT WEEK.
SANDWICHED BETWEEN HIGH PRESSURE OVER THE WESTERN ATLANTIC AND AN
EASTWARD ADVANCING COLD FRONT INTO THE MS VALLEY, DAYTIME HEATING
AND WEAK DESTABLIZATION WITHIN THE CONTINUED MOIST AIRMASS WILL
SUPPORT ANOTHER AFTERNOON OF ISOLATED TO WIDELY SCATTERED
CONVECTION. THE ARRIVAL OF A COLD FRONT INTO THE AREA SATURDAY
AFTERNOON AND EVENING SHOULD YIELD MORE WIDESPREAD SHOWERS AND
STORMS, AND PERHAPS A LOW-END SEVERE THREAT AS BELT OF ENHANCED
SHEAR OF 25-30 KTS CLIPS NORTHERN PORTIONS OF THE FORECAST AREA.
SATURDAY LOOKS TO BE THE WARMEST OF THE TWO DAYS, WITH HIGHS
EXPECTED TO TOP OUT IN THE LOWER TO MID 80S.
SURFACE HIGH PRESSURE BUILDING SOUTH OUT OF CANADA WILL BRING A
BRIEF STINT OF BELOW NORMAL TEMPS AND NOTICEABLY DRIER/LESS HUMID
AIR SUNDAY-MONDAY, FOLLOWED BY A RETURN OF ABOVE NORMAL TEMPS BY
NEXT TUESDAY.
AVIATION /18Z WEDNESDAY THROUGH MONDAY/
AS OF 1255 PM WEDNESDAY...
VFR CONDITIONS SHOULD DOMINATE CENTRAL NC THROUGH THIS EVENING, WITH
A FEW ISOLATED EXCEPTIONS. AREAS OF MVFR CLOUDS WILL PERSIST IN THE
NC COASTAL PLAIN (NEAR RWI) UNTIL 20Z. AND SCATTERED SHOWERS ACROSS
FAR SOUTHERN PORTIONS OF CENTRAL NC WILL BRING PERIODS OF LIGHT RAIN
TO FAY THROUGH 21Z, ALTHOUGH SUB-VFR CONDITIONS WITH THESE SHOWERS
ARE UNLIKELY. AN ISOLATED STORM CAN'T BE RULED OUT NEAR FAY LATE,
BUT THE COVERAGE AND POTENTIAL DEVELOPMENT APPEARS TOO LOW AT THIS
TIME TO INCLUDE IN THE TAF. OTHERWISE, A MIX OF MID AND HIGH CLOUDS
WILL PREVAIL, WITH AREAS OF VFR CUMULUS CLOUDS. LATER TONIGHT, AFTER
04Z, IN ADDITION TO SCT-BKN MID CLOUDS, AREAS OF MVFR CIGS WILL
SPREAD IN, FIRST INTO THE SE (FAY) THEN SPREADING WNW THROUGH THE S
AND W PIEDMONT THROUGH THE NIGHT WHILE LIKELY DROPPING TO IFR. FAY
AS THE HIGHEST CHANCE OF MVFR-TO-IFR CIGS STARTING AFTER 04Z,
FOLLOWED BY A HIGH CHANCE AT INT/GSO AFTER 08Z. RDU MAY ALSO SEE SCT-
BKN MVFR AND PERHAPS BRIEFLY IFR CLOUDS, BUT CONFIDENCE IS LOWER
HERE. RWI SHOULD STAY LARGELY VFR OVERNIGHT, ALTHOUGH SCT MVFR
CLOUDS ARE POSSIBLE 04Z-11Z. WHILE SKIES WILL IMPROVE ELSEWHERE BY
13Z, ADVERSE AVIATION CONDITIONS SHOULD LINGER THROUGH MUCH OF THU
MORNING AT INT/GSO, ESPECIALLY INT, ALTHOUGH CIGS WILL SLOWLY RISE
THROUGH THE MVFR CATEGORY. SURFACE WINDS WILL BE LIGHT AND VARIABLE
OR MOSTLY FROM THE NE OR ENE UNDER 10 KTS.
LOOKING BEYOND 18Z THU: EXPECT MOSTLY VFR CONDITIONS THU AFTERNOON,
ALTHOUGH SCATTERED SHOWERS AND PERHAPS A LATE-DAY STORM MAY OCCUR,
MAINLY AT FAY. SUB-VFR CONDITIONS ARE EXPECTED TO DEVELOP ONCE AGAIN
THU NIGHT AFTER 04Z, LASTING THROUGH FRI MORNING, WITH THE HIGHEST
CHANCE AT INT/GSO, WHERE LIGHT RAIN IS POSSIBLE, AND A LOWER CHANCE
AT RDU/FAY. SHOWERS AND STORMS MAY OCCUR FRI AFTERNOON THROUGH SAT,
AHEAD OF AND ALONG A COLD FRONT THAT WILL CROSS CENTRAL NC SAT.
DRY/VFR CONDITIONS ARE EXPECTED SUN-MON UNDER HIGH PRESSURE. -GIH
RAH WATCHES/WARNINGS/ADVISORIES
NONE.
SYNOPSIS...HARTFIELD
NEAR TERM...HARTFIELD
SHORT TERM...SWIGGETT
LONG TERM...CBL
AVIATION...HARTFIELD
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