082
FXUS62 KRAH 311154
AFDRAH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
754 AM EDT MON MAR 31 2025
SYNOPSIS
ON THE WESTERN PERIPHERY OF HIGH PRESSURE CENTERED NEAR AND EAST OF
BERMUDA, A COLD FRONT WILL MOVE EAST AND ACROSS THE MIDDLE ATLANTIC
AND CAROLINAS THIS AFTERNOON THROUGH EARLY TONIGHT. COOL HIGH
PRESSURE WILL FOLLOW AND BUILD ACROSS THE REGION TUESDAY AND TUESDAY
NIGHT.
NEAR TERM /THROUGH TONIGHT/
AS OF 430 AM MONDAY...
* ENHANCED/LEVEL 3 OF 5 RISK FOR SEVERE STORMS THIS AFTERNOON
THROUGH EVENING
* UNSEASONABLY WARM AND HUMID THROUGH THIS EVENING, THEN TURNING
COOLER LATE TONIGHT-EARLY TUE MORNING
WITHIN A SEASONABLY STRONG BELT OF MID-LATITUDE WESTERLIES, A
SHORTWAVE PERTURBATION OVER THE SRN HIGH PLAINS THIS MORNING WILL
PIVOT EWD AND ACROSS THE MID-SOUTH TODAY AND THE MIDDLE ATLANTIC AND
CAROLINAS TONIGHT. PRECEDING THAT FEATURE, A BAND OF DEEP CONVECTION
AND ASSOCIATED CONVECTIVELY-AMPLIFIED VORTICITY STRETCHING ACROSS
THE TN AND LWR MS VALLEYS THIS MORNING WILL MOVE EWD AND ACROSS GA
AND THE WRN AND W-CNTL CAROLINAS THIS AFTERNOON AND THE E-CNTL AND
ERN CAROLINAS THIS EVENING. THE LATTER, CONVECTIVELY-AMPLIFIED
TROUGH --AND ASSOCIATED 40-45 KTS OF SWLY MID-LEVEL FLOW AND
SIMILARLY STRONG EFFECTIVE SHEAR-- WILL LIKELY BE MOST INFLUENTIAL
FOR FORCING FOR ASCENT AND THE MAINTENANCE AND ORGANIZATION OF DEEP
CONVECTION ACROSS CNTL NC DURING THE PERIOD.
AT THE SURFACE, A PRE/KATA-FRONTAL BAND OF CONVECTION AND OUTFLOW
WILL MOVE EAST INTO THE SRN AND WRN NC PIEDMONT DURING THE MID TO
LATE AFTERNOON, REACH THE COASTAL PLAIN THIS EVENING, AND PASS THE
OUTER BANKS AROUND MIDNIGHT. IT MAY BE ACCOMPANIED BY A MESOLOW AND
ASSOCIATED CONVERGENCE, LOCALLY-BACKED FLOW, AND UPR 60S SURFACE
DEWPOINTS ACROSS N-CNTL GA AND THE W-CNTL CAROLINAS THIS AFTERNOON,
THEN REACH NERN NC/SERN VA THIS EVENING. A SYNOPTIC COLD FRONT, AND
FOLLOWING SHARPLY DRIER CHARACTERIZED BY SURFACE DEWPOINTS FALLING
THROUGH THE 40S, WILL REACH THE SRN THROUGH NWRN NC PIEDMONT BEFORE
MIDNIGHT, THEN SPREAD EAST ACROSS THE REST OF CNTL NC OVERNIGHT.
DESPITE WIDESPREAD LOW OVERCAST THAT WILL BE IN PLACE ACROSS CNTL NC
THIS MORNING, TEMPERATURES AT THE ONSET OF DIURNAL HEATING WILL
ALREADY BE CLOSE TO THE CURRENT, MID 60S F VALUES. A COMBINATION OF
SSWLY FLOW AND WARM ADVECTION, AND GRADUAL LIFTING AND SCATTERING OF
THE LOW CLOUD LAYER, SHOULD ALLOW TEMPERATURES TO DIURNALLY WARM 10-
15 F AND INTO THE UPR 70S, TO LWR 80S WHERE BREAKS IN THE OVERCAST
SHOULD BE MOST PREVALENT OVER THE ERN SANDHILLS, NORTHEAST PIEDMONT,
AND COASTAL PLAIN. WHEN COMBINED WITH SEASONABLY RICH SURFACE
DEWPOINTS MOSTLY IN THE LWR-MID 60S, AND A MODIFIED EML AND LAYER OF
6.5 TO 7 C/KM MID-LEVEL LAPSE RATES, MODERATE DESTABILIZATION INTO
THE 1000-1500 J/KG RANGE SHOULD RESULT OVER CNTL NC.
THE GREATEST AND MOST-CONCENTRATED SEVERE RISK WILL LIKELY ACCOMPANY
THE STRONGEST EMBEDDED MCVS AND SURFACE MESOLOW, WHICH AT THIS TIME
APPEAR TO BE FAVORED IN A CORRIDOR FROM THE UPSTATE OF SC, NEWD
ACROSS THE SRN NC PIEDMONT AND WRN SANDHILLS LATE THIS AFTERNOON
INTO EARLY THIS EVENING, BEFORE THE AIRMASS BEGINS TO NOCTURNALLY-
COOL. THE AFOREMENTIONED BACKING OF THE SURFACE FLOW AHEAD OF THE
POSSIBLE MESOLOW WILL CAUSE OTHERWISE MODEST LOW-LEVEL SHEAR TO
INCREASE AND HODOGRAPHS IN THE LOWEST FEW KILOMETERS TO LENGTHEN AND
CLOCKWISE-CURVE. ALL HAZARDS, INCLUDING THE GREATEST RELATIVE
TORNADO RISK, WILL EXIST THERE. OTHERWISE AND ELSEWHERE, WEAKER
SHEAR IN THE LOW-LEVELS, BUT BENEATH STRONGER SWLY FLOW ABOVE AND
WITH ELONGATED AND RELATIVELY-STRAIGHT HODOGRAPHS THROUGH THE
MID/UPR-LEVELS, WILL FAVOR STORM ORGANIZATION AND POSSIBLE SPLITTING
CELLS, WITH A RISK OF LARGE HAIL AND DAMAGING WIND GUSTS.
ADDITIONAL, GENERALLY SHALLOWER/WEAKER AND LESS ORGANIZED CELLS MAY
REDEVELOP ALONG THE ADVANCING SYNOPTIC FRONT EARLY TONIGHT, WITH THE
GREATEST COVERAGE ACROSS THE NRN PIEDMONT AND NRN AND CNTL COASTAL
PLAIN. LOW TEMPERATURES, STILL 6-12 F ABOVE AVERAGE, SHOULD REACH
THE UPR 40S OVER THE NRN PIEDMONT TO LOW-MID 50S ELSEWHERE, AS
CLEARING SKIES AND COOLER AND DRIER POST-FRONTAL AIR OVERSPREAD THE
AREA OVERNIGHT.
SHORT TERM /TUESDAY AND TUESDAY NIGHT/
AS OF 345 AM MONDAY...
DRY WESTERLY FLOW AND SUBSIDENCE ALOFT BEHIND THE DEPARTING
SHORTWAVE WILL PROMOTE MOSTLY SUNNY SKIES ACROSS CENTRAL NC ON
TUESDAY. AT THE SURFACE, LOW PRESSURE WILL PUSH NE OF THE CANADIAN
MARITIMES AND GET REPLACED BY CANADIAN HIGH PRESSURE RIDGING DOWN
FROM ONTARIO INTO THE US MID-ATLANTIC. THIS WILL BRING NORTHERLY
FLOW AND ONE "COOLER" DAY BEHIND THE FRONTAL PASSAGE. HOWEVER,
FORECAST HIGH TEMPERATURES ARE STILL SLIGHTLY ABOVE NORMAL, IN THE
UPPER-60S TO MID-70S, AS CAA WILL BE FAIRLY WEAK. ON TUESDAY NIGHT,
THE LOW-LEVEL FLOW WILL TURN MORE EASTERLY AND SOUTHEASTERLY AS THE
SURFACE RIDGING SHIFTS EAST TO THE COAST. THIS WILL BRING INCREASING
CLOUDS AND ABOVE-NORMAL LOWS IN THE MID-40S TO LOWER-50S.
LONG TERM /WEDNESDAY THROUGH SUNDAY/
AS OF 420 AM MONDAY...
THE EXTENDED PERIOD WILL LARGELY BE DOMINATED BY A SUBTROPICAL HIGH
THAT REMAINS ANCHORED EAST OF FL FROM WEDNESDAY THROUGH AT LEAST THE
BEGINNING OF THE WEEKEND. BEHIND A WARM FRONT THAT MOVES THROUGH
CENTRAL NC ON WEDNESDAY, THE LOW-LEVEL FLOW WILL TURN
SOUTHERLY/SOUTHWESTERLY AROUND A WESTERN ATLANTIC SURFACE HIGH THAT
DROPS SOUTH AND EVENTUALLY BECOMES CENTERED NEAR BERMUDA. THUS PW
VALUES WILL INCREASE TO 150-200% OF NORMAL EACH DAY THROUGH THE
PERIOD. MEANWHILE A FRONTAL ZONE INITIALLY OVER THE PLAINS AND UPPER
MIDWEST WILL TRY TO REACH OUR AREA BEFORE STALLING OUT AS IT RUNS
INTO THE HIGH TO OUR SE. IT REMAINS UNCLEAR HOW CLOSE IT WILL GET,
WITH THE ECMWF TRYING TO BRING IT TO OUR NORTHERN ZONES ON SATURDAY
AS A BACKDOOR FRONT WHILE THE GFS KEEPS IT WELL DISPLACED FROM US.
AT THIS TIME, THE ONLY PRECIPITATION EACH DAY LOOKS TO BE ISOLATED
WAA-DRIVEN SHOWERS ACROSS MAINLY NORTHERN AND WESTERN PARTS OF
CENTRAL NC. BUT COVERAGE AND AMOUNTS SHOULD BE LIMITED BY THE
SUBTROPICAL HIGH TO OUR SE, AND BOTH GFS AND EC ENSEMBLE MEANS ARE
ONLY A FEW HUNDREDTHS TO MAYBE A TENTH OF AN INCH AT MOST. AT THE
VERY LEAST, THERE SHOULD BE A GOOD AMOUNT OF CLOUD COVER AND A
CHANCE OF LOW STRATUS EACH MORNING. BETTER RAIN CHANCES COME ON
SUNDAY AS THE HIGH FINALLY STARTS TO BREAK DOWN AND SHIFT EAST,
ALLOWING THE COLD FRONT AND BROAD MID/UPPER TROUGHING TO APPROACH
THE EASTERN SEABOARD. SOME STORMS CAN'T BE RULED OUT WITH THE FRONT
AS THERE LOOKS TO BE AT LEAST SOME INSTABILITY AROUND.
TEMPERATURES WILL BE QUITE WARM DURING THE PERIOD, AS HIGHS INCREASE
FROM LOWER-70S NORTH TO UPPER-70S SOUTH ON WEDNESDAY TO 80S ON
THURSDAY AND UPPER-80S TO LOWER-90S ON FRIDAY. LOWS SHOULD MAINLY BE
IN THE 60S. THE FORECAST ON FRIDAY IS CLOSE TO RECORD HIGHS FOR
APRIL 4 AT GSO, RDU AND FAY. IT WILL NOT BE A "DRY HEAT" EITHER AS
DEW POINTS WILL LARGELY BE IN THE 60S. THE WEEKEND'S TEMPERATURES
ARE LOWER CONFIDENCE AS THEY WILL DEPEND ON HOW QUICKLY THE FRONT IS
ABLE TO GET HERE, BUT LATEST GUIDANCE SLOWS IT DOWN AND DOESN'T
BRING IT THROUGH UNTIL LATE SUNDAY/EARLY MONDAY. SO FORECAST HIGHS
ARE STILL IN THE 80S BOTH DAYS. ONE BENEFIT OF THESE HIGHER DEW
POINTS IS THEY SHOULD KEEP RH'S WELL ABOVE LEVELS THAT WOULD
AGGRAVATE FIRE WEATHER CONCERNS.
AVIATION /12Z MONDAY THROUGH FRIDAY/
AS OF 750 AM MONDAY...
IFR TO LOW MVFR CEILINGS ACROSS CNTL NC THIS MORNING WILL GRADUALLY
LIFT THROUGH MVFR AND DISPERSE TO VFR WITH DAYTIME HEATING BY LATE
MORNING-EARLY AFTERNOON. MEANWHILE, A CLUSTER OR TWO OF SHOWERS AND
STORMS ARE FORECAST TO DEVELOP AND INTENSIFY FROM GA TO THE WRN
CAROLINAS AND SUBSEQUENTLY SPREAD EAST ACROSS CNTL NC LATE THIS
AFTERNOON THROUGH EVENING: FIRST AT INT/GSO BETWEEN 20-23Z AND LAST
AT RWI BETWEEN 23-02Z. AREAS OF BOTH MVFR CEILINGS AND SHOWERS WILL
THEN LINGER UNTIL A COLD FRONT AND FOLLOWING MUCH DRIER AIR
OVERSPREAD THE REGION LATER TONIGHT. PRE-FRONTAL SSWLY SURFACE WINDS
ARE EXPECTED TO MODESTLY STRENGTHEN AND BECOME AT LEAST OCCASIONALLY
GUSTY TO AROUND 20 KTS, AS CEILINGS LIFT AND MIXING INCREASE WITH
DAYTIME HEATING. NWLY WINDS SHOULD BE WEAKER, THOUGH WITH A RISK OF
AT LEAST INTERMITTENT GUSTINESS BEHIND THE COLD FRONT LATER TONIGHT.
OUTLOOK: AFTER BRIEF INFLUENCE FROM DRY, HIGH PRESSURE TUE-TU NIGHT,
RETURN FLOW, AND AN ASSOCIATED INCREASE IN LOW-LEVEL MOISTURE, WILL
LIKEWISE INCREASE THE RISK OF IFR-MVFR CONDITIONS AT INT/GSO WED
MORNING AND THROUGHOUT CNTL NC THU MORNING.
CLIMATE
RECORD HIGH TEMPERATURES:
APRIL 3:
KRDU: 91/1967
KFAY: 90/1934
APRIL 4:
KGSO: 86/1934
KRDU: 88/1934
KFAY: 93/1910
APRIL 5:
KGSO: 87/1942
KRDU: 90/1942
KFAY: 91/1942
APRIL 6:
KFAY: 91/2010
RECORD HIGH MINIMUM TEMPERATURES:
MARCH 31:
KGSO: 63/2022
KRDU: 65/2022
KFAY: 66/2022
APRIL 3:
KGSO: 64/1946
KRDU: 62/2000
KFAY: 65/1977
APRIL 4:
KGSO: 62/1999
KRDU: 63/2017
KFAY: 63/2017
APRIL 5:
KGSO: 60/2023
KRDU: 64/1910
KFAY: 64/2008
APRIL 6:
KGSO: 65/2023
KFAY: 69/2023
RAH WATCHES/WARNINGS/ADVISORIES
NONE.
SYNOPSIS...MWS
NEAR TERM...MWS
SHORT TERM...DANCO
LONG TERM...DANCO
AVIATION...MWS
CLIMATE...NWS
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