200
FXUS62 KRAH 310827
AFDRAH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
427 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 /TODAY AND TONIGHT/
AS OF 335 PM SUNDAY...
* THERE IS A ENHANCED/LEVEL 3 RISK FOR SEVERE STORMS ACROSS CENTRAL
NC MONDAY
ON MONDAY MORNING, LOW PRESSURE SHOULD BE SLIGHTLY NORTH OF LAKE
ONTARIO, WITH A COLD FRONT EXTENDING SOUTH THROUGH OHIO INTO ALABAMA
AND TRAILING WEST INTO TEXAS. ALTHOUGH THERE IS A LEVEL 3/ENHANCED
RISK ACROSS THE AREA, THERE IS STILL LOTS OF UNCERTAINTY AS TO HOW
THE SEVERE WEATHER EVENT WILL EVOLVE. THERE ARE AT LEAST THREE PARTS
OF THE FORECAST WHERE UNCERTAINTY WILL HAVE A MAJOR INFLUENCE IN THE
FORECAST:
1) THE GFS DEPICTS A WEAK LOW TRACKING ALONG THE COASTLINE PRODUCING
SOME MORNING SHOWERS ACROSS EASTERN COUNTIES. LEFTOVER CLOUDS FROM
THESE SHOWERS COULD LIMIT INSTABILITY IN THE EAST.
2) HIGH-RESOLUTION MODELS IN THE HREF DO NOT SHOW A SOLID LINE OF
THUNDERSTORMS, BUT APPEAR TO BE DISCRETE CELLS. THE MODE WILL AFFECT
THE TYPE OF SEVERE WEATHER THAT DEVELOPS.
3) A SECONDARY LINE OF THUNDERSTORMS IS DEPICTED ON SOME HIGH-
RESOLUTION MODELS AFTER THE INITIAL LINE MOVES THROUGH, AFFECTING
PRIMARILY THE TRIAD IN THE LATE EVENING.
THE BROAD THINKING REMAINS THAT THE COLD FRONT AND AREA OF
THUNDERSTORMS WILL REACH THE TRIAD BETWEEN 2-6PM, THE TRIANGLE
BETWEEN 4-8PM, AND THE I-95 CORRIDOR BETWEEN 6-9PM. ALL HAZARDS
(WIND, HAIL, TORNADOES) REMAIN A POSSIBILITY. WITH THE MID-DAY
UPDATE, THE STORM PREDICTION CENTER HAS REDUCED THE CHANCE OF SEVERE
HAIL ACROSS THE REGION, BUT INCREASED THE CHANCE OF SEVERE WIND
ACROSS THE ENTIRE AREA. FLASH FLOODING SHOULD NOT BE A WIDESPREAD
THREAT WITH THE STORMS MOVING THROUGH RELATIVELY QUICKLY, WITH HALF
AN INCH TO THREE QUARTERS OF AN INCH OF RAIN FORECAST. THE BULK OF
THE RAIN SHOULD COME TO AN END BY EARLY MORNING. HIGHS WILL BE
AROUND 80 DEGREES IN MOST LOCATIONS, ALTHOUGH IN THE MID TO UPPER
70S IN THE TRIAD WITH THE EARLIER ARRIVAL OF SHOWERS/THUNDERSTORMS.
LOWS WILL DEPEND ON HOW QUICKLY COOLER AIR MOVES IN BEHIND THE FRONT.
- WHILE THE TRIAD WILL LIKELY FALL INTO THE UPPER 40S, TEMPERATURES
MAY ONLY FALL INTO THE MID TO UPPER 50S ALONG THE I-95 CORRIDOR.
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 /06Z MONDAY THROUGH FRIDAY/
AS OF 230 AM MONDAY...
IFR TO LOW MVFR CEILINGS WILL CONTINUE TO EXPAND ACROSS CNTL NC
EARLY THIS MORNING, THEN GRADUALLY LIFT TO MVFR, AND DISPERSE TO VFR
ESPECIALLY EAST OF INT/GSO, 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, FOLLOWED BY A RISK OF SIMILARLY, MODESTLY STRONG
NWLY WINDS AND GUSTS 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.
RAH WATCHES/WARNINGS/ADVISORIES
NONE.
SYNOPSIS...MWS
NEAR TERM...GREEN
SHORT TERM...DANCO
LONG TERM...DANCO
AVIATION...MWS
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