431
FXUS62 KRAH 211820
AFDRAH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
220 PM EDT MON APR 21 2025
SYNOPSIS
A WARM FRONT WILL RETREAT NORTHWARD ACROSS VA TODAY. A SLOW-MOVING
AND WEAKENING COLD FRONT WILL MOVE EAST INTO THE CAROLINAS TONIGHT
AND TUESDAY AND STALL ACROSS THE REGION THROUGH MUCH OF THE WORK
WEEK.
NEAR TERM /THROUGH TONIGHT/
AS OF 1140 AM MONDAY...
THE PREVIOUS FORECAST AND RATIONALE ARE ON TRACK; AND NO APPRECIABLE
GRIDDED FORECAST CHANGES WERE NEEDED AGAIN THIS MORNING. THE
BACKDOOR FRONT, WHICH HAD OVERNIGHT SETTLED INTO THE NRN COASTAL
PLAIN, HAS RETREATED NWD IN THE PAST HOUR OR TWO AND OUT OF NRN
HALIFAX AND WARREN CO. ALL OF CNTL NC WILL CONSEQUENTLY REMAIN IN
THE UNSEASONABLY WARM, WARM SECTOR TODAY, WITH PREVIOUSLY FORECAST
HIGH TEMPERATURES CENTERED IN THE MID 80S.
PREV DISCUSSION
/ISSUED 300 AM EDT MON APR 21 2025/
* CONTINUED UNSEASONABLY WARM
ALOFT, THE S/W (OVER THE UPPER MS VALLEY AS OF 06Z) WILL LIFT NWD
ACROSS THE WRN GREAT LAKES AND SRN ONTARIO, CANADA, WHILE THE
ANTICYCLONE WEAKENS OFF THE EAST COAST OF FL. AT THE SURFACE, A WARM
FRONT WILL LIFT NEWD THROUGH THE AREA TODAY, WITH A PIEDMONT TROUGH
SETTING UP THIS EVE AS A COLD FRONT APPROACHES THE APPALACHIANS FROM
THE WEST. THE PARENT LOW WILL OCCLUDE OVER SE CANADA TONIGHT, WITH
THE ATTENDANT COLD FRONT MOVING ACROSS THE NORTHEAST US AND NRN MID-
ATLANTIC. THE WEATHER SHOULD LARGELY REMAIN DRY TODAY AND MOST OF
TONIGHT. EXPECT SHOWERS TO APPROACH FROM THE WEST LATE TONIGHT,
POSSIBLY MOVING INTO THE NW PIEDMONT EARLY TUE MORN. WINDS COULD
BECOME A BIT BREEZY AGAIN THIS AFT/EARLY EVE AS THE PRESSURE
GRADIENT INCREASES AHEAD OF THE FRONT, WITH GUSTS GENERALLY IN THE
15-20 MPH RANGE, HIGHEST OVER THE NORTHWEST PIEDMONT. OTHERWISE,
EXPECT ANOTHER UNSEASONABLY WARM DAY, WITH HIGHS IN THE LOW TO MID
80S AND LOWS IN THE LOW TO MID 60S.
SHORT TERM /TUESDAY AND TUESDAY NIGHT/
AS OF 206 PM MONDAY...
A SFC COLD FRONT WILL SLOWLY SLUDGE SOUTH THROUGH CENTRAL NC TUESDAY
AS AN UPPER TROUGH LIFTS ACROSS THE GREAT LAKES/NORTHEAST. A SERIES
OF MCVS/PERTURBATIONS WILL TRAVERSE OVERHEAD AND WILL COMBINE WITH
SFC CONVERGENCE ALONG THE BOUNDARY TO TRIGGER SCATTERED SHOWERS AND
STORMS.
TEMPERATURES WILL RISE INTO THE UPPER 70S TO MID 80S TUESDAY
AFTERNOON. AS SUCH, ANYWHERE FROM 1000 TO 1500 J/KG OF MLCAPE IS
FORECAST TO DEVELOP PRIMARILY ALONG AND SOUTH OF THE FRONT. RAIN
EARLY IN THE DAY SHOULD BE MOSTLY SHOWERY IN NATURE, BUT SCATTERED
THUNDERSTORMS WILL DEVELOP IN THE AFTERNOON. THE MCV TRAIN WILL
CONTINUE INTO THE OVERNIGHT PERIOD, AND AS SUCH, EXPECT SHOWERS AND
STORMS TO CONTINUE THROUGH EARLY WEDNESDAY MORNING.
SEVERE WEATHER WISE, GUIDANCE SUGGESTS ~35 KTS OF EFFECTIVE SHEAR
WILL DEVELOP TUESDAY AFTERNOON AND EVENING. AS SUCH, A FEW ISOLATED
STORMS COULD BECOME STRONG TO SEVERE. FORECASTED HODOGRAPHS SHOW
SIGNS OF SOME ELONGATION IN THE VICINITY OF ALBEMARLE NORTHEAST
THROUGH RALEIGH/DURHAM TO ROANOKE RAPIDS (LATEST RUNS OF THE HREF
DEPICT A CLUSTERING OF LOW TO MID-LEVEL HELICITY SWATH MAXIMA IN
THIS VICINITY AS WELL). LOCATIONS ALONG AND SOUTH OF THIS IMAGINARY
LINE WOULD HAVE THE BEST CHANCE FOR A STRONGER STORM. PRIMARILY
STRAIGHT HODOGRAPHS WOULD SUGGEST THE PRIMARY THREAT WITH ANY
STRONGER STORM WOULD BE DAMAGING WIND GUSTS OR SMALL HAIL. THE STP
PARAMETER IS NEAR ZERO FOR MUCH OF OUR AREA INDICATING LITTLE TO NO
TORNADO THREAT. HOWEVER, THERE IS A SIGNAL FOR A STRONG SEA BREEZE
AT THE COAST TUESDAY WHICH WILL LIKELY PENETRATE INTO OUR SOUTHERN
COASTAL PLAIN AND SANDHILLS BY TUESDAY EVENING. AS SUCH, WOULD NOT
BE SURPRISED IF LOCALLY ENHANCED UPDRAFTS/SUPERCELLS DEVELOP ALONG
THE BOUNDARY IN WHICH CASE A QUICK SPIN UP AND/OR LARGER HAIL COULD
BE POSSIBLE.
THE SEVERE THREAT SHOULD LARGELY WANE WITH LOSS OF HEATING. HOWEVER,
SOME HIGH-RES GUIDANCE IS A BIT MORE BULLISH ON CONTINUING
CONVECTION OVERNIGHT WHILE MAINTAINING AT LEAST SOME INSTABILITY AND
SHEAR ACROSS SOUTHERN AREAS. AS SUCH, CAN'T RULE OUT A STRONGER
ISOLATED CELL OVERNIGHT ESPECIALLY IF ANY STRONGER MCVS TRICKLE
OVERHEAD. ADDITIONALLY, THE HREF LPMM FIELD DOES INDICATE SOME
POTENTIAL FOR LOCALLY HIGHER QPF OVERNIGHT IN THE SANDHILLS/COASTAL
PLAIN VICINITY. NOT EXPECTING WIDESPREAD FLASH FLOODING BY ANY
MEANS, BUT ISOLATED URBAN AREAS WILL NEED TO BE MONITORED.
WARM OVERNIGHT LOWS IN THE UPPER 50S TO LOWER 60S IS EXPECTED.
LONG TERM /WEDNESDAY THROUGH MONDAY/
AS OF 220 PM MONDAY...
RAIN CHANCES GENERALLY STAY IN THE AREA FROM WEDNESDAY THROUGH
FRIDAY DUE TO A STALLING FRONT. THE COLD FRONT SHOULD MOVE THROUGH
THE REGION ON WEDNESDAY AND STAY TO OUR SOUTH ON THURSDAY BEFORE
MOVING NORTH THROUGH THE REGION ON FRIDAY AS A WARM FRONT. EACH DAY
THERE WILL BE A CHANCE OF SHOWERS WITH THE POTENTIAL OF EMBEDDED
THUNDERSTORMS WHERE THE FRONTAL BOUNDARY LINES UP WITH DIURNAL
HEATING AND MID-LEVEL PERTURBATIONS IN THE FLOW. THUS, RAIN AND
STORM CHANCES ARE MAXIMIZED IN THE AFTERNOON AND EVENING EACH DAY.
RAIN CHANCES WILL CONTINUE SATURDAY AFTERNOON THROUGH EVENING, AS
ANOTHER COLD FRONT APPROACHES THE REGION FROM THE WEST.
MAXIMUM TEMPERATURES WEDNESDAY THROUGH SATURDAY SHOULD BE ABOUT 5
DEGREES ABOVE NORMAL ON AVERAGE, WITH HIGHS GENERALLY EXPECTED IN
THE MID 70S TO LOW 80S. THE WARMEST DAY SHOULD BE ON SATURDAY WITH
TEMPERATURES IN THE MID 80S IN THE SOUTH. MINIMUM TEMPERATURES
SHOULD BE ABOUT 15 DEGREES ABOVE NORMAL, WITH LOWS IN THE MID 50S TO
LOW 60S NIGHTLY.
THE COLD FRONT SHOULD MOVE THROUGH THE REGION SATURDAY NIGHT,
DROPPING HIGH TEMPERATURES INTO THE MID 70S SUNDAY AFTERNOON, WITH
LOWS DROPPING TO AROUND 50. MONDAY SHOULD BE A FEW DEGREES WARMER AS
A SURFACE HIGH BUILDS BEHIND THE FRONT.
AVIATION /18Z MONDAY THROUGH SATURDAY/
AS OF 200 PM MONDAY...
* MAINLY VFR, EXCEPT WITH A CHANCE OF SHOWERS AND FLIGHT
RESTRICTIONS AT INT/GSO BETWEEN 12-18Z TUE.
A SSWLY BREEZE WILL GUST TO AROUND 20 KTS THIS AFTERNOON, THEN
DIMINISH AFTER SUNSET. VFR CONDITIONS ARE OTHERWISE EXPECTED UNTIL A
A COUPLE OF MID-LEVEL DISTURBANCES, SHOWERS, AND RAIN-COOLED OUTFLOW
OVERSPREAD THE NC PIEDMONT ON TUE. NEAR LOW-LEVEL WIND SHEAR
CONDITIONS WILL ALSO BE POSSIBLE FROM RDU TO ESPECIALLY POINTS NEWD
ALONG THE MIDDLE ATLANTIC COAST LATE TONIGHT-TUE MORNING.
OUTLOOK: A SYNOPTIC FRONT AND PRECEDING OUTFLOW BOUNDARY/EFFECTIVE
FRONT WILL WAVER OVER THE CAROLINAS THIS WEEK, WITH AN ASSOCIATED
CHANCE OF CONVECTION AND FLIGHT RESTRICTIONS MAXIMIZED EACH
AFTERNOON-EVENING, AND ALSO A CHANCE OF LATE NIGHT-EARLY MORNING IFR-
MVFR CEILINGS.
CLIMATE
RECORD HIGH MINIMUM TEMPERATURES:
APRIL 21:
KGSO: 64/1927
KRDU: 70/1896
KFAY: 68/2017
APRIL 22:
KGSO: 63/1967
KRDU: 66/1909
KFAY: 64/1963
RAH WATCHES/WARNINGS/ADVISORIES
NONE.
SYNOPSIS...MWS/BLAES
NEAR TERM...MWS/KC
SHORT TERM...LUCHETTI
LONG TERM...HELOCK
AVIATION...MWS
CLIMATE...RAH
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