816
FXUS62 KRAH 211952
AFDRAH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
352 PM EDT MON APR 21 2025
SYNOPSIS
A WARM FRONT WILL RETREAT NORTHWARD ACROSS THE MIDDLE ATLANTIC COAST
THROUGH TONIGHT. MEANWHILE, A SLOW-MOVING AND WEAKENING COLD FRONT
WILL MOVE EAST INTO THE CAROLINAS BY TUESDAY AND TUESDAY NIGHT, THEN
REMAIN QUASI-STATIONARY THERE THROUGH MUCH OF THE WORK WEEK.
NEAR TERM /THROUGH TONIGHT/
AS OF 350 PM MONDAY...
* CONTINUED UNSEASONABLY WARM, AND MAINLY DRY, WITH A FEW WEAK (AND
PROBABLY WEAKENING) SHOWERS OVER THE NW NC PIEDMONT TUE MORNING
IN THE MID/UPR-LEVELS, A SUB-TROPICAL HIGH SITUATED JUST OFF THE
SOUTH ATLANTIC COAST WILL CONTINUE TO WEAKEN. ON ITS NWRN PERIPHERY,
A RIBBON OF CONVECTIVELY-AMPLIFIED VORTICITY AND TRAIN OF SMALL MCVS
NOW STRETCHING FROM THE WRN NY/PA SWWD ACROSS THE TN AND LWR MS
VALLEYS, AND ASSOCIATED MOIST AXIS CHARACTERIZED BY PWS AROUND 1.5",
WILL EDGE EWD INTO THE NW NC PIEDMONT EARLY TUE MORNING (BETWEEN 9-
12Z).
AT THE SURFACE, CNTL NC WILL REMAIN IN THE WARM SECTOR ON THE NW
PERIPHERY OF THE SUB-TROPICAL HIGH OFF THE SOUTH ATLANTIC COAST.
MEANWHILE, A SYNOPTIC COLD FRONT NOW STRETCHING FROM CNTL LAKE ERIE
AND CNTL OH SWWD THROUGH W-CNTL TN, EXTREME NWRN MS, AND NRN LA,
WILL MOVE SLOWLY EWD AND EXTEND FROM ERN PA SWWD ALONG THE BLUE
RIDGE BY 12Z TUE. THE FRONT WILL BE PRECEDED BY AN OUTFLOW BOUNDARY,
AND LEADING EDGE OF ONGOING DEEP CONVECTION, FROM THE TN VALLEY TO
CNTL MS, WHICH WILL LIKEWISE EDGE EWD AND INTO THE NC FOOTHILLS AND
FAR NW PIEDMONT THROUGH THE SAME TIME. THE STRENGTH AND LOCATION OF
THIS BOUNDARY, AND PROBABLE DIFFERENTIAL HEATING THROUGH MIDDAY TUE
ALONG ITS ASSOCIATED MID-LEVEL CLOUD BAND, WILL PROBABLY PROVE
INFLUENTIAL IN LOCATION OF GREATEST CONVECTIVE CLUSTERING AND SEVERE
POTENTIAL IN CNTL NC ON TUE.
A SCATTERING, ON AVERAGE, OF FLAT DIURNAL CUMULUS WITH HEATING INTO
THE 80S F THIS AFTERNOON WILL DIMINISH AROUND SUNSET, AS WILL A
GUSTY SSWLY BREEZE. THE FORECAST FOR TONIGHT WILL OTHERWISE BE
CHARACTERIZED BY LIGHT SSWLY STIRRING AND MAINLY CLEAR/FAIR SKIES
FOR MOST OF THE NIGHT, FOLLOWED BY THE ARRIVAL OF THE AFOREMENTIONED
MID-LEVEL CLOUD BAND, ASSOCIATED CLOUDY OR MOSTLY SO CONDITIONS, AND
A CHANCE OF A FEW WEAKENING SHOWERS OVER THE NW PIEDMONT. LOW
TEMPERATURES MOSTLY IN THE LWR-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
NEAR TERM...MWS
SHORT TERM...LUCHETTI
LONG TERM...HELOCK
AVIATION...MWS
CLIMATE...RAH
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