401
FXUS62 KRAH 200716
AFDRAH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
316 AM EDT SUN APR 20 2025
SYNOPSIS
A BACKDOOR COLD FRONT WILL DROP THROUGH VIRGINIA AND INTO NORTHERN
NORTH CAROLINA TODAY, THEN LINGER ACROSS NORTHERN NORTH
CAROLINA TONIGHT AND RETURN NORTH INTO THE MIDDLE ATLANTIC AS A
WARM FRONT ON MONDAY. A SLOW MOVING AND WEAKENING COLD FRONT
WILL MOVE EAST INTO THE CAROLINAS MONDAY NIGHT AND TUESDAY AND
THEN STALL ACROSS THE REGION THROUGH MUCH OF THE WORK WEEK.
NEAR TERM /THROUGH TONIGHT/
AS OF 355 PM SATURDAY...
* CONTINUED UNSEASONABLY WARM
A MID/UPR-LEVEL CYCLONE NOW OVER THE SOUTHWEST WILL PIVOT INTO THE
TX PANHANDLE VICINITY BY 12Z SUN, THEN LIFT NEWD ACROSS THE CNTL
PLAINS AND UPR MS VALLEY THROUGH THE END OF THE FORECAST PERIOD,
WHILE DEEPENING. DOWNSTREAM, AND ON THE NWRN THROUGH NRN PERIPHERY
OF A MID/UPR-LEVEL ANTICYCLONE FORECAST TO LINGER OFF THE SOUTH
ATLANTIC COAST, A RIDGE WILL PROGRESS ACROSS AND OFFSHORE THE MIDDLE
ATLANTIC. AS THE RIDGE PROGRESSES ACROSS AND EAST OF CNTL NC,
MID/UPR-LEVEL FLOW WILL BACK TO SWLY AND STRENGTHEN AMID WEAKLY
FALLING HEIGHTS, WITH AN ASSOCIATED THICKENING OF A PLUME OF CIRRUS
AND CIRROSTRATUS.
AT THE SURFACE, WARM, SUB-TROPICAL HIGH PRESSURE WILL CONTINUE TO
EXTEND WWD ACROSS THE SOUTH ATLANTIC STATES. MEANWHILE, A COLD FRONT
WILL MOVE IN BACKDOOR FASHION SWWD ACROSS SRN VA AND NRN NC SUN
AFTERNOON-EVENING, THEN STALL ALONG AN ARC FROM NEAR ROA TO RWI TO
HSE SUN NIGHT.
IT WILL BE CONTINUED VERY WARM IN CNTL NC SUN, BUT WITH LESS BREEZY
AND GUSTY SSWLY SURFACE WINDS WITHIN A LESSENING MSL PRESSURE
GRADIENT AHEAD OF THE APPROACHING BACK DOOR COLD FRONT AND WITH NEAR
PERSISTENCE HIGH TEMPERATURES MOSTLY 83-88 F, DESPITE THE
AFOREMENTIONED VEIL OF CONSIDERABLE HIGH CLOUDS. SURFACE CONVERGENCE
ALONG THE FRONT WILL FOCUS A TONGUE AND RELATIVE MAXIMUM OF SURFACE
DEWPOINTS IN THE LWR 60S F, AND A RELATED WEAK INSTABILITY AXIS OF
500-1000 J/KG OF MLCAPE. POINT FORECAST SOUNDINGS INDICATE MUCH OF
THAT BUOYANCY WILL BE CAPPED BY THE LINGERING INFLUENCE OF THE EML
NOW MAXIMIZED OVER THE SRN MIDDLE ATLANTIC/CAROLINAS. AN ASSOCIATED
AREA OF RELATIVELY MORE-CONCENTRATED (SCATTERED) AND LOCALLY DEEPER
CUMULUS WILL PROBABLY RESULT, BUT ANY WEAK UPDRAFTS THAT BREACH THE
CAP WILL BE HINDERED AND OPPOSED BY BOTH DRY ENTRAINMENT AND A LACK
OF ANY DEEPER LIFT/FORCING MECHANISM AMID THE PASSING RIDGE ALOFT.
ANY ASSOCIATED "PINHEAD", LIGHT SHOWER OR SPRINKLE SHOULD BE TOO
SHORT-LIVED AND ISOLATED TO WARRANT MENTIONABLE MEASURABLE POP.
POINT FORECAST SOUNDINGS ALSO INDICATE THE BACKDOOR FRONT MAY BE
ACCOMPANIED BY A SEVERAL HOUR PERIOD OF NELY SURFACE WINDS UP TO 15-
20 KTS IN GUSTS IMMEDIATELY FOLLOWING ITS PASSAGE, MAINLY DURING THE
EVENING OVER THE FAR NE PIEDMONT AND NRN COASTAL PLAIN. AN AREA OF
POST-FRONTAL CEILINGS AROUND 1000 FT AGL WILL ALSO LIKELY DEVELOP
FROM NERN NC AND PARTICULARLY POINTS NWD INTO CNTL VA SUN NIGHT-MON
MORNING. LOW TEMPERATURES SHOULD BE MAINLY UPR 50S TO LWR 60S.
SHORT TERM /MONDAY THROUGH MONDAY NIGHT/
AS OF 321 PM SATURDAY...
THE MID-LEVEL RIDGE WILL BEGIN TO BREAKDOWN MONDAY INTO TUESDAY, AS
A STRONG UPPER TROUGH LIFTS THROUGH THE GREAT LAKES REGION. A SERIES
OF WEAK SHORT-WAVES WILL TRAVERSE OVERHEAD THE REST OF THE WEEK.
MODELS HINT AT ANOTHER GREAT LAKES TROUGH AND ASSOCIATED EMBEDDED
MID-LEVEL PERTURBATIONS ADVECTING ACROSS THE EASTERN SEABOARD FRIDAY
INTO THE WEEKEND.
AT THE SFC, STRONG PRE-FRONTAL SWLY FLOW ON MONDAY WILL PROMOTE
ANOTHER DAY OF TEMPS REACHING THE MID 80S. DEW POINTS WILL
GENERALLY HOVER IN THE MID 50S, AS ANOMALOUS PWAT REMAINS LARGELY TO
OUR NORTHWEST. GIVEN LITTLE UPPER OR SFC FORCING, MONDAY SHOULD
REMAIN MOSTLY DRY. AS WE PIVOT TO THE OVERNIGHT, HOWEVER, THE
INFLUENCE OF THE UPPER TROUGH AND ASSOCIATED MOISTURE FLUX WILL
START TO INCH CLOSER TO OUR AREA. WILL MAINTAIN A DRY FORECAST
THROUGH 12Z TUESDAY FOR NOW, BUT WOULD NOT BE SURPRISED IF SOME
SHOWERS REACH THE NORTHWEST PIEDMONT IN THE EARLY TUESDAY MORNING
HOURS.
LONG TERM /TUESDAY THROUGH SATURDAY/
AS OF 310 AM SUNDAY...
* HIGH TEMPERATURES WILL BE WELL ABOVE NORMAL ON TUESDAY AND
SLIGHTLY ABOVE NORMAL FOR THE REST OF THE PERIOD.
* A WEAKENING FRONT WILL MOVE INTO THE AREA ON TUESDAY AND LINGER
FOR MUCH OF THE WORK WEEK PROVIDING A WEAK FOCUS FOR SCATTERED
SHOWERS AND A FEW STORMS.
* RAINFALL TOTALS FOR TUESDAY THROUGH SATURDAY WILL AVERAGE AROUND A
HALF INCH WITH SOMEWHAT GREATER AMOUNTS ACROSS SOUTHERN AREAS.
THE LONG TERM PERIOD BEGINS ON TUESDAY MORNING WITH AN EXITING MID
AND UPPER-LEVEL CLOSED LOW ACROSS QUEBEC AND A WEAKENED RIDGE JUST
EAST OF FL. THE REMNANTS OF A SHEARED OUT TROUGH WILL EXTEND FROM
THE CHESAPEAKE BAY SOUTHWEST ACROSS THE WESTERN CAROLINAS INTO THE
DEEP SOUTH. AN ASSOCIATED SURFACE COLD FRONT WHICH WILL BE WEAKENING
DROPS INTO THE WESTERN CAROLINAS MONDAY NIGHT AND MOVES INTO THE
CENTRAL CAROLINAS ON TUESDAY AND WEDNESDAY AND THEN WAIVERS AND
DISSIPATES ON THURSDAY AND FRIDAY.
DEEP LAYER MOISTURE WILL INCREASE WITH THE SOUTHWESTERLY FLOW ALOFT
RESULTING IN PW VALUES INCREASING TO AROUND 1.5 INCHES ACROSS
CENTRAL NC LATE TUESDAY AND INTO WEDNESDAY. THE ENHANCED MOISTURE
PERSISTS AND MAY MOISTEN FURTHER ON THURSDAY AND FRIDAY. WHILE THE
FORCING WON'T BE PARTICULARLY STRONG, LOW-LEVEL CONVERGENCE ALONG
THE FRONT, INCREASING MOISTURE, AND SOME MODEST LOW LEVEL
INSTABILITY WILL SUPPORT SHOWER/THUNDERSTORM CHANCES ACROSS CENTRAL
NC FOR THE TUESDAY THROUGH FRIDAY PERIOD. THE GREATEST POPS IN THE
50% RANGE ARE FOCUSED ON WEDNESDAY AND PERHAPS THURSDAY WITH THE
PRECIPITATION CHANCES GREATEST DURING THE AFTERNOON AND EVENING. A
SLIGHT ENHANCEMENT TO THE MID LEVEL FLOW WILL SUPPORT BULK-LAYER
SHEAR VALUES OF 20 TO 30 KTS MAINLY FOR WEDNESDAY THROUGH FRIDAY
WHICH COULD RESULT IN A STRONGER STORM OR TWO BUT NO WIDESPREAD
ORGANIZED SEVERE WEATHER IS EXPECTED DURING THE PERIOD. RAINFALL
TOTALS THROUGH FRIDAY NIGHT WILL AVERAGE AROUND A HALF INCH WITH
SLIGHTLY GREATER AMOUNTS PROBABLE ACROSS SOUTHERN AREAS IN THE
SOUTHERN PIEDMONT AND SANDHILLS WHERE GREATER INSTABILITY AND
MOISTURE IS EXPECTED.
HIGH TEMPERATURES WILL BE THE WARMEST ON TUESDAY WITH HIGHS IN THE
LOWER TO MID 80S WHICH IS ABOUT 8 TO 12 DEGREES ABOVE AVERAGE. HIGHS
WILL DROP BACK A BIT ON WEDNESDAY AND THURSDAY AND RANGE IN THE
UPPER 70S TO LOWER 80S WHICH IS ABOUT 4 TO 8 DEGREES ABOVE AVERAGE.
LOWS WILL RANGE MAINLY IN THE UPPER 50S TO LOWER 60S.
THE NEXT MID AND UPPER LEVEL TROUGH DEVELOPS ACROSS THE MIDWEST AND
GREAT LAKES ON FRIDAY AND APPROACHES THE CAROLINAS ON SATURDAY. AN
ASSOCIATED COLD FRONT WILL ALSO APPROACH THE AREA WITH ENHANCED
MOISTURE AND SOME STRONGER FLOW WHICH WILL SUPPORT AN UPTICK IN
SHOWER AND STORM COVERAGE. HIGHS WILL NUDGE UPWARD AHEAD OF THE
FRONT AND RANGE IN THE LOWER TO MID 80S ON SATURDAY. -BLAES
AVIATION /07Z SUNDAY THROUGH THURSDAY/
AS OF 150 AM SUNDAY...
24 HOUR TAF PERIOD: HIGH CONFIDENCE VFR CONDITIONS WILL PREVAIL,
WITH BROKEN HIGH CLOUDS THROUGH THE TAF PERIOD. WINDS SHOULD BE SLY
TO SWLY AT 5-10 KTS THROUGH 12Z. A BACKDOOR COLD FRONT WILL SLIP SWD-
SWWD INTO THE AREA TODAY, WITH WINDS BECOMING A BIT MORE SLY ACROSS
THE AREA AHEAD OF IT AND MORE SELY TO ESELY AND POTENTIALLY GUSTY
(15-20 KTS) ALONG AND BEHIND IT THIS EVE/TONIGHT (MAINLY AT KRWI,
POSSIBLY KRDU).
OUTLOOK: IFR-MVFR CEILINGS SHOULD DEVELOP BEHIND THE BACKDOOR COLD
FRONT TONIGHT, MAINLY ACROSS FAR NORTHEAST PORTIONS OF THE AREA,
POSSIBLY REACHING KRWI BETWEEN 06Z AND 12Z MON BEFORE RETREATING
NEWD OUT OF THE AREA MON MORN. THERE COULD BE SOME BORDERLINE LLWS
MON EVE/NIGHT AS THE LLJ STRENGTHENS TO AROUND 35 KTS AS IT PASSES
OVER CENTRAL NC. THERE WILL BE A CHANCE FOR CONVECTION AND FLIGHT
RESTRICTIONS TUE-THU AS A COLD FRONT MOVES INTO AND SETTLES OVER THE
AREA.
CLIMATE
RECORD HIGH TEMPERATURES:
APRIL 20:
KGSO: 94/1917
KRDU: 93/1896
KFAY: 94/1917
RECORD HIGH MINIMUM TEMPERATURES:
APRIL 20:
KGSO: 65/1941
KRDU: 67/1896
KFAY: 69/2011
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...BLAES
NEAR TERM...MWS
SHORT TERM...LUCHETTI
LONG TERM...BLAES
AVIATION...KC
CLIMATE...RAH
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