932
FXUS62 KRAH 200001
AFDRAH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
700 PM EST TUE NOV 19 2024
SYNOPSIS
HIGH PRESSURE CENTERED OFFSHORE WILL EXTEND OVER THE SOUTHEAST COAST
THROUGH TONIGHT, AS AN UPPER LEVEL DISTURBANCE PASSES THROUGH THE
REGION. A SURFACE COLD FRONT WILL CROSS THE AREA WEDNESDAY EVENING,
USHERING IN COLDER AIR FOR LATE WEEK.
NEAR TERM /THROUGH TONIGHT/
AS OF 234 PM TUESDAY...
THE MIMIC-TPW SATELLITE PRODUCT SHOWS THE ANOMALOUS MOISTURE PLUME
CONTINUES TO REMAIN TO OUR WEST THIS AFTERNOON. HERE LOCALLY, WE
HAVE SEEN SOME MOISTENING OF THE COLUMN, BUT SUB-1 INCH PWAT REMAINS
OVER MUCH OF OUR AREA. AS SUCH, WHILE WE'VE HAD SOME WEAK RADAR ECHO
RETURNS TRAVERSE THE NC/SC BORDER, WE'VE YET TO SEE ANY REPORTS OF
MEASURABLE RAIN AT THE SFC. CAMS CONTINUE TO SUGGEST THE SWATH OF
RAIN CURRENTLY ACROSS GA/SC WILL MOSTLY DISSIPATE WITH TIME THIS
EVENING. HOWEVER, CAN'T RULE OUT A FEW TRACE OBSERVATIONS ACROSS OUR
SOUTHERN AREAS THROUGH TONIGHT WITH THIS DIMINISHING BAND.
AS WE PIVOT TO THE OVERNIGHT PERIOD, THE SATURATION DEPTH SHOULD
DEEPEN WITH TIME, AS A FEW WEAK EMBEDDED MID-LEVEL PERTURBATIONS
SLIDE ACROSS THE SOUTHEAST. THE LATEST HRRR RUNS HAVE GENERATED A
BIT MORE PRECIP THROUGH 12Z WEDNESDAY, AND ARE MORE IN LINE WITH THE
12Z GUIDANCE FROM THE NAM NEST/FV3/ARW RUNS. REGARDLESS, EXPECT
SCATTERED SHOWERS THROUGH THE OVERNIGHT PERIOD WITH ANYWHERE FROM A
FEW HUNDREDS TO A FEW TENTHS OF ACCUMULATION. OVERNIGHT LOWS IN THE
UPPER 50S ARE EXPECTED UNDER CLOUDY SKIES.
SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/
AS OF 240 PM TUESDAY...
LOW PRESSURE WILL BE OVER LAKE ERIE WEDNESDAY MORNING, WITH A WARM
FRONT EXTENDING SOUTHEAST ACROSS PENNSYLVANIA AND THE DELMARVA
PENINSULA WHILE A COLD FRONT WILL EXTEND SOUTH ALONG THE APPALACHIAN
MOUNTAINS. THE BULK OF RAINFALL SHOULD HAVE MOVED TO THE EAST
OVERNIGHT, WITH DECLINING CHANCES OF RAIN THROUGH THE MORNING FROM
WEST TO EAST. HOWEVER, THE CHANCE OF RAIN SHOULD INCREASE AGAIN IN
THE AFTERNOON, BOTH ALONG THE I-95 CORRIDOR WHERE THERE WILL BE MORE
INSTABILITY AS WELL AS FARTHER TO THE WEST ALONG THE COLD FRONT
ITSELF. DID NOT SEE ENOUGH INSTABILITY TO ADD THUNDER TO THE
FORECAST, BUT THINK THAT THESE TWO SEPARATE AREAS WARRANT HIGHER
POPS THROUGH THE AFTERNOON. WITH THE COLD FRONT APPROACHING THE
TRIANGLE WEDNESDAY EVENING, POPS SHOULD COME TO AN END DURING THE
EVENING HOURS, ALLOWING FOR DRY CONDITIONS AFTER MIDNIGHT. CANNOT
RULE OUT SOME PATCHY FROST EARLY THURSDAY MORNING, ALTHOUGH THIS
SHOULD BE SHORT-LIVED.
THE WIND WILL PICK UP BEHIND THE COLD FRONT WEDNESDAY EVENING,
SLACKEN BRIEFLY LATE WEDNESDAY NIGHT, THEN PICK UP AGAIN ON THURSDAY
DUE TO A STRONGER PRESSURE GRADIENT BETWEEN TWO SEPARATE LOWS (THE
WEDNESDAY LOW DEPARTING OFF THE NEW ENGLAND COAST PLUS A SECOND LOW
OVER THE NORTHERN GREAT LAKES) AND HIGH PRESSURE BUILDING ACROSS
TEXAS. SUSTAINED WINDS SHOULD BE 10-15 MPH WITH GUSTS BETWEEN 20-30
MPH. THERE ARE STILL POSSIBLE FIRE CONCERNS ON THURSDAY WITH THE
GUSTY WIND AS WELL AS RELATIVELY HUMIDITY VALUES BETWEEN 30-40% IN
MOST LOCATIONS. THIS COULD PROMPT AN INCREASED FIRE DANGER
STATEMENT. THERE WILL BE MORE POTENTIAL FOR FROST LATE THURSDAY
NIGHT, ALTHOUGH THE RISK OF FROST FORMATION MAY BE TEMPERED BY WINDS
REMAINING SLIGHTLY HIGHER (5-10 MPH).
THE STRING OF ABOVE NORMAL TEMPERATURES WILL COME TO AN END AFTER
WEDNESDAY, WITH HIGHS RANGING FROM THE MID 60S TO THE MID 70S. LOWS
WEDNESDAY NIGHT WILL BE 15-20 DEGREES COLDER THAN TONIGHT WITH THE
PASSAGE OF THE COLD FRONT, RANGING FROM THE MID 30S TO THE MID 40S.
THURSDAY'S HIGHS WILL ONLY BE IN THE 50S, RETURNING TO BELOW NORMAL
VALUES. THURSDAY NIGHT'S LOWS WILL BE IN THE 30S, AND CANNOT RULE
OUT A FEW COUNTIES POTENTIALLY NEEDING A FREEZE WARNING.
LONG TERM /FRIDAY THROUGH TUESDAY/
AS OF 255 PM TUESDAY...
* BRISK FRI MORNING WITH WIND CHILLS IN THE LOW 30S TO UPPER 20S
FROM 2 AM THROUGH 8 AM.
* PATCHY FROST POSSIBLE SAT AND SUN MORNING WITH MODERATING
TEMPERATURES THROUGH EARLY NEXT WEEK.
AN UNSEASONABLY DEEP AND STRONG MID/UPPER LEVEL LOW AND ASSOCIATED
OCCLUDED SURFACE LOW PRESSURE WILL BE SITUATED OVER THE MID-ATLANTIC
FRI MORNING. THE NEWLY DEPOSITED CP AIRMASS FROM THE CANADIAN
AIRMASS AND TIGHT PRESSURE GRADIENT FROM THE DEEP 990MB LOW TO OUR
NORTH WILL PROMPT A BRISK WESTERLY WINDS THROUGHOUT THE DAY WITH
HIGHS ONLY REACHING THE LOW/MID 50S AND 10-15 MPH WINDS WITH
FREQUENT GUSTS 20-30 MPH.
THE SURFACE LOW WILL BEGIN TO LIFT NORTHEAST ON SAT AS SURFACE HIGH
PRESSURE BEGINS TO WEAKEN AS IT SETTLES OVER THE NORTHERN GOM STATES
AND FL INTO SUN. THE CONTINUED TIGHT PRESSURE GRADIENT OVER THE AREA
SHOULD RESULT IN ANOTHER DAY OF BRISK WINDS WITH GUSTS 20 TO 30 MPH.
POINT SOUNDINGS AND MOMENTUM TRANSFER FROM THE TOP OF THE MIXED
LAYER SHOW SOME INFREQUENT GUSTS OF 35 MPH WILL BE POSSIBLE. THE
PRESSURE GRADIENT WILL GRADUALLY RELAX THROUGH THE NIGHT INTO SUN
MORNING. MINUS ANY OROGRAPHIC CIRRUS DEVELOPMENT, CALM AND CLEAR
CONDITIONS WILL PROMPT RADIATIONAL COOLING AND THE COOLEST PERIOD IN
THE EXTENDED.
TEMPERATURES WILL CONTINUE TO MODERATE INTO EARLY NEXT WEEK AS THE
SURFACE HIGH SLIPS OFF THE SOUTHEAST COAST AND TOWARDS BERMUDA. LOW
AMPLITUDE DISTURBANCES RIPPLING THROUGH THE NEARLY ZONAL FLOW WOULD
RESULT IN PERIODS OF CLOUDINESS AND PERHAPS SOME LIGHT RAIN CHANCES
EARLY NEXT WEEK, ALTHOUGH PREDICTABILITY IS LOW AT THIS TIME RANGE.
AVIATION /00Z WEDNESDAY THROUGH SUNDAY/
AS OF 700 PM TUESDAY...
CONFIDENCE IS HIGH THAT POOR AVIATION CONDITIONS, BRIEF MVFR CIGS
DROPPING QUICKLY TO IFR/LIFR, WILL DOMINATE THROUGH THE NEXT 24 HRS
ACROSS CENTRAL NC, AS AN UPPER LEVEL DISTURBANCE PASSES OVER THE
REGION, FOLLOWED CLOSELY BY AN APPROACHING SURFACE COLD FRONT. WE'RE
ALREADY SEEING SCT-BKN MVFR CIGS IN THE W PIEDMONT (INT/GSO), AND
THESE LOW CLOUDS WILL SPREAD FROM W TO E WITH LOWERING BASES
OVERNIGHT THROUGH WED MORNING. INT/GSO ARE EXPECTED TO DROP TO
IFR/LIFR BY 07Z, RDU/FAY BY 12Z, AND RWI BY 16Z. PATCHY LIGHT RAIN
WILL PASS THROUGH THE REGION AND MAINLY AFFECT INT/GSO/FAY LATE
TONIGHT THROUGH EARLY WED, THEN SCATTERED SHOWERS ARE POSSIBLE
AREAWIDE WED AFTERNOON, BUT OVERALL VSBYS SHOULD BE MVFR TO VFR AS
ANY RAIN IS NOT EXPECTED TO BE HEAVY. SURFACE WINDS WILL BE LIGHT
FROM THE S OR SW, MOSTLY UNDER 10 KTS, BUT VERY LATE IN THE PERIOD
(AFTER 22Z), AS THE FRONT GETS CLOSE TO THE INT/GSO, WINDS THERE
WILL INCREASE AND SHIFT AROUND TO WESTERLY WITH SOME GUSTS TO 15-25
KTS POSSIBLE.
LOOKING BEYOND 00Z THU, AS THE COLD FRONT SHIFTS E THROUGH CENTRAL
NC THROUGH WED EVENING, CIGS WILL LIFT TO MVFR THEN VFR OVER JUST A
COUPLE HOURS' TIME, WITH WINDS ABRUPTLY SHIFTING TO BE FROM THE W OR
WNW WHILE INCREASING TO SUSTAINED 10-20 KTS GUSTING TO 20-25 KTS FOR
A FEW HOURS IN THE EVENING THROUGH EARLY OVERNIGHT HOURS WED NIGHT.
WINDS WILL QUIET DOWN TO UNDER 12 KTS AFTER 07Z W AND 10Z E EARLY
THU, THEN INCREASE AGAIN AFTER 14Z THU WITH GUSTS TO 20-30 KTS
POSSIBLE DURING THE DAY AT ALL SITES. GUSTY WINDS ARE AGAIN LIKELY
FRI. OVERALL, VFR CONDITIONS WILL PREVAIL THROUGH THE WEEKEND. -GIH
RAH WATCHES/WARNINGS/ADVISORIES
NONE.
SYNOPSIS...LUCHETTI
NEAR TERM...LUCHETTI
SHORT TERM...GREEN
LONG TERM...SWIGGETT
AVIATION...HARTFIELD
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