107
FXUS62 KRAH 200710
AFDRAH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
210 AM EST WED NOV 20 2024
SYNOPSIS
A STRONG COLD FRONT WILL CROSS THE AREA THIS EVENING, USHERING IN
COLDER AIR LATER TONIGHT THROUGH LATE WEEK. A SLOW MODERATING TREND
IS EXPECTED OVER THE WEEKEND.
NEAR TERM /THROUGH TONIGHT/
AS OF 835 PM TUESDAY...
MOST OF THE SHOWER ACTIVITY TONIGHT IS STILL LINGERING TO THE SOUTH.
AS THE MOISTURE PLUME FROM THE SOUTH SURGES INTO THE REGION
OVERNIGHT EXPECT AN INCREASE IN SHOWER ACTIVITY. ADJUSTED POPS
OVERNIGHT TO SHOW THE INCREASE IN POPS LATE TONIGHT INTO THE
MORNING. OVER THE NEXT SEVERAL HOURS SHOWERS FROM SC COULD DRIFT
INTO NC BUT ARE EXPECTED TO BE LIGHT WITH LITTLE ACCUMULATION. THE
HEAVIER SHOWERS ARE EXPECTED TO MOVE IN EARLY MORNING AND CLEAR OUT
AGAIN SHORTLY AFTER SUNRISE. SOME AREAS COULD SEE ANY WHERE FROM A
FEW HUNDREDS TO A FEW TENTHS OF ACCUMULATION, ALL TOTALS GENERALLY
BELOW QUARTER OF AN INCH. SKIES WILL BE CLOUDY WHICH WILL HELP
TEMPERATURES STAY IN THE UPPER 50S OVERNIGHT, WHICH IS ABOUT 20
DEGREES ABOVE AVERAGE.
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 210 AM WEDNESDAY...
AN ANOMALOUSLY STRONG MID-LEVEL TROUGH AND ASSOCIATED SURFACE LOW
OVER THE MID-ATLANTIC FRI WILL BRING BRISK WNW WINDS GUSTING AT
TIMES TO BETWEEN 20 AND 30 MPH. INFREQUENT GUSTS TO 35 MPH ARE ALSO
POSSIBLE PER POINT FORECAST SOUNDINGS AND MOMENTUM TRANSFER. MORNING
WIND CHILLS IN THE UPPER 20S TO LOW 30S WILL MAKE IT FEEL QUITE
CHILLY. HIGHS WILL BE SOME 9-12 DEGREES BELOW AVERAGE IN THE UPPER
40S TO LOWER 50S AMID STRONG LOW-LEVEL CAA. FORECAST RH LEVELS ARE
NOT EXPECTED TO BE AS LOW AS THU GIVEN LOWER MAXT VALUES, BUT STILL
RANGE IN THE 30-40 PERCENT RANGE. A LOW-END FIRE DANGER THREAT MAY
EXIST IN THE AFTERNOON WITH PEAK MIXING. WINDS ARE EXPECTED TO STAY
ELEVATED FRI NIGHT UNDER THE MOIST CYCLONIC FLOW ALOFT, ADDITIONALLY
FAVORING AREAS OF STRATOCUMULUS CLOUDS. THIS SHOULD KEEP LOWS IN THE
MID TO UPPER 30S WITH ONLY PATCHY FROST OVER THE FAR WESTERN
PIEDMONT.
THE AFOREMENTIONED UPPER TROUGH WILL ROTATE OFFSHORE OF ME BY SAT
AFTERNOON AND RIDGING OVER THE MID-SECTION OF THE COUNTRY WILL
FLATTEN AS IT MOVES EAST INTO OUR AREA SUN MORNING. ANOTHER COOL AND
GUSTY DAY IS EXPECTED ON SAT WITH NW WINDS OF 20-25 MPH. AREAS OF
STRATOCU WILL ALSO BE AROUND IN THE PERSISTENT CYCLONIC FLOW. HIGHS
MID 50S TO AROUND 60. AS SURFACE HIGH PRESSURE BUILDS IN SAT NIGHT,
WINDS FINALLY RELAX, FAVORING OUR BEST SHOT OF WIDESPREAD FROST WITH
LOWS IN THE LOW TO MID 30S.
A MORE OR LESS QUASI-ZONAL FLOW IS DEPICTED IN THE GUIDANCE FROM SUN
THROUGH TUE. AT THE SURFACE, RIDGING OFF THE SOUTHWEST ATLANTIC WILL
PROMOTE LOW-LEVEL WAA RETURN FLOW AND HIGHS REBOUNDING FROM THE
UPPER 50S TO LOW/MID 60S SUN TO WELL ABOVE NORMAL IN THE MID/UPPER
60S TO LOW 70S MON AND TUE. GUIDANCE IS MIXED ON A POTENTIAL
SOUTHWARD PROGRESSION OF A FRONTAL BOUNDARY DRAPED FROM THE MIDWEST
INTO THE OH/TN VALLEYS EARLY TO THE MIDDLE PART OF NEXT WEEK.
COMBINED WITH SOME DISTURBANCES IN THE FLOW COULD FAVOR SOME LIGHT
SHOWERS BY TUE AND PERHAPS COOLER BY WED. MOST ENSEMBLE CLUSTERS,
THOUGH, KEEP ANY PRECIPITATION TO OUR NORTH AND NORTHWEST SO HAVE
KEPT THE FORECAST DRY FOR THE MOMENT.
AVIATION /06Z WEDNESDAY THROUGH SUNDAY/
AS OF 1255 AM WEDNESDAY...
AREAS OF LIGHT RAIN AND SHOWERS WILL CROSS THE REGION THIS MORNING.
THIS WILL LEAD TO VFR CEILINGS LOWERING TO IFR BETWEEN 06Z AND 12Z
IN THE WEST AND CENTRAL PIEDMONT, THEN BETWEEN 10Z AND 14Z IN THE
COASTAL PLAIN. THE LOW CLOUDINESS (IFR) TO POTENTIALLY PERIODS OF
LIFR WILL CONTINUE TODAY, WITH A CHANCE OF ADDITIONAL MVFR
VISIBILITIES IN SCATTERED SHOWERS.
SURFACE WINDS WILL BE LIGHT FROM THE S OR SW, MOSTLY UNDER 10 KTS,
BUT VERY LATE TODAY AND THIS EVENING, AN ABRUPT WIND SHIFT TO THE
WEST THEN NORTHWEST WILL OCCUR AS THE COLD FRONT MOVES THROUGH. IT
APPEARS THAT 23Z-01Z WILL BE THE FRONTAL PASSAGE AT KINT/GSO, THEN
01Z-03Z ELSEWHERE.
LOOKING BEYOND 03Z THU, AS THE COLD FRONT SHIFTS E THROUGH CENTRAL
NC, CEILINGS 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.
RAH WATCHES/WARNINGS/ADVISORIES
NONE.
SYNOPSIS...BADGETT
NEAR TERM...LUCHETTI/CA
SHORT TERM...GREEN
LONG TERM...KREN
AVIATION...BADGETT/HARTFIELD
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