560
FXUS62 KRAH 182346
AFDRAH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
645 PM EST MON NOV 18 2024
SYNOPSIS
HIGH PRESSURE CENTERED OFFSHORE WILL EXTEND OVER THE SOUTHEAST COAST
THROUGH TUESDAY. AN UPPER LEVEL DISTURBANCE WILL PASS THROUGH THE
CAROLINAS EARLY WEDNESDAY. A SURFACE COLD FRONT WILL CROSS THE AREA
WEDNESDAY NIGHT, USHERING IN COOLER AIR FOR LATE WEEK.
NEAR TERM /THROUGH TONIGHT/
AS OF 250 PM MONDAY...
THIS AFTERNOON: DOWNSTREAM OF THE VIGOROUS, NEGATIVELY TILTED
SHORTWAVE TROUGH EJECTING NORTHEASTWARD THROUGH THE CENTRAL PLAINS,
STRONG SUB-TROPICAL HIGH PRESSURE WILL PREVAIL OVER THE SE US
THROUGH EARLY TUESDAY. INTERVALS OF CIRRUS WILL CONTINUE TO SPILL
ATOP THE RIDGE, ESPECIALLY ACROSS THE NORTHERN HALF OF THE FORECAST
AREA. UNDER PARTLY TO MOSTLY SUNNY SKIES HIGHS TODAY A FEW DEGREES
WARMER THAN YESTERDAY, WITH MOST PLACES WARMING INTO THE UPPER 60S
TO LOWER 70S, WHICH IS 5-10 DEGREES ABOVE THE 30 YR NORMS.
TONIGHT: WITH EXPECTATIONS OF THE CIRRUS CLOUD COVER BEING MORE MORE
PERVASIVE AND OPAQUE ACROSS NORTHERN AND CENTRAL NC, THE BEST
CHANCE/HIGH PROBABILITIES FOR FOG ARE LINING ACROSS SOUTHERN PORTIONS
OF THE FORECAST AREA. MILD OVERNIGHT LOWS IN THE MID 40S TO LOWER
50S, WHICH IS 8 TO 15 DEGREES ABOVE NORMAL.
SHORT TERM /TUESDAY AND TUESDAY NIGHT/
AS OF 247 PM MONDAY...
THE UPPER AND SFC RIDGE AXIS WILL GRADUALLY MOVE EAST AND OFFSHORE
THROUGH THE DAY. SUBSEQUENT SW FLOW ON THE BACK SIDE OF THE RIDGE
WILL RESULT IN INCREASING MID AND HIGH CLOUDINESS ACROSS OUR AREA AS
THE DAY PROGRESSES, BUT ESP IN THE LOWER LEVELS LATER IN THE
AFTERNOON AND EVENING PER LATEST FORECAST SOUNDINGS FOR LOCATIONS
ACROSS OUR AREA. WITH AN AIRMASS SIMILAR TO TODAY, AND FILTERED
SUNSHINE, LOOK FOR HIGHS TUESDAY AFTERNOON WITHIN A COUPLE DEGREES
OF TODAY'S HIGHS.
AS THE UPPER TROUGH CONTINUES TO APPROACH TUESDAY NIGHT, INCREASED
FLOW AND WAA FROM THE SFC UP TO 5K FT, AND RESULTING LIFT IN THE LOW
LEVELS, WILL WARRANT GRADUALLY INCREASING POPS FROM SUNSET TUESDAY
ONWARD, BUT ESP AFTER MIDNIGHT AS THE WAA IS MAXIMIZED. LOWS
TUESDAY NIGHT WILL BE ABOUT 5-10 DEG WARMER THAN TONIGHT GIVEN
INCREASED CLOUD COVER AND WAA... MID 50S ACROSS MUCH OF CENTRAL NC.
LONG TERM /WEDNESDAY THROUGH MONDAY/
AS OF 339 PM MONDAY...
WEDNESDAY: LATEST GUIDANCE FOR WEDNESDAY SUGGESTS THAT THE
COMBINATION OF LIFT, MOISTURE, AND INSTABILITY (MEAGER AT BEST) MAY
NOT COINCIDE ENOUGH TO PRODUCE MUCH OF A THUNDERSTORM THREAT. LATEST
GUIDANCE SUGGESTS THE STRONGEST HEIGHT FALLS WILL LIKELY LAG BEHIND
THE DEPARTURE OF THE DEEPEST MOISTURE. SO WHILE WE'LL BE FIRMLY IN
THE WARM SECTOR WEDNESDAY AFTERNOON (WITH DEW POINTS IN THE LOWER TO
MID 60S), IT APPEARS THAT A LACK OF LIFT AND DESTABILIZATION WILL
LIKELY LIMIT COVERAGE. CAMS ARE IN GENERAL AGREEMENT WITH THIS
SCENARIO, SIMULATING SHOWERS EARLY WEDNESDAY MORNING (WITH HIGHEST
POPS IN THE SOUTH), FOLLOWED BY ISOLATED SHOWERS IN THE AFTERNOON.
AFTER THE MORNING SHOWERS MOVE EAST OF OUR AREA, ADDITIONAL ISOLATED
SHOWERS (AND PERHAPS A FEW THUNDERSTORMS) WILL BE POSSIBLE WEDNESDAY
AFTERNOON AND EVENING AHEAD OF THE COLD FRONT WHICH WILL PASS
THROUGH LATE WEDNESDAY NIGHT. IF AN ISOLATED STORM CAN DEVELOP
WEDNESDAY AFTERNOON, THERE IS A NON-ZERO CHANCE FOR AN ISOLATED
DAMAGING WIND GUST GIVEN HOW STRONG THE SHEAR WILL BE. BUT AGAIN,
THINK THIS IS UNLIKELY AT THIS POINT.
THURSDAY THROUGH MONDAY: PERSISTENT NWLY FLOW WITH STRONG CAA IS
EXPECTED BEHIND THE EXITING UPPER TROUGH (AS THE UPPER LOW MOVES
OVERHEAD THURSDAY NIGHT INTO SATURDAY). AS SUCH, A DRASTIC
TEMPERATURE CHANGE IS EXPECTED FROM HIGHS IN THE UPPER 60S/LOWER 70S
WEDNESDAY TO HIGHS STRUGGLING TO REACH THE LOWER TO MID 50S THURSDAY
THROUGH SUNDAY. THE RAW NBM IS ALSO ALREADY SUGGESTING THE POTENTIAL
FOR SOME QUITE COLD NIGHTS PARTICULARLY THIS UPCOMING WEEKEND. WE
COULD SEE OVERNIGHT LOWS DIP NEAR FREEZING FOR A GOOD PORTION OF OUR
AREA. TEMPERATURES WILL MODERATE BACK INTO THE UPPER 50S/LOWER 60S
ON MONDAY.
DRY CONDITIONS ARE GENERALLY EXPECTED FROM THURSDAY THROUGH MONDAY.
HOWEVER, SOME LINGERING MOISTURE, COMBINED WITH STEEP MID-LEVEL
LAPSE RATES, MAY PROMOTE SPRINKLES (AND PERHAPS ISOLATED GRAUPEL
REPORTS) THURSDAY AND FRIDAY.
LASTLY, GUSTY SFC WINDS ARE STILL EXPECTED THURSDAY AND FRIDAY,
LINGERING A BIT INTO SATURDAY. GUSTS OF 25 TO 35 MPH WILL BE
POSSIBLE DURING THIS PERIOD.
AVIATION /00Z TUESDAY THROUGH SATURDAY/
AS OF 645 PM MONDAY...
WE'LL CONTINUE TO SEE MOSTLY HIGH CLOUDS ABOVE 18,000 FT AGL STREAM
OVER THE AREA THROUGH DAYBREAK TUE, THICKEST OVER NORTHERN
TERMINALS, HOWEVER THERE IS A RISK OF PATCHY MVFR-IFR VSBYS IN THE
FAR S AREAS 08Z-12Z, AND THESE MAY BRING BRIEF SUB-VFR CONDITIONS TO
FAY LATE TONIGHT. AROUND MID MORNING (14Z-16Z), A SHORT PERIOD OF
SCT-BKN MVFR CLOUDS IS POSSIBLE AREAWIDE, BUT THESE WILL BE SHORT-
LIVED. VFR CONDITIONS ARE THEN EXPECTED TO DOMINATE FROM LATE
MORNING THROUGH SUNSET TUE, ALTHOUGH HIGH CLOUDS WILL STEADILY LOWER
DOWN TO MID LEVEL CIGS THROUGH THE DAY. SURFACE WINDS WILL BE NEAR
CALM THROUGH MID MORNING TUE, THEN FROM THE SW AT 5-8 KTS.
LOOKING BEYOND 00Z WED, AHEAD OF AN APPROACHING UPPER LEVEL
DISTURBANCE AND SURFACE FRONT, CIGS ARE EXPECTED TO LOWER TO SUB-VFR
FROM W TO E STARTING EARLY TUE EVENING (SHORTLY AFTER 00Z), AND
EVERYONE IS LIKELY TO HAVE SUB-VFR CIGS/VSBYS BY 10Z WED. RAIN
CHANCES WILL ARRIVE OVERNIGHT, MOVING W TO E AND LASTING UNTIL ABOUT
MID MORNING WED. WE SHOULD HAVE A LULL IN RAIN CHANCES FROM MID
MORNING THROUGH LATE AFTERNOON, BUT SUB-VFR CIGS SHOULD HOLD.
ANOTHER ANOTHER ROUND OF SHOWERS AND PERHAPS A THUNDERSTORM OR TWO
ARE POSSIBLE LATE WEDNESDAY AFTERNOON THROUGH EVENING, WITH SUB-VFR
CONDITIONS PERSISTING. BEHIND THE SURFACE COLD FRONT, FREQUENT GUSTS
OF 20-30 KTS ARE EXPECTED BOTH THU AND FRI. -GIH
RAH WATCHES/WARNINGS/ADVISORIES
NONE.
SYNOPSIS...HARTFIELD
NEAR TERM...CBL
SHORT TERM...NP
LONG TERM...LUCHETTI
AVIATION...HARTFIELD/CBL
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