896
FXUS62 KRAH 201748
AFDRAH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
1245 PM 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 1135 AM WEDNESDAY...
FOR THE NEAR TERM UPDATE THIS MORNING, HAVE ADJUSTED POPS FOR
THE PROPAGATION OF A MAIN AREA OF SHOWERS PUSHING EASTWARD ACROSS
THE SOUTHEASTERN HALF OF THE CWA ASSOCIATED WITH A DISTURBANCE
AHEAD OF THE SFC COLD FRONT. THIS FRONT STILL LOOKS TO
POTENTIALLY ENHANCE SOME THINNER SHOWER REGENERATION AS THE
FRONT PASSES MAINLY FROM 00Z-06Z THIS EVENING. SO FAR THE
ACTIVITY LOOKS TO HAVE DROPPED ABOUT 0.25-0.50 INCHES OF GOOD
WETTING RAIN TOTALS. ALSO DID SOME TEMP/DEWPT ADJUSTMENTS PER
RECENT GUIDANCE. PREVIOUS DISCUSSION FOLLOWS...
BAKER
AS OF 321 AM WEDNESDAY...
OVERCAST AND SHOWERY TODAY, TURNING SHARPLY COLDER AND BREEZY
TONIGHT.
THE LATEST RADAR AND DATA ANALYSIS INDICATE SHOWERS INCREASING FROM
NORTH GA NORTHEAST INTO THE WESTERN CAROLINA'S. MOST OF THE RAIN IS
LIGHT WITH A FEW POCKETS OF MODERATE RAINFALL. THESE SHOWERS ARE
ASSOCIATED WITH THE PRE-FRONTAL TROUGH AND UPPER LEVEL DISTURBANCE.
THE LATEST MODELS SUGGEST THAT THE SHOWERS WILL CONTINUE TO MOVE NE
AND AFFECT MUCH OF THE WESTERN AND NORTHERN SECTIONS FIRST THING
THIS MORNING. THE ACTIVITY IS THEN EXPECTED TO FOCUS OVER SOUTHERN
AND EASTERN AREAS LATE MORNING INTO THE AFTERNOON. QPF AROUND 0.1 TO
0.25 IS LIKELY BEFORE 12Z IN THE WEST, WITH AMOUNTS AROUND .1 TO
POSSIBLY 0.25 IN THE SOUTH AND EAST AFTER 12Z. THUS, FAIRLY HIGH POP
WITH LOW QPF. HIGHS IN THE MID TO UPPER 60S, POSSIBLY SOME LOWER 70S
SE BEFORE THE SHOWERS. A LOW OVERCAST OF STRATUS IS EXPECTED TO
PERSIST THROUGH THE AFTERNOON KEEPING TEMPERATURES DOWN A BIT.
THE STRONG COLD FRONT IS EXPECTED TO ARRIVE THIS EVENING, BY AROUND
23Z-01Z IN THE TRIAD, 00Z-02Z OR SO IN THE TRIANGLE, AND AROUND 02Z-
04Z IN THE SE. THERE MAY STILL BE A NARROW BAND OF LOW TOPPED
SHOWERS WITH THE FRONT, FAVORING THE NORTH AND NORTHEAST. WINDS WILL
BECOME WNW AT 15-25 MPH FOR A PERIOD AFTER THE FRONTAL PASSAGE.
GUSTS TO 35 MPH ARE POSSIBLE IN THE TRIAD AND 30 MPH ELSEWHERE.
WINDS WILL WEAKEN A BIT OVERNIGHT TO AROUND 10-15 MPH. THIS STRONG
CAA WILL DRIVE TEMPERATURES INTO THE MID 30S NORTH AND WEST RANGING
INTO THE 40-45 RANGE SE. SKIES WILL BECOME MOSTLY CLEAR TO PARTLY
CLOUDY TONIGHT.
SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/
AS OF 445 AM WEDNESDAY...
WE WILL NOT GO WITH A FREEZE WATCH YET. WE WILL LET THE DAY SHIFT
ANALYZE THE NEW DATA BEFORE TRYING TO PIN DOWN THE EXACT LOCATIONS.
STRONG CAA WILL CONTINUE THURSDAY. IN ADDITION, CLOUDINESS WILL
INCREASE AGAIN DURING THE LATE MORNING AND AFTERNOON AS THE SURFACE
HEATS AND THE MID/UPPER LEVELS CONTINUE TO COOL WITH THE LOWERING
HEIGHTS ALOFT. WEST WINDS WILL BECOME WINDY AFTER MIXING BEINGS
AROUND MID-MORNING. EXPECT 15-25 MPH WITH GUSTS TO 30 MPH. HIGHS
WILL LIKELY RANGE FROM AROUND 50 NW TO NEAR 60 SE.
WE ARE A BIT HESITANT IN ISSUING A FREEZE WATCH AT THIS TIME. THERE
ARE MIXED SIGNALS FOR THE POTENTIAL FOR FREEZING CONDITIONS THURSDAY
NIGHT. SOME CLOUDINESS IS EXPECTED TO CONTINUE WITH THE NW FLOW AND
COLD AIR ALOFT. LOWS WILL DEPEND ON HOW MUCH CLOUDINESS CONTINUES.
IN ADDITION, SOME MIXING WILL CONTINUE WITH A LIGHT WEST WIND. THIS
WILL LIKELY PLAY A ROLE IN LOW TEMPERATURES, ESPECIALLY CLOSER TO
THE MOUNTAINS AROUND THE NW PIEDMONT TRIAD. EXPECT LOWER TO MID 30S
FOR LOWS WITH VARIABLY CLOUDY SKIES. IF THE SKIES ARE EXPECTED TO
CLEAR FOR A SUBSTANTIAL TIME IN LATER FORECASTS, A FREEZE WARNING OR
FROST ADVISORY WILL BE NEEDED.
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 /18Z WEDNESDAY THROUGH MONDAY/
AS OF 1245 PM WEDNESDAY...
TAF PERIOD: AN AREA OF RAIN HAS MOVED THROUGH MUCH OF THE REGION,
WITH IFR/LIFR CONDITIONS AT ALL SITES. AN ANOTHER AREA OF RAIN COULD
FILL BACK INTO THE AREA DURING THE LATE AFTERNOON AND EVENING HOURS.
A COLD FRONT WILL MOVE THROUGH DURING THE EVENING, BRINGING DRIER
AIR (MIXING OUT THE LOW CEILINGS) AS WELL AS GUSTY WINDS. HAVE GONE
WITH 25-30 KT WINDS IN THE TAFS, BUT SOME MODEL GUIDANCE IS
INDICATING THAT GUSTS ALONG THE FRONT COULD BE IN THE 30-40 KT
RANGE, AND THIS WILL REQUIRE FURTHER INVESTIGATION. AFTER A 3-6 HR
WINDOW, IT APPEARS THAT ALL SITES SHOULD HAVE GUSTS COME TO AN END
DURING THE OVERNIGHT PERIOD WITH CLEARING SKIES. AFTER SUNRISE,
DAYTIME MIXING SHOULD ALLOW FOR ANOTHER ROUND OF GUSTS, ALTHOUGH
THURSDAY'S GUSTS SHOULD NOT BE NEARLY AS STRONG AS THE OVERNIGHT
WINDS, CLOSER TO 20 KT WIND. SOME HIGHER CLOUDS WILL LIKELY MOVE
INTO THE TRIAD LATE THURSDAY MORNING, ALTHOUGH THESE WILL NOT BRING
ANY FLIGHT RESTRICTIONS.
OUTLOOK: NO PRECIPITATION IS IN THE FORECAST DURING THE OUTLOOK
PERIOD WITH VFR CONDITIONS. FRIDAY AND SATURDAY WILL HAVE GUSTS TO
25 KT.
RAH WATCHES/WARNINGS/ADVISORIES
NONE.
SYNOPSIS...BADGETT
NEAR TERM...BADGETT/BAKER
SHORT TERM...BADGETT
LONG TERM...KREN
AVIATION...GREEN
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