023
FXUS62 KRAH 162117
AFDRAH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
413 PM EST SUN FEB 16 2025
SYNOPSIS
A COLD FRONT MOVING WEST TO EAST THROUGH CENTRAL NORTH CAROLINA THIS
AFTERNOON WILL PUSH OFF THE COAST THIS EVENING. HIGH PRESSURE WILL
BEGIN TO BUILD IN FROM THE NORTHWEST TONIGHT INTO TUESDAY. OUR NEXT
STORM SYSTEM WILL APPROACH FROM THE WEST AND SOUTH TUESDAY NIGHT,
AND MAY BRING SIGNIFICANT WINTRY WEATHER TO PORTIONS OF CENTRAL
NORTH CAROLINA WEDNESDAY INTO EARLY THURSDAY.
NEAR TERM /THROUGH TONIGHT/
AS OF 125 PM SUNDAY...
* WIND ADVISORY REMAINS IN EFFECT FOR ALL OF CENTRAL NC UNTIL 4 PM
THE EARLIER CONVECTIVE LINE HAS MOVED WELL TO OUR E, ALTHOUGH PATCHY
SHOWERS WILL PERSIST AND MOVE THROUGH THE AREA FOR SEVERAL MORE
HOURS AHEAD OF THE COLD FRONT, WHICH IS CURRENTLY ANALYZED JUST W OF
THE CWA. BLUSTERY AND GUSTY WINDS PERSIST OVER THE AREA, FACILITATED
BY 925 MB FLOW THAT IS VEERING AND SLOWLY DECREASING BUT STILL QUITE
ROBUST AT 35-50 KTS, AND GOES DERIVED MEAN WINDS ARE STILL SHOWING
900-770 MB WINDS FROM THE WSW OR W AT 35-50 KTS COMING INTO OUR W
CWA. PARTIAL CLEARING AND A PERIOD OF INSOLATION NEAR AND JUST
BEHIND THE FRONT IS RESULTING IN A BRIEF STEEPENING OF LOW LEVEL
LAPSE RATES, CORROBORATED BY RECENT RAP SOUNDINGS, AND THIS SHOULD
RESULT IN A CONTINUED RISK OF STRONG WIND GUSTS FOR A FEW MORE HOURS
AS THESE WINDS JUST ALOFT MIX GROUNDWARD. WE MAY SEE A FEW GUSTS
APPROACHING 35-40 MPH THROUGH EARLY EVENING, BUT OVERALL THE THREAT
OF WIDESPREAD FREQUENT GUSTS OVER 40 MPH WILL BE DIMINISHING TOWARD
SUNSET, SO CURRENT PLANS ARE TO LET THE WIND ADVISORY EXPIRE ON
SCHEDULE. THE COLD FRONT AND ASSOCIATED MID LEVEL SHEAR AXIS
SWINGING THROUGH THE MEAN TROUGH BASE WILL SHIFT OFFSHORE BY EARLY
THIS EVENING, THUS EXPECT CLEARING SKIES FROM W TO E BY MID EVENING
AS LOWER DEWPOINTS SPREAD INTO THE AREA WITHIN A WNW LOW LEVEL FLOW,
ALTHOUGH THE STEADY STIRRING OVERNIGHT WILL KEEP TEMPS FROM FALLING
TOO FAR. EXPECT LOWS IN THE MID 20S TO LOWER 30S. -GIH
SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/
AS OF 309 PM SUNDAY...
MON/MON NIGHT: BROAD, FAST ZONAL STEERING FLOW WILL PERSIST, AS VAST
SURFACE HIGH PRESSURE CENTERED OVER SASKATCHEWAN SPREADS SE INTO NC.
DRY AND STABLE AIR THROUGH A DEEP LAYER WILL KEEP SKIES FAIR TO
MOSTLY SUNNY MON, ALTHOUGH BY MON NIGHT WELL START TO SEE HIGH
CLOUDS SPREADING IN FROM THE WYOMING BASIN/N ROCKIES AND CENTRAL
PLAINS, ESP ACROSS OUR N, AND SKIES HERE SHOULD TREND TO PARTLY
CLOUDY. LOW LEVEL THICKNESSES WILL BE AROUND 35 M BELOW NORMAL, THUS
EXPECT BELOW NORMAL HIGHS IN THE MID 40S TO LOW 50S, FOLLOWED BY
LOWS IN THE MID 20S TO AROUND 30. -GIH
TUE/TUE NIGHT: THE MID-LEVEL FLOW TUESDAY WILL START OFF ZONAL
BEFORE A WEAKLY AMPLIFIED RIDGE DEVELOPS OVER CENTRAL NC TUESDAY
EVENING. A STRONG HIGH OVER THE UPPER MIDWEST WILL EXTEND COOL NELY
FLOW ACROSS OUR AREA. HIGH CLOUDS AND CHILLY TEMPS IN THE UPPER 40S
TO LOWER 50S IS EXPECTED WITH DRY CONDITIONS. THE MID-LEVEL RIDGE
WILL DE-AMPLIFY AS A STRONG TROUGH DIGS INTO THE UPPER MIDWEST
OVERNIGHT. ANY PRECIPITATION SHOULD GENERALLY HOLD OFF THROUGH 12Z
WEDNESDAY. OVERNIGHT LOWS IN THE UPPER 20S TO LOWER TO MID 30S IS
EXPECTED.
LONG TERM /WEDNESDAY THROUGH SUNDAY/
AS OF 400 PM SUNDAY...
A SOUTHERN STREAM SHORTWAVE WILL MOVE EAST FROM THE SOUTHERN PLAINS
ON TUESDAY NIGHT TO THE DEEP SOUTH ON WEDNESDAY, WHILE A SEPARATE
NORTHERN STREAM CLOSED MID/UPPER LOW DRIFTS SE FROM THE NORTHERN
PLAINS TO THE UPPER GREAT LAKES REGION. THE SOUTHERN WAVE AND UPPER
DIVERGENCE FROM THE RIGHT ENTRANCE REGION OF AN ASSOCIATED UPPER JET
STREAK WILL SPAWN A SURFACE LOW THAT DEVELOPS ON A COLD FRONT ALONG
THE GULF COAST ON TUESDAY NIGHT AND EARLY WEDNESDAY. THIS LOW WILL
THEN DEEPEN AND MOVES NE IN A CLASSIC "MILLER A" TRACK ALONG OR JUST
OFF THE SOUTHEAST US COAST ON WEDNESDAY AFTERNOON AND EVENING. WITH
A COLD DRY AIR MASS IN PLACE AHEAD OF THE SYSTEM, CONFIDENCE IS
INCREASING IN A PERIOD OF FROZEN PRECIPITATION ACROSS MOST OF
CENTRAL NC FROM LATE WEDNESDAY MORNING INTO WEDNESDAY EVENING.
HOWEVER, HOW IMPACTFUL IT IS STILL REMAINS TO BE SEEN, WITH BOTH
PRECIPITATION TYPES AND AMOUNTS WILL VERY MUCH UP IN THE AIR. THIS
DOES NOT LOOK LIKE AN ALL SNOW EVENT, AS THERE IS ALMOST DEFINITELY
GOING TO BE SIGNIFICANT WARMING ALOFT WITH SOUTHERLY FLOW AT 850 MB.
AT THIS TIME, THE MOST LIKELY PART OF THE REGION TO STAY ALL OR
MOSTLY SNOW IS THE FAR NORTHERN PIEDMONT, WITH A FAIRLY LARGE
CORRIDOR OF MAINLY SLEET AND FREEZING RAIN TO THE SOUTH. OUR
SOUTHERN TIER OF COUNTIES INCLUDING FAY ARE MOST LIKELY TO STAY ALL
OR MOSTLY RAIN.
A LOT WILL DEPEND ON THE DEGREE OF PHASING THAT CAN OCCUR BETWEEN
THE SOUTHERN STREAM AND NORTHERN STREAM WAVE, THE LATTER OF WHICH
ALSO HAS AN ASSOCIATED JET STREAK WHICH DIVES INTO THE CENTRAL
PLAINS AND MID-MS VALLEY. THE ECMWF (AND TO SOME DEGREE THE
CANADIAN) HAS A FASTER AND DEEPER NORTHERN STREAM MID/UPPER LOW
COMPARED TO THE GFS, ALLOWING FOR STRONGER HEIGHT FALLS AND GREATER
ENERGY INTERACTION BETWEEN THE TWO SYSTEMS. THIS RESULTS IN A DEEPER
COASTAL LOW AND WOULD BRING A HIGH IMPACT WINTER STORM TO CENTRAL
NC, WITH COLDER TEMPERATURES AND GREATER QPF AMOUNTS. THE GFS WOULD
BE MORE OF A MODERATE/NUISANCE TYPE EVENT THAT ONLY LASTS FOR 6-12
HOURS BEFORE WE ARE QUICKLY DRYSLOTTED AFTER 00Z THURSDAY. THIS IS
BORNE OUT IN THEIR RESPECTIVE ENSEMBLES AS WELL, WITH THE EPS
ENSEMBLES DEPICTING A 50+% PROBABILITY OF WARNING CRITERIA SNOW (>=
3 INCHES) ACROSS ROUGHLY THE NORTHERN HALF OF THE REGION WHILE THE
GEFS ONLY HAVE 20-40% PROBABILITIES THAT ARE CONFINED TO OUR
NORTHERN TIER OF COUNTIES. DETERMINISTIC AND ENSEMBLE GUIDANCE HAS
ALSO BEEN DEPICTING POTENTIAL FOR SIGNIFICANT AMOUNTS OF FREEZING
RAIN SOMEWHERE ACROSS CENTRAL NC, PERHAPS EXCEEDING A QUARTER INCH,
WITH THE GREATEST PROBABILITIES FROM AROUND RALEIGH TO THE SOUTH AND
EAST. THE NAM IS SURPRISINGLY THE WARMEST OUT OF ALL GUIDANCE, WITH
MOSTLY LIQUID FOR A GOOD PART OF THE AREA, BUT CONSIDERING THIS
STORM IS AT THE VERY END OF ITS RANGE, WILL MOSTLY DISREGARD IT AT
THIS TIME.
IT SHOULD BE NOTED THAT NEITHER THE GFS OR ECMWF HAS COMPLETE
PHASING BETWEEN THE TWO WAVES, AND THE OVERALL TREND IN BOTH
DETERMINISTIC AND ENSEMBLE GUIDANCE HAS BEEN SLIGHTLY DOWNWARD IN
TERMS OF OVERALL QPF WITH A FASTER EXIT OF PRECIP, SO WILL NEED TO
SEE IF THIS TREND CONTINUES. YESTERDAY THE ENSEMBLE MEAN QPF WAS IN
THE 1 TO 2 INCH RANGE, WHILE TODAY IT IS MORE LIKE THE 0.5 TO 1.5
INCH RANGE, LOWEST WEST AND HIGHEST EAST. IF THIS TREND CONTINUES,
WE WOULD BE LOOKING AT MORE OF A NUISANCE TYPE EVENT LIKE THE GFS
HAS, BUT THAT IS A BIG IF. STAY TUNED AS DETAILS SHOULD BECOME
CLEARER, HOPEFULLY BY TOMORROW WHEN THE SOUTHERN WAVE REACHES THE
WEST COAST AND WE CAN GET BETTER SAMPLING. AS FOR TIMING,
PRECIPITATION STILL LOOKS TO START FROM SW TO NE ON WEDNESDAY
MORNING, ENDING FROM SW TO NE DURING THE EVENING OR EARLY OVERNIGHT
HOURS. TEMPERATURES WILL BE HIGHLY DEPENDENT ON THE ULTIMATE
EVOLUTION OF THE SYSTEM, BUT WEDNESDAY IS LIKELY TO BE QUITE CHILLY
WITH TEMPERATURES STUCK IN THE LOWER-TO-MID-30S DURING THE DAY,
MAYBE EVEN UPPER-20S IN THE FAR NORTH. FORECAST LOWS WEDNESDAY NIGHT
ARE IN THE UPPER-TEENS TO MID-20S.
THE ARCTIC HIGH WILL BUILD DOWN INTO THE CENTRAL PLAINS AND MID-MS
VALLEY ON THURSDAY NIGHT AND FRIDAY, THEN THE TN VALLEY ON SATURDAY
AND THE EAST COAST ON SUNDAY. THIS WILL BRING A VERY COLD AND DRY
AIR MASS WHICH GRADUALLY MODIFIES THROUGH THE END OF THE PERIOD BUT
STAYS COOLER THAN NORMAL. WITH STRONG NW FLOW AND CAA, HIGHS
THURSDAY WILL AGAIN BE WELL BELOW NORMAL, IN THE 30S, WHILE FORECAST
LOWS THURSDAY NIGHT ARE ONLY IN THE TEENS. FRIDAY'S FORECAST HIGHS
ONLY IN THE UPPER-30S TO LOWER-40S, THEN LOWER-TO-MID-40S ON
SATURDAY, AND MID-TO-UPPER-40S ON SUNDAY. A SHORTWAVE TROUGH LOOKS
TO MOVE ACROSS THE LOWER-MS VALLEY AND DEEP SOUTH ON SATURDAY NIGHT
AND SUNDAY, BUT THE VAST MAJORITY OF ENSEMBLE MEMBERS KEEP
ASSOCIATED MOISTURE SUPPRESSED TO OUR SOUTH, SO ONLY HAVE SLIGHT
CHANCE POPS IN THE FAR SE.
AVIATION /18Z SUNDAY THROUGH FRIDAY/
AS OF 1250 PM SUNDAY...
PRIMARY AVIATION CONCERN FOR THE NEXT 6-9 HOURS REMAINS THE STRONG
GUSTY SURFACE WINDS, FROM THE SW SHIFTING TO WNW, ALONG WITH A FEW
MORE HOURS OF LOW LEVEL WIND SHEAR POTENTIAL, ESPECIALLY AT EASTERN
TERMINALS, WITH 2KFT WINDS FROM THE SW AT 45-60 KTS. CROSSWINDS MAY
REMAIN AN ISSUE THROUGH THIS AFTERNOON AT RUNWAYS RUNNING NW TO SE.
THESE STRONG WINDS ALOFT WILL EXIT TO THE E OF THE AREA BY 00Z, AND
SURFACE WINDS WILL GRADUALLY LESSEN FROM 21Z TO 06Z, WITH GUSTS
EXPECTED TO BE LARGELY DIMINISHED BY 06Z-08Z. SURFACE WINDS WILL BE
FROM THE NW LATE TONIGHT THROUGH MON AT 8-14 KTS. STEADY SHOWERS
PERSIST AT THIS HOUR IN THE EXTREME E (RWI) WITH MORE PATCHY SHOWERS
OVER THE REST OF CENTRAL NC; THESE SHOWERS WILL END FOR GOOD FROM W
TO E 20Z-00Z AS A COLD FRONT SWEEPS THROUGH. LINGERING AREAS OF MVFR
CIGS, INCLUDING AT AND NEAR INT/GSO/RDU, WILL YIELD TO CLEARING
SKIES, AND EXPECT VFR CONDITIONS AREAWIDE AFTER 00Z.
LOOKING BEYOND 18Z MON, VFR CONDITIONS WILL PREVAIL THROUGH TUE
EVENING AS HIGH PRESSURE EXTENDS IN FROM THE NW. STARTING LATE TUE
NIGHT AND LASTING THROUGH EARLY THU, A STORM SYSTEM WILL BRING HIGH
CHANCES FOR SUB-IFR CONDITIONS AND SIGNIFICANT WINTRY WEATHER TO
MUCH OF CENTRAL NC, INCLUDING A RISK FOR ICE AND SNOW. VFR
CONDITIONS ARE EXPECTED TO RETURN THU AND FRI, ALTHOUGH GUSTY WINDS
FROM THE NW ARE LIKELY THU. -GIH
RAH WATCHES/WARNINGS/ADVISORIES
NONE.
SYNOPSIS...HARTFIELD
NEAR TERM...HARTFIELD
SHORT TERM...HARTFIELD/LUCHETTI
LONG TERM...DANCO
AVIATION...HARTFIELD
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