714
FXUS62 KRAH 190234
AFDRAH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
930 PM EST TUE FEB 18 2025
SYNOPSIS
HIGH PRESSURE WILL BUILD ACROSS VA AND NC TONIGHT. LOW PRESSURE WILL
TRACK ACROSS THE GULF AND SOUTH ATLANTIC COASTS WEDNESDAY AND
WEDNESDAY NIGHT. ARCTIC HIGH PRESSURE WILL FOLLOW AND MIGRATE FROM
THE NORTHERN PLAINS TO THE MIDDLE ATLANTIC, WHILE WEAKENING AND
MODIFYING, THROUGH THE WEEKEND.
NEAR TERM /THROUGH TONIGHT/
AS OF 930 PM TUESDAY...
THIS EVENINGS SURFACE ANALYSIS SHOWS THE FRONTAL BOUNDARY THAT WAS
STRETCHED OVER THE APPALACHIAN MOUNTAINS THEN OVER VA AND NC BORDER
HAS SAGGED SOUTH, GENERALLY STALLING OUT OVER THE WESTERN PORTIONS
OF NC AND LINGERING ALONG THE EASTERN NC/SC BORDER. WITH THAT, NO
MAJOR CHANGES WERE NEEDED WITH THE EVENING UPDATE. UPDATED POPS A
TAD, WITH LATEST MODEL GUIDANCE, SPECIFICALLY SLOWLY DOWN THE
ARRIVAL OF EXPECTED PRECIP (SNOW) A COUPLE HOURS ACROSS THE NW
PIEDMONT. WHILE POPS WILL JUMP TO CHANCE POPS AROUND 7AM FOR MUCH OF
THE NORTHERN PIEDMONT, PRECIP MIGHT NOT BE ABLE TO MAKE IT ALL THE
WAY TO THE SURFACE AS LOW/MID LEVEL POCKETS ARE VERY DRY. BY
MID/LATE MORNING EXPECT TO SEE INCREASED RATES, ALONG WITH SOME
ACCUMULATIONS BEGINNING ACROSS THE REGION. TEMPERATURES OVERNIGHT
WILL DROP INTO THE MID 20S NEAR THE VA//NC BORDER WITH THE REST OF
THE AREA IN THE UPPER 20S TO LOW 30S.
SHORT TERM /WEDNESDAY THROUGH THURSDAY/
AS OF 335 PM TUESDAY...
* NO CHANGE IN THE WINTER STORM WARNING AND ADVISORY AREAS FOR
WEDNESDAY INTO THURSDAY MORNING WITH THE AFTERNOON FORECAST UPDATE
DUE TO LOWER THAN NORMAL FORECAST CONFIDENCE.
* GREATEST TRAVEL IMPACTS AND POTENTIAL POWER OUTAGES WILL MOST
LIKELY OCCUR WEDNESDAY AFTERNOON INTO THE EARLY OVERNIGHT PERIOD.
* LINGERING SNOW SHOWERS THURSDAY MORNING WILL MOVE EAST AHEAD OF A
COLD FRONT WITH BREEZY WIND GUSTS OF 25 TO 35 MPH IN ITS WAKE.
THE OVERALL PATTERN CONSISTS OF A BACKDOOR COLD FRONT AND RESURGENCE
OF COLD/DRY ARCTIC AIR AHEAD THE ONSET OF WINTRY PRECIPITATION WED.
LIGHT PRECIPITATION WILL LIKELY BEGIN TO FALL AROUND 10 AM TOWARDS
THE SC/NC BORDER AND WILL RAPIDLY FILL ACROSS THE AREA INTO THE
EARLY AFTERNOON AS MID/UPPER FORCING FROM THE STRENGTHENING JET
STREAK MOVES OVERHEAD. THE BEST OVERLAP OF SYNOPTIC FORCING AND
INCREASING PRECIPITATION RATES WILL BE OVER THE EASTERN PIEDMONT AND
COASTAL PLAIN WED AFTERNOON TO AROUND 10 PM.
GIVEN THE LACK OF A FAVORABLE AND ANCHORED SURFACE HIGH LOCATION,
THE PREEXISTING ENVIRONMENT DEPOSITED BY THE BACKDOOR FRONT WILL
LIKELY DRIVE THE INITIAL ONSET P-TYPE DISTRIBUTION. CURRENT FORECAST
HIGHLIGHTS A VERY BROAD TRANSITION ZONE CENTERED AROUND US-64 WHERE
SNOW, SLEET, FREEZING RAIN/OR RAIN, WITH PREDOMINANTLY SNOW NORTH OF
THIS ZONE AND INITIALLY LIGHT RAIN TO ITS SOUTH. AS PRECIP RATES
INCREASE THROUGH THE AFTERNOON, SURFACE TEMPERATURES ARE EXPECTED TO
DROP BELOW FREEZING TOWARDS THE SURFACE WETBULB AND RESULT IN AN
EXPANDING AREA OF FREEZING RAIN OVER THE SANDHILLS AND INTO THE
SOUTHERN/CENTRAL COASTAL PLAIN. AT THE SAME TIME, STRENGTHENING
SOUTHERLY WAA ALOFT WILL BEGIN TO LIFT THIS TRANSITION ZONE FARTHER
NORTH, BUT WHERE ITS STALLS IS VERY UNCERTAIN. LATEST FORECAST
TRENDED TOWARDS WARMER/STRONGER WAA SOLUTIONS THAT TYPICALLY VERIFY
CLOSER WELL IN THESE SCENARIOS. THIS BRINGS THE SNOW/SLEET LINE TO
AROUND THE I-85 CORRIDOR INTO THE NORTHERN COASTAL PLAIN BEFORE
COLLAPSING BACK SOUTH OVERNIGHT.
OVERALL PRECIP DISTRIBUTION WILL BEGIN TO SPREAD EASTWARD AND
DECREASE IN INTENSITY AS DRY AIR ALOFT BEGINS TO SPREAD OVERHEAD
LATE WED INTO EARLY THURS. VERY LIGHT FREEZING DRIZZLE AND SPORADIC
SLEET WILL LIKELY BE THE PREDOMINANT P-TYPES DURING THIS TIME AS WE
LOSE SATURATION IN THE DGZ. SNOW ACCUMULATIONS WILL LIKELY BE
GREATEST NORTH OF US-64 AND RANGE FROM 1 TO 5 INCHES, LOCALLY HIGHER
AMOUNTS POSSIBLE TOWARDS THE VA/NC BORDER. ICE ACCUMULATIONS WILL BE
GREATEST SOUTH OF US-64 IN THE COASTAL PLAIN WITH TOTALS RANGING
FROM 0.05" TO AROUND 0.25". A COMBINATION OF SNOW, SLEET, AND
FREEZING RAIN IN THE ADVISORY AREAS MAY RESULT IN MINOR IMPACTS TO
TRAVEL AND WARRANT THE CONTINUATION OF THE ADVISORY AT THIS TIME.
A BRIEF LULL EARLY THURS MORNING WILL FILL BACK IN TOWARDS SUNRISE
AS A POTENT UPPER LOW AND STRONG FORCING OVERSPREADS THE AREA
THROUGH EARLY AFTERNOON. POINT SOUNDINGS SUGGEST STEEPENING LAPSE
RATES AND SATURATION RETURNING TO THE DGZ TO RESULT IN THE POTENTIAL
FOR SCATTERED SNOW SHOWERS. OVERALL ACCUMULATIONS ARE LIGHT AND
MINIMAL TO NO ACCUMULATIONS ARE EXPECTED. THURS AFTERNOON A STRONG
COLD FRONT WILL BEGIN TO MOVE ACROSS THE REGION FROM WEST TO EAST
AND RESULT IN STRONG WIND GUSTS OF 25 TO 35 MPH BEFORE DIMINISHING A
FEW HOURS AFTER SUNSET, ALTHOUGH CONTINUED CAA MAY CONTINUE SOME
GUSTINESS THROUGH THE EVENING.
LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/
AS OF 330 PM TUESDAY...
- VERY COLD CONDITIONS THURSDAY AND FRIDAY NIGHTS FOLLOWED BY DRY
WEATHER AND A WARMING TREND INTO NEXT WEEK.
IN THE WAKE OF THE DEPARTING THE SNOWSTORM COLD ADVECTION WILL
CONTINUE INTO THURSDAY NIGHT. THICKNESSES ARE FORECAST TO DROP TO
NEAR 1260M BY FRIDAY MORNING. OVERNIGHT LOWS DROPPING INTO THE UPPER
TEENS TO LOWER 20S, ALONG WITH A STEADY 10 MPH WIND, WILL CAUSE WIND
CHILLS IN THE LOWER TEENS AND PERHAPS SOME SINGLE DIGITS. A CHILLY
BUT QUIET DAY IS EXPECTED ON FRIDAY, FOLLOWED BY CALM CONDITIONS
FRIDAY NIGHT. THIS WOULD NORMALLY RESULT IN COLDER OVERNIGHT LOWS
FRIDAY NIGHT GIVEN THE AIR MASS CHANGE, BUT MODELS SUGGEST SOME
CIRRUS OVERNIGHT IN RESPONSE TO A SHORTWAVE DIVING THROUGH THE MID
SOUTH, WHICH LOWERS CONFIDENCE IN COLDER OVERNIGHT LOWS.
NONETHELESS, IT SHOULD BE NOTED THAT THERE WILL BE A COUPLE FRIGID
NIGHTS.
A MODERATING TREND THEN BEGINS THROUGH THE WEEKEND INTO EARLY NEXT
WEEK, DESPITE CONTINUED BROAD MEAN TROUGHING ACROSS THE EASTERN US.
A COUPLE OF LOW AMPLITUDE SHORT WAVES ARE FORECAST TO MOVE THROUGH
THE TROUGH AND CROSS NC, AND SOME INDIVIDUAL GUIDANCE SUGGESTING
ENOUGH FORCING FOR SOME LIGHT PRECIP SATURDAY NIGHT AND AGAIN
TUE/TUE NIGHT. THIS IS NOT SUPPORTED BY A MAJORITY OF ENSEMBLE
MEMBERS AND SO WE WILL KEEP THE FORECAST DRY FOR NOW. HIGH
TEMPERATURES CLIMB EACH DAY AND REACH NEAR TO SLIGHTLY ABOVE NORMAL
BY THE MIDDLE OF NEXT WEEK.
AVIATION /00Z WEDNESDAY THROUGH SUNDAY/
AS OF 751 PM TUESDAY...
WHILE CONDITIONS FOR THE TAF PERIOD WILL START AS VFR, CONDITIONS
WILL DETERIORATE TO MVFR AND POTENTIALLY IFR WEDNESDAY MORNING TO
AFTERNOON FOR THE REST OF THE TAF PERIOD. THE FIRST FLIGHT HAZARD,
WHILE VFR, WILL BE WIND GUSTS LATE TONIGHT/EARLY MORNING AS WINDS
STRENGTHEN AND TURN TO THE NORTHEAST BEFORE THE ONSET OF
PRECIPITATION.
WITH RESPECT TO PRECIPITATION, ALL TYPES OF PRECIPITATION ARE
POSSIBLE OVER CENTRAL NC. AT INT/GSO THE PRIMARY PRECIPITATION TYPE
SHOULD BE SNOW, RDU/RWI SHOULD HAVE A MIX OF SNOW AND SLEET, AND FAY
SHOULD HAVE PRIMARILY FREEZING RAIN, WITH THE POTENTIAL FOR A MIX
WITH SLEET DURING THE AFTERNOON. THE HIGHEST PRECIPITATION RATES
SHOULD COME IN THE MID AFTERNOON TO EARLY EVENING AT ALL SITES. MVFR
FLIGHT RESTRICTIONS SHOULD COME IN THE FORM OF REDUCED VISIBILITIES
AND LOW CEILINGS AROUND 1000-2000 FT. IFR CONDITIONS ARE POSSIBLE AT
ALL SITES FROM CEILINGS BRIEFLY LOWERING AND REDUCTIONS IN
VISIBILITIES. NEAR THE END OF THE TAF PERIOD, ANY FROZEN
PRECIPITATION HAS THE POTENTIAL OF TRANSITIONING TO FREEZING RAIN AS
THE UPPER LEVELS DRY OUT, REMOVING ICE FROM THE CLOUDS.
OUTLOOK: MVFR/POTENTIAL IFR CONDITIONS SHOULD CONTINUE OVERNIGHT
WEDNESDAY. A SHORT PERIOD OF LIGHT SNOW IS POSSIBLE ACROSS ALL
TERMINALS THU MORNING BEFORE PRECIPITATION ENDS MIDDAY THU. VFR
RETURNS THU AFTERNOON AND CONTINUES THROUGH THE REMAINDER OF THE
PERIOD.
RAH WATCHES/WARNINGS/ADVISORIES
WINTER STORM WARNING FROM 7 AM WEDNESDAY TO 10 AM EST THURSDAY FOR
NCZ007>011-026>028-043-078.
WINTER WEATHER ADVISORY FROM 7 AM WEDNESDAY TO 10 AM EST THURSDAY
FOR NCZ021>025-038>042-073>077-083>086-088-089.
SYNOPSIS...MWS
NEAR TERM...CA
SHORT TERM...SWIGGETT
LONG TERM...BLS
AVIATION...HELOCK/KREN
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