464
FXUS62 KRAH 180551
AFDRAH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
1250 AM EST FRI JAN 17 2025
SYNOPSIS
MILDER AIR WILL CONTINUE OVER THE REGION INTO SUNDAY. HOWEVER, A
STRONG ARCTIC COLD FRONT WILL CROSS THE AREA FROM THE WEST SUNDAY.
ARCTIC HIGH PRESSURE WILL THEN BRING BITTERLY COLD AIR INTO THE
REGION THROUGH THE MIDDLE OF NEXT WEEK.
NEAR TERM /THROUGH TONIGHT/
AS OF 928 PM FRIDAY...
CLOUDS ARE BEGINNING TO INCREASE FROM THE WEST AHEAD OF OUR MID-
LEVEL SYSTEM APPROACHING FROM THE SOUTHERN PLAINS. THIS SYSTEM IS
FORECAST IN THE MODELS TO REACH THE LOWER OH VALLEY BY 12Z SAT. AT
THE SURFACE, THE CURRENT ANALYSIS REVEALS HIGH PRESSURE OFF THE NC
COAST, WITH AN ARCTIC COLD FRONT DRAPED NE TO SW OVER THE MID MS
VALLEY. A SURFACE LOW WAS ALSO PRESENT ACROSS OKLAHOMA. THE 00Z GSO
SOUNDING SHOWED CONSIDERABLE DRY AIR THROUGHOUT MOST OF THE COLUMN.
AS THE MID-LEVEL SYSTEM TRACKS TO THE EAST AND NORTHEAST, HEIGHT
FALLS AND LIFT FROM THE LEFT-EXIT REGION OF A JET WILL OVERSPREAD
OUR REGION. WAA IN THE LOW TO MID-LEVELS WILL REACH OUR WESTERN
ZONES TOWARD THE EARLY MORNING HOURS AND MUCH OF THE AREA BY
DAYBREAK. THIS SHOULD FAVOR THE DEVELOPMENT OF SCATTERED LIGHT RAIN,
WITH THE HIGHEST CHANCES ACROSS THE NORTHWEST PIEDMONT. TEMPERATURES
ACROSS THE AREA ARE CURRENTLY RANGING FROM THE UPPER 30S TO LOW 40S,
WITH POCKETS OF LOW/MID 30S OVER THE NORTHEAST PIEDMONT AND NORTHERN
COASTAL PLAIN WHERE SKIES ARE STILL CLEAR. WE SHOULD SEE
TEMPERATURES BOTTOM OUT IN THE LOW/MID 30S, WITH A FEW UPPER 20S IN
OUR NE, THEN GRADUALLY RISE AFTER MIDNIGHT WITH DENSE OVERCAST
TAKING OVER. THERE STILL IS A NON-ZERO CHANCE A WINTRY MIX COULD
DEVELOP OVER THE FAR NORTHWEST PIEDMONT EARLY SAT. THIS WOULD APPEAR
RELATED TO SOME INITIAL SUB-FREEZING WET-BULB TEMPS ALOFT, PRIOR TO
SATURATION OF THE LOW-LEVEL DRY AIR MASS. HOWEVER, THIS APPEARS
LIMITED AT BEST, AS MOST FORECAST SOUNDINGS INDICATE WHEN SATURATION
OCCURS, THE LAYER WARMS ABOVE FREEZING IN THE LOWEST 4 KFT OR SO. SO
ALL IN ALL, NO IMPACTS OF ANY KIND ARE EXPECTED.
SHORT TERM /SATURDAY AND SATURDAY NIGHT/
AS OF 135 PM FRIDAY...
ON SATURDAY MORNING A LOW PRESSURE SYSTEM DEVELOPING JUST OFF THE
FL/GA COAST WILL CONTINUE TO DEEPEN THROUGH THE DAY AS IT CONTINUES
NE JUST OF THE MID-ATLANTIC COAST. A STRONG COLD FRONT STRETCHING
ACROSS MUCH OF THE MISSISSIPPI VALLEY WILL BE APPROACHING THE MID-
ATLANTIC REGION BRINGING A CHANCE OF RAIN THROUGH MUCH OF THE DAY
SATURDAY. BY THE LATE AFTERNOON AND INTO THE EVENING HOURS COVERAGE
ACROSS THE REGION WILL BE COME MORE SCATTERED AND ISOLATED WITH DRY
CONDITIONS EXPECTED FOR MUCH OF THE LATE EVENING AND EARLY OVERNIGHT
HOURS. RAIN IS EXPECTED TO RETURN SHORTLY AFTER MIDNIGHT AS A
FRONTAL BOUNDARY SHIFTS NORTHWARD. EXPECT PERIOD OF RAIN TO CONTINUE
THROUGH SUNDAY MORNING. TOTAL RAINFALL ACCUMULATIONS (FROM SATURDAY
MORNING TO SUNDAY MORNING) ARE EXPECTED TO RANGE FROM A FEW
HUNDREDTHS IN THE NORTHERN PIEDMONT TO NEAR A 0.25” IN THE SOUTHERN
PORTIONS OF NC. WHILE MOST OF THE RAIN IS EXPECTED TO BE LIGHT,
THERE COULD BE A FEW WAVES OF MODERATE SHOWERS MOVING ACROSS SOME
PORTIONS OF CENTRAL NC. ONE HAZARD TO ALSO MENTION IS WITH A BRIEF
PERIOD OF CLEARING OVERNIGHT COULD RESULT IN SOME LOW VISIBILITIES
SATURDAY NIGHT INTO SUNDAY MORNING. SOME AREAS, ESPECIALLY ACROSS
THE PIEDMONT COULD SEE PATCHY DENSE FOG OVERNIGHT AND EARLY MORNING.
TEMPERATURES WILL BE ABOVE NORMAL SATURDAY WITH TEMPS IN THE EARLY
MORNING HOURS IN THE LOW TO MID 30S THEN WARMING THROUGH THE DAY
REACHING THE LOW TO MID 50S. SATURDAY NIGHT WILL BE THE LAST “ABOVE
NORMAL” NIGHT WITH LOWS RANGING FROM UPPER 30S NORTH, TO LOW 40S
SOUTH.
LONG TERM /SUNDAY THROUGH FRIDAY/
AS OF 257 PM FRIDAY...
SUNDAY: A WEAK WAVE OF LOW PRESSURE WILL MOVE ACROSS CENTRAL NC
SUNDAY JUST AHEAD OF A STRONG ARCTIC FRONT. STRONG UPPER-DIVERGENCE
WILL SLIDE OVER OUR AREA AND COMBINE WITH LINGERING ANOMALOUS
MOISTURE TO PROMOTE CONTINUED PRECIPITATION CHANCES INTO FRIDAY
AFTERNOON. FORECAST SOUNDINGS CONTINUE TO SUGGEST PRECIPITATION
SHOULD PRIMARILY FALL AS LIQUID, WITH A LOW QPF OF A FEW HUNDREDS TO
A TENTH EXPECTED. THERE IS A LOW-END CHANCE THAT A BRIEF CHANGE
OVER TO A RAIN/SNOW MIX WILL BE POSSIBLE FOR THOSE NORTH OF I-85,
BUT THIS WILL BE A CLASSIC CASE OF THE COLD AIR CHASING THE
MOISTURE. THE PROFILE DRIES OUT QUITE QUICKLY, SO EVEN IF SNOW
DEVELOPS, IT'LL BE SHORT LIVED AND BE INCONSEQUENTIAL.
PRE-FRONTAL TEMPERATURES WILL RISE INTO THE UPPER 40S TO UPPER 50S
(NW TO SE) SUNDAY AFTERNOON. 925 TO 850 MB CAA WILL REALLY RAMP UP
SUNDAY EVENING AS SFC WINDS GUST UP TOWARDS 25 TO 35 MPH. EXPECT
TEMPS TO BOTTOM OUT IN THE UPPER TEENS TO LOWER 20S SUNDAY
NIGHT/EARLY MONDAY MORNING.
MONDAY THROUGH WEDNESDAY: THIS PERIOD WILL FEATURE SOME OF THE
COLDEST AIR WE'VE EXPERIENCED OVER THE PAST FEW YEARS. HIGHS ON BOTH
MONDAY AND TUESDAY WILL STRUGGLE TO REACH THE UPPER 20S (N) AND
LOWER TO MID 30S ALONG THE SC BORDER. OVERNIGHT LOWS WILL BE
PARTICULARLY COLD, WITH TEMPS DIPPING INTO THE LOWER TEENS BOTH
MONDAY AND TUESDAY (SOME SPOTS MAY DIP INTO THE UPPER SINGLE
DIGITS). RESIDUAL LIGHT WINDS WILL PROMOTE POCKETS OF SINGLE DIGIT
WIND CHILLS BOTH MORNINGS AS WELL.
PRECIPITATION WISE, THERE STILL APPEARS TO BE POTENTIAL FOR A WINTER
SYSTEM PRIMARILY TUESDAY NIGHT INTO WEDNESDAY. HOWEVER, THERE IS
STILL CONSIDERABLE UNCERTAINTY WRT TO PATTERN EVOLUTION AND
CONSEQUENTLY SNOW CHANCES FOR OUR AREA. THE ECMWF HAS BEEN THE MOST
CONSISTENT MODEL THUS FAR, SIMULATING A MOSTLY OPEN WAVE THAT SCOOTS
OFF THE SOUTHEAST COAST DURING THIS TIME. THIS SCENARIO WOULD
PROMOTE VERY LITTLE SNOW ACCUMULATION FOR OUR AREA, CONFINING ANY
HIGHER AMOUNTS ALONG THE COAST. THE DETERMINISTIC CMC AND THE 06
AND 12Z GFS RUNS ARE MUCH MORE BULLISH DEVELOPING A LEGIT COASTAL
LOW WHICH WOULD PROMOTE BETTER SNOW CHANCES FOR MUCH OF CENTRAL NC.
HOWEVER, THE GFS IN PARTICULAR HAS BEEN QUITE INCONSISTENT WITH THIS
SYSTEM, AND IN FACT LOOKED MORE SIMILAR TO THE ECWMF SOLUTION JUST
12 HOURS EARLIER AT THE 00Z JANUARY 17 RUN (I.E. LITTLE TO NO SNOW,
MOSTLY CONFINED TO THE COAST). GIVEN THE INCONSISTENCIES AND
DISAGREEMENT THIS FAR OUT, KEPT POPS SIMILAR TO THE ENSEMBLE MEAN
PROBABILITIES FOR MEASURABLE QPF (ENS, GEFS, AND GEPS ALL HAVE
GENERALLY 40 TO 60% TUESDAY NIGHT).
BEYOND WEDNESDAY, MODELS ARE HINTING AT ANOTHER POTENTIAL SYSTEM
FRIDAY, BUT IT'S TOO FAR OUT TO GET INTO ANY DETAILS AT THIS POINT.
AVIATION /06Z SATURDAY THROUGH WEDNESDAY/
AS OF 1250 AM SATURDAY...
CLOUDS WILL THICKEN FROM WEST TO EAST OVERNIGHT AND WILL LOWER TO 5-
10 KFT BY 12Z AS PRECIP SPREADS IN FROM THE WEST. SPOTTY LIGHT RAIN
WILL OVERSPREAD THE AREA BETWEEN 12 TO 18Z, BEFORE EXITING.
CONDITIONS ARE EXPECTED TO REMAIN PREDOMINATELY VFR AS THE RAIN
MOVES THROUGH THE AREA. A LULL IN PRECIPITATION IS EXPECTED DURING
THE REMAINDER OF THE AFTERNOON AND EVENING, DURING WHICH TIME
CEILINGS ARE TO LOWER TO IFR AND EVENTUALLY LIFR OVERNIGHT.
ADDITIONALLY, AREAS OF FOG, POTENTIALLY DENSE, WILL BE POSSIBLE AS
AN AREA OF LOW PRESSURE AND OCCLUDED FRONT LIFTS INTO THE AREA.
LIGHT S-SWLY WINDS OF 5-10 KTS ARE EXPECTED TODAY, WITH SOME BRIEF
GUSTINESS OF 15-20 KTS POSSIBLE, THOUGH CONFIDENCE IS LOW IF THESE
GUSTS WILL MATERIALIZE.
OUTLOOK: WIDESPREAD IFR TO LIFR RESTRICTIONS WILL LINGER THROUGH
MIDDAY MIDDAY SUNDAY AS A COLD FRONT AND ASSOCIATED SCATTERED RAIN
SHOWERS MOVE THROUGH THE AREA. CONDITIONS WILL IMPROVE AND
EVENTUALLY RETURN TO VFR FROM SW TO NE DURING THE AFTERNOON AND
EVENING. ADDITIONALLY, PRECIP COULD END AS A BRIEF CHANGEOVER TO
SNOW ACROSS THE NORTHERN TAF SITES LATE SUNDAY AFTERNOON AND
EVENING.
VFR CONDITIONS ARE EXPECTED MONDAY AND TUESDAY. FORECAST
UNCERTAINTY IS HIGH, HOWEVER A POTENTIAL WINTER STORM SYSTEM COULD
BRING SUB-VFR RESTRICTIONS IN SNOW TUESDAY NIGHT/EARLY WEDNESDAY.
CLIMATE
RECORD LOW MAXIMUM TEMPERATURES:
JANUARY 20:
KGSO: 29/1983
KRDU: 28/1970
JANUARY 21:
KGSO: 21/1985
KFAY: 31/1983
JANUARY 22:
KGSO: 29/2014
KRDU: 27/1970
RAH WATCHES/WARNINGS/ADVISORIES
NONE.
SYNOPSIS...BADGETT/CBL
NEAR TERM...KREN
SHORT TERM...CA
LONG TERM...LUCHETTI
AVIATION...CBL
CLIMATE...RAH
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