556
FXUS62 KGSP 191139
AFDGSP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
639 AM EST WED FEB 19 2025
SYNOPSIS
WINTRY WEATHER IS LIKELY FOR PARTS OF THE AREA TODAY AS A
FAST-MOVING LOW PRESSURE SYSTEM PASSES ACROSS THE SOUTHEAST. DRY
HIGH PRESSURE RETURNS THURSDAY BRINGING VERY COLD WEATHER TO END
THE WEEK. A DRY PATTERN WITH A WARMING TREND IS EXPECTED TO BEGIN
OVER THE WEEKEND, WITH ABOVE-NORMAL TEMPERATURES EXPECTED TO RETURN
EARLY NEXT WEEK.
NEAR TERM /THROUGH THURSDAY/
AS OF 635 AM WED: RADAR AND SURFACE REPORTS SHOWING SLIGHT SNOW
MOVING INTO THE MOUNTAINS AT THIS TIME. SOME OF THIS WILL SPREAD
ACROSS THE FOOTHILLS AND PIEDMONT AS WELL, BEFORE BECOMING MORE
WIDESPREAD THROUGH THE MORNING.
OTHERWISE, COMPLICATED WEATHER PATTERN SETTING UP FOR THIS PERIOD.
WEAK HIGH PRESSURE BUILDS INTO THE AREA FROM THE NORTH TODAY IN A
COLD AIR DAMMING PATTERN WHILE A LOW PRESSURE AREA MOVES EAST ALONG
THE GULF COAST. THE LOW REACHES THE ATLANTIC COAST BY THE END OF THE
DAY AND MOVES NORTHEAST NEAR THE COAST TONIGHT WHILE THE DAMMING
HIGH WEAKENS. SHORT WAVE ENERGY CROSSES THE AREA TODAY, THEN A
STRONGER SHORT WAVE ROTATING AROUND AN UPPER LOW CROSSES THE AREA
THURSDAY WITH A WEAK CLIPPER TYPE LOW MOVING ACROSS THE CENTRAL
APPALACHIANS INTO THE MID-ATLANTIC.
DEEP MOISTURE AND LOW LEVEL ISENTROPIC LIFT MOVE INTO THE AREA TODAY
WITH WEAK SYNOPTIC SCALE FORCING. PRECIP INITIALLY MOVES INTO THE
MOUNTAINS EARLY THIS MORNING THEN SPREADS ACROSS THE AREA THROUGH
THE MORNING. A DRY SLOT DEVELOPS AS THE LOW MOVES EAST AND LOW LEVEL
FLOW BECOMES MORE NORTHERLY. THE SYNOPTIC AND CAM GUIDANCE ARE IN
GENERAL AGREEMENT ON THIS. FORECAST SOUNDINGS LOOK LIKE A RAIN/SNOW
SOUNDING WITH LITTLE IN THE WAY OF A WARM NOSE. THIS LEADS TO ENOUGH
COLD AIR IN PLACE FOR PRECIP TO START AS SNOW FOR THE NC COUNTIES
WITH MAINLY RAIN FOR THE UPSTATE AND NE GA. THAT SAID, SNOW OR SLEET
MAY MIX IN ACROSS THE MOUNTAINS OF NE GA AND THE UPSTATE. THESE P-
TYPES GENERALLY HOLD STEADY AS THE PRECIP CROSSES THE AREA, BUT SOME
WARMING TAKES PLACE DURING THE AFTERNOON WITH MAINLY RAIN DEVELOPING
ACROSS THE VALLEYS WEST OF THE FRENCH BROAD. THE CHARLOTTE METRO ARE
WILL ALSO BE ON THE EDGE OF THE LOW LEVEL COLD AIR. THE OLD TROPE OF
I-85 BEING A DIVIDING LINE FOR RAIN/SNOW COULD WORK OUT ONCE AGAIN.
THE OTHER COMPLICATING FACTOR IS THE WEAK MOISTURE INFLOW FROM THE
GULF AND ATLANTIC. THIS LIMITS QPF AND RESULTING WINTRY PRECIP
ACCUMULATION POTENTIAL. FOR NOW, HAVE 1 TO 2 INCHES ACROSS THE NC
MOUNTAINS, AROUND AN INCH FOR THE I-40 CORRIDOR, AND A DUSTING TO
HALF AN INCH FOR THE SOUTHERN FOOTHILLS AND PIEDMONT AND RABUN
COUNTY GA TODAY. FREEZING RAIN LOOKS UNLIKELY NOW, SO NO ICE
ACCRETION NOTED. NO SIGNIFICANT ACCUMS SOUTH OF THESE AREAS.
A LULL IN THE PRECIP DEVELOPS THIS EVENING AS THE DRY SLOT MOVES IN
FROM THE SW AS THE LOW MOVES NORTH OF THE AREA. SOME ELEVATION
DEPENDENT RAIN/SNOW SHOWERS LINGER ACROSS THE MOUNTAINS. PRECIP
CHANCES THEN RAMP BACK UP ACROSS THE AREA LATE TONIGHT AND THURSDAY
MORNING AS THE AFORE MENTIONED SHORT WAVE CROSSES THE AREA. THIS
WILL KEEP SNOW SHOWERS ACROSS THE MOUNTAINS WITH A RETURN OF SNOW
SHOWERS TO THE NC FOOTHILLS AND PIEDMONT, ALONG WITH THE CENTRAL AND
EASTERN UPSTATE. THIS MAY LEAD TO A DUSTING TO HALF AN INCH FOR THE
NON-MOUNTAIN AREAS. THE SNOW SHOWERS END BY AFTERNOON OUTSIDE OF THE
MOUNTAINS WITH NW FLOW SNOW CONTINUING ACROSS THE NC MOUNTAINS.
STORM TOTAL ACROSS THE MOUNTAINS WILL BE HIGHLY VARIABLE ON
ELEVATIONS WITH MANY VALLEYS AWAY FROM THE TN BORDER SEEING AN INCH
OR LESS. ALONG THE TN BORDER, AMOUNTS WILL RANGE FROM 2 TO 4 INCHES
WITH LOCALLY HIGHER AMOUNTS IN THE USUAL HIGH ELEVATION LOCATIONS IN
THE SMOKIES, ROAN AND BEECH MTNS, ETC.
GIVEN THE TIMING AND ACCUMULATION COMPLICATIONS, WILL NOT MAKE ANY
CHANGES TO THE WINTER WEATHER ADVISORY AT THIS TIME. THE NEXT SHIFT
MAY BE ABLE TO CANCEL PARTS OF IT EARLY AS THE SITUATION UNFOLDS
WHERE ACCUMS END UP BEING LIMITED.
HIGH TEMPERATURES TODAY WILL BE TRICKY GIVEN THE COLD AIR MASS AND
PRECIP, BUT SHOULD HAVE A CAD PATTERN TO THE GRADIENT, WITH VALUES
15 TO 20 DEGREES BELOW NORMAL. LOWS TONIGHT WILL BE 10 TO 15 DEGREES
BELOW NORMAL, AND HIGHS THURSDAY 20 TO 25 DEGREES BELOW NORMAL AS A
VERY COLD AIR MASS MOVES IN. WITH BREEZY TO WINDY CONDITIONS,
ESPECIALLY ON THURSDAY, WIND CHILL VALUES WILL DROP BELOW ZERO
ACROSS THE HIGHER ELEVATIONS OF THE NC MOUNTAINS. A COLS WEATHER
ADVISORY MAY BE NEEDED. WIND GUSTS WILL INCREASE TO 45 MPH OR MORE
ACROSS THE HIGHER ELEVATIONS AS WELL. THEY SHOULD REMAIN BELOW HIGH
WIND WARNING LEVEL, BUT A WIND ADVISORY MAY BE NEEDED.
SHORT TERM /THURSDAY NIGHT THROUGH FRIDAY NIGHT/
AS OF 230 AM WEDNESDAY: THE CENTER OF AN ARCTIC HIGH PRESSURE SYSTEM
WILL PUSH INTO THE MIDWEST, WITH ENOUGH PRESSURE GRADIENT AND CAA
TO KEEP WINDS UP ACROSS THE MOUNTAINS. TEMPS WILL PLUMMET INTO THE
SINGLE DIGITS AND TEENS, COMBINED WITH THE WINDS TO PRODUCE WIND
CHILLS BELOW ZERO IN MUCH OF THE MOUNTAINS ABOVE 3500 FT. WILL
LIKELY NEED A COLD ADVISORY FOR THE NORTHERN MOUNTAINS ABOVE 3500
FT, AS WIND CHILLS DROP BELOW -5. ADVISORY CRITERIA LOOKS TO BE
ABOVE AROUND 5000 FT ACROSS THE REST OF THE MOUNTAINS. OTHERWISE,
COULD SEE A FEW LINGERING SNOW SHOWERS ALONG THE TN BORDER THURSDAY
EVENING, TAPERING OFF TO SOME FLURRIES AND ENDING COMPLETELY BY
DAYBREAK FRIDAY. THE CENTER OF HIGH PRESSURE WILL MIGRATE TO THE
CENTRAL APPALACHIANS BY 12Z SATURDAY. SKIES LOOK CLEAR FRIDAY, BUT
SOME INCREASE IN MAINLY HIGH CLOUDS POSSIBLE FRIDAY NIGHT, WITH
WINDS BECOMING LIGHT. LOWS WILL BE ABOUT 15-20 DEG BELOW NORMAL
THURSDAY NIGHT, THEN A GRADUAL WARMING TREND WILL COMMENCE. HIGHS
FRIDAY SHOULD BE A COUPLE CATEGORIES WARMER THAN THURSDAY, BUT
STILL 10-15 DEG BELOW NORMAL. LOWS FRIDAY NIGHT WILL ALSO BE NOT
AS COLD, ABOUT 8-14 DEG BELOW NORMAL.
LONG TERM /SATURDAY THROUGH TUESDAY/
AS OF 130 AM WEDNESDAY: THE MEDIUM RANGE LOOKS DRY WITH A GRADUAL
WARMING TREND OVER THE WEEKEND AND INTO NEXT WEEK. A SERIES
OF SHORTWAVES WILL RIDE THRU A GENERAL WEST-NORTHWESTERLY FLOW
ALOFT, BUT WITH LITTLE MOISTURE TO WORK WITH. THE WAVES MAY BRING
BRIEF PERIODS OF NW FLOW RAIN OR SNOW SHOWERS, BUT WITH MINIMAL
IMPACTS. IN FACT, POPS ARE STILL TOO LOW TO BE MENTIONABLE. TEMPS
SHOULD BE NEAR NORMAL BY SUNDAY AND UP TO 10 DEGREES OR MORE ABOVE
NORMAL BY TUESDAY.
AVIATION /12Z WEDNESDAY THROUGH SUNDAY/
AT KCLT AND ELSEWHERE: MIXED PRECIP MOVING INTO THE AREA ALONG
WITH LOW VFR CIGS. CONDITIONS DETERIORATE THROUGH THE DAY WITH
BETTER PRECIP CHANCES AND MVFR CONDITIONS. CIGS FALL TO IFR BY
AFTERNOON WITH GENERALLY MVFR VSBY. IFR VSBY POSSIBLE WHERE PRECIP
RATES ARE HIGH ENOUGH. EXPECT MAINLY RAIN AT THE SC SITES, BUT SNOW
MIXING IN POSSIBLE AT KGSP/KGMU. SNOW EXPECTED AT THE NC SITES WITH
SOME SLEET POSSIBLE, BUT KCLT COULD BE MORE OF A RAIN/SNOW MIX.
LOOKS TO BE A LULL IN PRECIP BY LATE AFTERNOON, BUT MVFR VSBY AND
LIFR CIGS DEVELOP. MVFR TO VFR VSBY AND LIFR CIGS OVERNIGHT. NE WIND
EXPECTED THROUGH THE PERIOD. KAVL THE EXCEPTION WITH LIGHT SE WIND
THIS MORNING BECOMING N IN THE AFTERNOON BECOMING GUSTY OVERNIGHT.
OUTLOOK: WET SURFACES MAY FREEZE AS TEMPERATURES FALL BELOW FREEZING
DEICING COULD BE NECESSARY THU MORNING. DRY HIGH PRESSURE RETURNS
LATE THURSDAY AND LINGERS INTO THE WEEKEND.
GSP WATCHES/WARNINGS/ADVISORIES
GA...WINTER WEATHER ADVISORY UNTIL NOON EST THURSDAY FOR GAZ010.
NC...WINTER WEATHER ADVISORY UNTIL NOON EST THURSDAY FOR NCZ033-
035>037-048>053-056>059-062>065-068>072-082-501>510.
SC...NONE.
SYNOPSIS...ARK/JDL
NEAR TERM...RWH
SHORT TERM...ARK
LONG TERM...ARK
AVIATION...RWH
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