502
FXUS62 KGSP 191931
AFDGSP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
231 PM EST WED FEB 19 2025
SYNOPSIS
ANOTHER ROUND OF SNOW SHOWERS MAY IMPACT OUR AREA THURSDAY MORNING.
DRY HIGH PRESSURE WILL THEN RETURN LATER 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 100 PM EST WEDNESDAY: GETTING A FEW FLURRIES ACROSS THE
NORTHERN UPSTATE, PORTIONS OF NORTHEAST GA, AND NC PIEDMONT AS THIS
FIRST WAVE OF PRECIP SLIPS ACROSS THE AREA. A LULL IN THE PRECIP IS
STILL EXPECTED LATER THIS AFTERNOON/EVENING. OTHERWISE, THE FORECAST
REMAINS MOSTLY ON TRACK WITH UPDATES BASED ON CURRENT OBSERVATIONS
AND LATEST MODEL TRENDS.
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 SATURDAY/
AS OF 200 PM WEDNESDAY: COLD NW FLOW WILL CONTINUE INTO THE SOUTHERN
APPALACHIANS AND VICINITY THU NIGHT INTO EARLY FRI. ALTHOUGH
MOISTURE ON THE WESTERN SLOPES WILL BE SHALLOW DURING THIS TIME
FRAME, TEMPS IN THE MOIST LAYER WILL BE MORE THAN COLD ENOUGH TO
SUPPORT ICE CRYSTAL NUCLEATION...SO LIGHT SNOW SHOWERS AND FLURRIES
WILL REMAIN POSSIBLE ALONG THE TN/NC BORDER BEFORE THE MOISTURE
DEPLETES BY AROUND DAYBREAK FRIDAY. OTHERWISE, SPRAWLING SURFACE
HIGH PRESSURE WILL SETTLE OVER THE REGION THROUGH THE END OF THE
PERIOD, RESULTING IN A RELAXING PRESSURE GRADIENT, DRY AIR, AND
BELOW NORMAL TEMPERATURES. SOME DEGREE OF ENHANCED WILDFIRE DANGER
APPEARS LIKELY FOR AT LEAST FRIDAY, AS MINIMUM RH IS FORECAST AT
20-25% FOR MUCH OF THE AREA OUTSIDE THE MOUNTAINS. TEMPS WILL
GRADUALLY MODIFY THROUGH THE PERIOD...WITH THU NIGHT LOWS EXPECTED
TO BE AROUND 20 DEGREES BELOW NORMAL...AND FRI NIGHT MINS ABOUT 15
DEGREES BELOW. MAX TEMPS WILL BE 5-10 DEGREES BELOW CLIMO.
LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/
AS OF 220 PM WEDNESDAY: A GENERALLY DRY/FAST WNW FLOW ALOFT IS
EXPECTED TO IMPACT THE SOUTHEAST AND MID-ATLANTIC THROUGH THE MEDIUM
RANGE. THE PROGRESSIVE NATURE OF THE PATTERN WILL BRING MULTIPLE,
DAMPENING SHORT WAVE TROUGHS THROUGH OR NEAR THE FORECAST AREA
THROUGH THE PERIOD. ONE OF THESE MAY INITIATE A COASTAL SURFACE
WAVE CLOSE ENOUGH TO THE CWA TO BRING RAIN CHANCES TO THE PIEDMONT
SUN NIGHT/MON...BUT THE CONSENSUS OF GLOBAL MODEL GUIDANCE INDICATES
A POP-FREE FORECAST SHOULD BE MAINTAINED FOR THE TIME BEING. OTHER
DISTURBANCES COULD BRING MOUNTAIN/NW FLOW SHOWERS, BUT AGAIN, THE
EXPECTATION OF A GENERALLY DRY AIR MASS WILL PRECLUDE A POP MENTION
FOR THIS. OTHERWISE, MAX TEMPS WILL ARM THROUGH THE PERIOD...
ALTHOUGH THE RELATIVELY DRY AIR IS GENERALLY EXPECTED TO SUPPORT
LARGE DIURNAL TEMP RANGES SUCH THAT FORECAST HIGHS ARE 5-10 DEGREES
ABOVE NORMAL MON-WED, WHILE MIN TEMPS ARE EXPECTED TO BE WITHIN THE
BALLPARK OF NORMAL.
AVIATION /20Z WEDNESDAY THROUGH MONDAY/
AT KCLT AND ELSEWHERE: FIRST AREA OF PRECIP IS CURRENTLY PUSHING
THROUGH THE TERMINALS WITH A CHANCE FOR -SN AT THE NC SITES AND
-RASN AT THE SC SITES THROUGH 20Z-22Z BEFORE SHIFTING TO THE
EAST. CIGS WILL GRADUALLY LOWER THROUGH THE AFTERNOON AS MOST TAF
SITES ARE FORECASTED TO BE MVFR/IFR BY 00Z THURSDAY. NORTHEASTERLY
WINDS WILL CONTINUE THROUGH THIS EVENING AND INTO THE OVERNIGHT
HOURS, WHILE CIGS LIKELY GO PREVAILING IFR OVERNIGHT TONIGHT
AT ALL TERMINALS. KAVL WILL MAINTAIN A SOUTHEASTERLY COMPONENT
THROUGH SUNSET BEFORE MAKING A SWITCH OUT OF THE NORTHWEST. A
SECOND WAVE OF SNOW IS SHOWING UP VIA MODEL GUIDANCE JUST BEFORE
DAYBREAK THURSDAY AND MOVES FROM WEST TO EAST THROUGH THE REST OF
THE MORNING HOURS. INCLUDED A PROB30 FOR ALL TAF SITES AS THERE
IS STILL SOME UNCERTAINTY ON HOW WIDESPREAD COVERAGE WILL BE, BUT
A QUICK BURST OF LIGHT TO MODERATE SNOW HAS ENTERED THE FORECAST,
WITH ASSOCIATED RESTRICTIONS. BEHIND THE AREA OF SNOW, CLOUDS ARE
EXPECTED TO QUICKLY SCATTER OUT BY LATE MORNING TO EARLY AFTERNOON
WITH ALL SITES TOGGLING TO A NORTHWESTERLY DIRECTION WITH LOW-END
GUSTS FILTERING IN AS WELL THROUGH THE END OF THE FORECAST PERIOD.
OUTLOOK: WET SURFACES MAY FREEZE AS TEMPERATURES FALL BELOW
FREEZING DEICING COULD BE NECESSARY THURSDAY 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.
COLD WEATHER ADVISORY FROM 7 AM THURSDAY TO 10 AM EST FRIDAY
FOR NCZ033-048>052-058.
SC...NONE.
SYNOPSIS...JDL
NEAR TERM...CAC
SHORT TERM...JDL
LONG TERM...JDL
AVIATION...CAC
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