709
FXUS62 KGSP 140606
AFDGSP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
106 AM EST THU NOV 14 2024
SYNOPSIS
CLOUDS AND PRECIPITATION WILL MAKE FOR A VERY DAMP AND CHILLY
DAY. DRY WEATHER AND A WARMING TREND ARE EXPECTED FRIDAY THROUGH
MONDAY.
NEAR TERM /THROUGH TODAY/
AS OF 100 AM EST THURSDAY: NO MAJOR CHANGES WERE NEEDED AS THE
FORECAST REMAINS ON TRACK THIS MORNING. STARTING TO SEE LIGHT RAIN
OVERSPREAD THE WESTERN HALF OF THE FORECAST AREA WITH BKN TO OVC
CLOUD COVER IN PLACE THIS MORNING.
A SURFACE RIDGE REMAINS IN PLACE IN COLD AIR DAMMING CONFIGURATION
ACROSS THE AREA AS A COLD FRONT APPROACHES FROM THE WEST. THE
LEADING EDGE OF WIDESPREAD SHOWERS ASSOCIATED WITH DEEPER MOISTURE
AND FORCING IS BEGINNING TO MOVE INTO THE WESTERN PART OF THE CWA
THIS MORNING, AND WILL STEADILY OVERSPREAD THE REST OF THE CWA OVER
THE NEXT FEW HOURS. STRONG SYNOPTIC SCALE FORCING IS EXPECTED AS A
NEGATIVELY TILT SHORT WAVE TROUGH ACCOMPANIES THE FRONT AND
DIVERGENCE INCREASES IN THE EXIT REGION OF AN UPPER JET MAX.
ISENTROPIC LIFT STRENGTHENS AS A SOUTHEASTERLY LOW LEVEL JET
DEVELOPS...INCREASING UPSLOPE FLOW. CATEGORICAL POPS SPREAD ACROSS
THE AREA THROUGH EARLY THIS MORNING, WITH CHANCES DIMINISHING FROM
WEST TO EAST DURING THE AFTERNOON AS THE COLD FRONT MOVES IN FROM
THE WEST. THE LATEST SURFACE ANALYSIS DEPICTS WET BULB TEMPS AT OR
JUST BELOW FREEZING ACROSS THE HIGHEST ELEVATIONS OF WESTERN NC THIS
MORNING AHEAD OF THE PRECIP SHIELD. FORECAST SOUNDINGS CONTINUE TO
INDICATE STRONG ADVECTION OF WARM AND MOIST AIR OCCURRING ABOVE THE
STABLE SURFACE LAYER, WITH A VERY DEEP AND STRONG WARM NOSE
DEVELOPING NOT LONG AFTER PRECIP DEVELOPMENT. THUS, WHILE THERE
COULD BE A BRIEF PERIOD OF SLEET ABOVE 4500' OR SO, WARM ADVECTION
WILL QUICKLY ERADICATE ANY LINGERING COLD LAYERS.
MOST LOCATIONS ALONG AND NORTH OF THE I-85 CORRIDOR, EXCEPT FOR SOME
NORTHWESTERLY FACING RAIN SHADOW LOCATIONS, ARE EXPECTED TO RECEIVE
A SOLID SOAKING OF 1 TO 1.25 INCHES OF STORM TOTAL RAINFALL. SOUTH
OF I-85 WILL STILL SEE BETWEEN 0.5 AND 1 INCH, WITH SLIGHTLY LOWER
AMOUNTS FOR THE RAIN SHADOW AREAS. FAVORED UPSLOPE AREAS WILL SEE
CLOSER TO 2 INCHES, BUT ANTECEDENT CONDITIONS SHOULD PRECLUDE ANY
FLOODING. GIVEN THE STRENGTH OF THE FORCING AND SOME SCANT/ELEVATED
INSTABILITY, CAN'T RULE OUT A LIGHTNING STRIKE HERE OR THERE,
ESPECIALLY DURING THE DAYLIGHT HOURS.
SOUTHEASTERLY WIND SPEEDS AND GUSTS WILL INCREASE ACROSS THE HIGHER
ELEVATIONS THIS MORNING WITH THE STRENGTHENING LOW LEVEL JET THEN
FLIP TO THE NORTHWEST DURING THE AFTERNOON BEHIND THE FRONT.
OCCASIONAL NORTHEASTERLY GUSTS WILL BE SEEN OUTSIDE OF THE MOUNTAINS
AS WELL. ALL GUSTS SHOULD REMAIN BELOW ADVISORY CRITERION.
LOWS THIS MORNING WILL BE AS MUCH AS 5 DEGREES ABOVE NORMAL WITH A
NON-DIURNAL TREND LIKELY ACROSS THE MOUNTAINS, TEMPS RISING THROUGH
THE EARLY MORNING HOURS AFTER WET BULBING DOWN DURING PRECIP ONSET.
TEMPERATURES TODAY WILL SHOW A TYPICAL CAD CONFIGURATION...HIGHS
AROUND 15 DEGREES BELOW NORMAL OUTSIDE OF THE MOUNTAINS, AND 10
DEGREES BELOW NORMAL FOR MUCH OF THE MOUNTAINS EXCEPT FOR THE LITTLE
TN BASIN AND OTHER LOWER VALLEY LOCATIONS NEAR THE TN BORDER WHERE 5
DEGREES BELOW NORMAL WILL BE COMMON.
SHORT TERM /TONIGHT THROUGH SATURDAY/
AS OF 230 PM EST WEDNESDAY: PRECIP WILL BE MOVING OUT AS WE MOVE
INTO THE SHORT TERM, WITH SOME FRONTAL PRECIP STILL IN THE NW
PIEDMONT AND MOISTURE ASSOCIATED WITH THE UPPER TROUGH ITSELF PUSHING
INTO THE MOUNTAINS. POPS WILL LIFT RAPIDLY FROM PIEDMONT BUT NW
UPSLOPE FLOW WILL ALLOW PRECIP TO LINGER TOWARD DAYBREAK IN THE
NORTHERN MOUNTAINS, THOUGH CAA NOT QUITE STRONG ENOUGH TO BRING ANY
MIXED PRECIP CONCERNS AT THIS TIME. NEW GUIDANCE HAS COME DOWN WITH
POST-FRONTAL WIND GUSTS EARLY FRIDAY IN THE HIGHEST ELEVATIONS BUT
STILL EXPECT GUSTY WINDS 35MPH+ WITH MOUNTAIN WAVE ACTIVITY AS THE
UPPER TROUGH PUSHES THROUGH.
GRADIENT WEAKENS DURING THE DAY ON FRIDAY AND AS USUAL POST-CAD WITH
SUNSHINE AND DOWNSLOPE FLOW EXPECT A SIGNIFICANT WARM-UP WITH HIGHS
IN THE MID 60S IN THE PIEDMONT. WITH UPPER RIDGING BUILDING IN JUST
TO THE WEST ON SATURDAY AND SOUTHERLY WAA INCREASING AT THE SURFACE,
EXPECT ANOTHER UPTICK FOR HIGHS AS WE START THE WEEKEND.
LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/
AS OF 300 PM EST WEDNESDAY: UPPER RIDGE WITH SURFACE HIGH WILL
DOMINATE THE AREA AS WE START THE EXTENDED, WITH THE WAVETRAIN
MOVING EAST QUICKLY INTO EARLY NEXT WEEK. REALLY PLEASANT CONDITIONS
EXPECTED WITH GRADUAL WARMING EACH DAY THROUGH TUESDAY AHEAD OF THE
NEXT SYSTEM, WHICH WILL BE GEARING UP OVER THE PLAINS EARLY IN THE
WEEK. THERE'S QUITE A BIT OF UNCERTAINTY THIS FAR OUT AS TO EXACTLY
HOW THE PATTERN WILL EVOLVE AS THE SYSTEM APPROACHES, BUT RIGHT NOW
THE PLAINS TROUGH IS PROGGED TO LIFT TOWARD THE UPPER MS VALLEY BY
TUESDAY MORNING, DRAGGING A COLD FRONT TOWARD THE TN VALLEY AND
BRINGING POPS INTO EXTREME WESTERN ZONES TUESDAY MORNING. NO
CONCERNS FOR WINTRY PRECIP AT THIS TIME, ALL LIQUID. GLOBAL MODELS
CURRENTLY HAVE THE FRONT SORT OF FALLING APART OVER THE APPALACHIANS
AS THE INITIAL UPPER LOW GETS ABSORBED INTO THE LONGWAVE PATTERN, A
DEEPER TROUGH DIGGING OUT OF CANADA THAT LOOKS TO IMPACT THE CENTER
OF THE COUNTRY TOWARDS THE EXTENDED. FOR NOW HAVE KEPT POPS
GENERALLY AT MID-RANGE CHANCE IN THE MOUNTAINS AND SLIGHT CHANCE
EAST AT THE END OF THE PERIOD.
AVIATION /06Z THURSDAY THROUGH MONDAY/
AT KCLT AND ELSEWHERE: A COLD FRONT APPROACHING OUT OF THE WEST
IS LEADING TO BKN TO OVC VFR CLOUD COVER ACROSS THE TERMINALS AND
RAIN ACROSS THE WESTERN HALF OF THE FORECAST AREA AS OF 06Z. LLWS
CANNOT BE ENTIRELY RULED OUT, ESPECIALLY AT KAVL, THROUGH THE
MORNING HOURS BUT THE LLWS POTENTIAL LOOKS MARGINAL AT BEST SO DID
NOT MENTION IN THE TAFS AT THIS TIME. RAIN WILL CONTINUE TO EXPAND
NORTHEASTWARD AND CIGS WILL GRADUALLY LOWER THROUGH LATE THIS
MORNING INTO EARLY THIS AFTERNOON. CIGS SHOULD MAINLY DROP TO IFR
LEVELS WITH THE POTENTIAL FOR HIGH-END LIFR CIGS IN THE HEAVIEST
SHOWERS. STARTED WITH TEMPOS FOR RA TOWARDS THE BEGINNING OF THE TAF
PERIOD, WITH PREVAILING RA AFTER THE TEMPOS END. RA SHOULD STICK
AROUND THROUGH THE LATE AFTERNOON/EARLY EVENING HOURS BEFORE
GRADUALLY TAPERING OFF FROM WEST TO EAST. VSBYS WILL DECREASE AS
WELL WITH THE RAIN SHIELD, RANGING MOSTLY FROM MVFR TO IFR. PATCHY
FOG LOOKS TO STICK AROUND/REDEVELOP TONIGHT INTO DAYBREAK FRIDAY
EAST OF THE MOUNTAINS SO HAVE THIS ACCOUNTED FOR TOWARDS THE END OF
THE TAF PERIOD. CLOUD COVER WILL GRADUALLY THIN OUT LATE THIS
AFTERNOON INTO THIS EVENING BECOMING SCT TO BKN. CIGS WILL GRADUALLY
LIFT TO MVFR LEVELS LATE THIS AFTERNOON INTO THIS EVENING. WINDS
WILL REMAIN SE AT KAVL AND NE EAST OF THE MOUNTAINS THROUGH THE
MORNING HOURS. WINDS WILL THEN GRADUALLY TURN N/NW ACROSS THE
TERMINALS BEHIND THE COLD FRONT THIS AFTERNOON INTO THIS EVENING.
OUTLOOK: HIGH PRESSURE BRINGS DRY AND VFR CONDITIONS BACK FRIDAY
INTO EARLY NEXT WEEK.
GSP WATCHES/WARNINGS/ADVISORIES
GA...NONE.
NC...NONE.
SC...NONE.
SYNOPSIS...TDP
NEAR TERM...AR/JDL/RWH
SHORT TERM...TDP
LONG TERM...TDP
AVIATION...AR
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