201
FXUS62 KGSP 171919
AFDGSP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
219 PM EST TUE DEC 17 2024
SYNOPSIS
TEMPERATURES WILL BE SEVERAL DEGREES ABOVE NORMAL THROUGH WEDNESDAY,
WITH A STRONG COLD FRONT APPROACHING FROM THE WEST AND INCREASING
RAIN CHANCES AREA-WIDE WEDNESDAY AFTERNOON AND EVENING. COOLER
CONDITIONS ARE EXPECTED BEHIND THE FRONT THROUGH THE WEEKEND WITH
TEMPERATURES SEVERAL DEGREES BELOW NORMAL SUNDAY AND MONDAY.
NEAR TERM /THROUGH WEDNESDAY/
AS OF 200 PM EST TUESDAY...
KEY MESSAGES:
1) MOSTLY DRY CONDITIONS EXPECTED THROUGH EARLY WEDNESDAY AFTERNOON
2) DENSE FOG RETURNS EAST OF THE MOUNTAINS TONIGHT INTO WEDNESDAY
MORNING
3) A COLD FRONT INCREASES RAIN CHANCES, MAINLY FOR THE MOUNTAINS,
LATE WEDNESDAY AFTERNOON INTO WEDNESDAY EVENING
CLOUD COVER CONTINUES TO GRADUALLY INCREASE FROM WEST TO EAST THIS
AFTERNOON AND SOME ISOLATED SPOTTER SHOWERS ARE FLOATING AROUND SO
WENT AHEAD AND MAINTAINED A SLIGHT CHANCE POP MENTION THROUGH THE
EARLY EVENING HOURS NORTH OF I-85. ALREADY SEEING TEMPS RANGE FROM
THE UPPER 50S TO MID 60S EAST OF THE MOUNTAINS AND IN THE MOUNTAIN
VALLEYS. SEEING SLIGHTLY COOLER TEMPS IN THE MID 40S TO LOWER 50S
ACROSS THE HIGHER ELEVATIONS. TEMPS SHOULD ONLY WARM A FEW MORE
DEGREES DURING PEAK HEATING HOURS, ENDING UP ~12-15 DEGREES ABOVE
NORMAL. MOSTLY DRY CONDITIONS WILL CONTINUE OVERNIGHT BUT DID
MAINTAIN A SLIGHT CHANCE POP ACROSS THE NC MOUNTAINS AND THE
NORTHERN NC PIEDMONT AS A FEW ISOLATED POCKETS OF RAIN MAY DEVELOP
AS A WARM FRONT LIFTS NORTH OVER THE REGION. LIGHT TO CALM WINDS
ALONG WITH LINGERING LOW-LEVEL MOISTURE WILL LEAD TO ANOTHER ROUND
OF DENSE FOG, MAINLY EAST OF THE MOUNTAINS, OVERNIGHT INTO EARLY
WEDNESDAY MORNING DESPITE MOSTLY CLOUDY SKIES. THUS, ANOTHER DENSE
FOG ADVISORY MAY NEED TO BE ISSUED FOR TOMORROW MORNING. LOWS
TONIGHT WILL BE ~20 DEGREES ABOVE NORMAL THANKS TO BOTH THE WARM
FRONT AND MOSTLY CLOUDY SKIES.
FOG SHOULD LIFT BY MID-MORNING AND DRY CONDITIONS WILL LINGER
THROUGH EARLY WEDNESDAY AFTERNOON. A COLD FRONT WILL TRACK ACROSS
THE FORECAST AREA LATE WEDNESDAY AFTERNOON/EVENING INCREASING RAIN
CHANCES, MAINLY FOR THE MOUNTAINS. CAMS DEPICT THE MOISTURE
ASSOCIATED WITH THE FRONT GRADUALLY FALLING APART AS IT PUSHES EAST
OF THE MOUNTAINS. THUS, THE HIGHEST POPS (~60%-80%) ARE IN PLACE
ACROSS THE WESTERN NORTH CAROLINA MOUNTAINS WITH POPS CAPPED TO ~35%
EAST OF THE MOUNTAINS WEDNESDAY AFTERNOON/EVENING. THE CAMS ARE NOT
IN AGREEMENT REGARDING THE ONSET OF RAIN TOMORROW. THE 12Z HRRR
SHOWS THE RAIN PUSHING ACROSS THE NC/TN BORDER ~20Z WEDNESDAY WHILE
THE NAMNEST DOES NOT SHOW RAIN PUSHING INTO THE MOUNTAINS UNTIL
AROUND OR JUST AFTER 00Z THURSDAY. ALTHOUGH CAMS AND FORECAST
SOUNDINGS DEPICT SOME ELEVATED INSTABILITY DURING PEAK HEATING ON
WEDNESDAY, OPTED TO REMOVE ANY MENTION OF THUNDER. DID THIS FOR TWO
REASONS: 1) THUNDER CHANCES WILL BE HIGHLY DEPENDENT ON WHETHER
CONVECTION AHEAD OF THE FRONT PUSHES THROUGH DURING PEAK HEATING AND
2) CONVECTION IS EXPECTED TO WEAKEN AS IT PUSHES EAST ACROSS THE
FORECAST AREA. THINKING IS THAT THERE WILL NOT EVEN BE MUCH RAIN TO
SPEAK OF EAST OF THE MOUNTAINS, LET ALONG THUNDER. HIGHS ON
WEDNESDAY WILL BE A FEW DEGREES WARMER THAN TODAY, ENDING UP ~15-17
DEGREES ABOVE NORMAL. SOME LOCATIONS MAY SEE A BRIEF BREAK IN CLOUD
COVER AHEAD OF THE FRONT ON WEDNESDAY, BUT MOSTLY CLOUDY SKIES
RETURN WITH THE FRONT WEDNESDAY AFTERNOON/EVENING.
SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY NIGHT/
AS OF 150 PM EST TUESDAY: THE SHORT WAVE AND FRONTAL SYSTEM FROM THE
NEAR TERM MOVE OUT OF THE AREA WEDNESDAY NIGHT. SHOWERS WILL QUICKLY
END DURING THE EVENING AS DRY HIGH PRESSURE BUILDS IN OVERNIGHT.
WINDY TO BREEZY CONDITIONS EXPECTED OVERNIGHT INTO THURSDAY BEFORE
THE PRESSURE GRADIENT RELAXES. ANOTHER SHORT WAVE MOVES MOVES INTO
THE AREA FRIDAY WITH A WEAKENING CLIPPER TYPE SURFACE LOW. THERE
LOOKS TO BE ENOUGH MOISTURE FOR NW FLOW SNOW TO DEVELOP ACROSS THE
USUAL LOCATIONS ALONG THE TN BORDER FRIDAY AFTERNOON AND EVENING.
RIGHT NOW, THERE DOESN'T LOOK TO BE AN EXTENDED PERIOD OF MOISTURE
FLUX OR FORCING, SO SNOW AMOUNTS SHOULD BE RELATIVELY LIGHT AND
LIMITED TO THE HIGHER ELEVATIONS. EXPECT WINDY TO BREEZY CONDITIONS
TO REDEVELOP ON FRIDAY AND CONTINUE INTO FRIDAY NIGHT. LOWS
WEDNESDAY NIGHT WILL BE 5 TO 10 DEGREES ABOVE NORMAL, DROPPING TO
NEAR NORMAL THURSDAY NIGHT AND A FEW DEGREES BELOW NORMAL FRIDAY
NIGHT. HIGHS THURSDAY WILL BE A FEW DEGREES ABOVE NORMAL THEN
DROPPING A LITTLE BELOW NORMAL FOR THE MOUNTAINS ON FRIDAY BUT
REMAINING NEARLY STEADY ELSEWHERE.
LONG TERM /SATURDAY THROUGH TUESDAY/
AS OF 205 PM EST TUESDAY: ANY NW FLOW SNOW ENDS BY SATURDAY MORNING
BUT WINDY TO BREEZY CONDITIONS CONTINUE THROUGH THE DAY. A SHORT
WAVE CROSSES THE AREA SUNDAY KEEPING LOW H5 HEIGHTS ACROSS THE AREA.
A SHORT WAVE RIDGE THEN BUILDS IN FOR MONDAY AND TUESDAY AHEAD OF A
TROUGH MOVING INTO THE CENTRAL CONUS. COLD AND DRY HIGH PRESSURE
BUILDS INTO THE AREA IN A COLD AIR DAMMING CONFIGURATION SUNDAY AND
REMAIN IN PLACE THROUGH TUESDAY. EXPECT DRY BUT COLD CONDITIONS EACH
DAY. HIGHS 5 TO 10 DEGREES BELOW NORMAL SATURDAY DROP TO 10 TO 15
DEGREES BELOW NORMAL SUNDAY, REMAIN NEARLY STEADY MONDAY, THEN RISE
BACK TO 5 TO 10 DEGREES BELOW NORMAL FOR TUESDAY. LOWS DROP INTO THE
TEENS AND 20S THROUGH THE PERIOD.
AVIATION /19Z TUESDAY THROUGH SUNDAY/
AT KCLT AND ELSEWHERE: MOSTLY DRY CONDITIONS EXPECTED THROUGH THE
18Z TAF PERIOD. WIND DIRECTION WILL BE NW ACROSS MOUNTAINS AND SW
EAST OF THE MOUNTAINS THROUGH THE PERIOD. WIND SPEEDS WILL RANGE
FROM ~4-9 KTS TODAY, BECOMING LIGHT TO CALM THIS EVENING INTO
TONIGHT. CALM WINDS AND LINGERING LOW-LEVEL MOISTURE WILL ALLOW FOR
ANOTHER ROUND OF LOW STRATUS AND DENSE FOG TO DEVELOP AGAIN
OVERNIGHT INTO WEDNESDAY MORNING SO HAVE LIFR TO IFR CIGS AND VSBYS
MENTIONED AT MOST TERMINALS. DID GO WITH VLIFR VSBYS AT KHKY AS
CONFIDENCE IS HIGHEST THAT THIS TERMINAL WILL SEE DENSE FOG. ANY FOG
THAT DEVELOPS SHOULD LIFT BETWEEN 14Z AND 16Z. A COLD FRONT WILL
APPROACH OUT OF THE WEST THROUGH TOMORROW MORNING BEFORE TRACKING
ACROSS THE FORECAST AREA TOMORROW AFTERNOON. HIGH-RES MODEL GUIDANCE
SOURCES ARE NOT IN GOOD AGREEMENT REGARDING THE ONSET TIMING OF RA
TOMORROW AFTERNOON/EVENING BUT OVERALL THEY DO AGREE THAT RAIN
SHOULD HOLD OFF UNTIL AFTER THE 18Z TAF FORECAST PERIOD. WIND SPEEDS
WILL GRADUALLY INCREASE AHEAD OF THE FRONT ON WEDNESDAY RANGING FROM
~7-10 KTS. SOME LOW-END GUSTS CANNOT BE ENTIRELY RULED OUT TOMORROW
AFTERNOON BUT DID NOT MENTION IN THE TAFS THIS CYCLE WITH THIS
POTENTIAL BEING TOWARDS THE END OF THE FORECAST PERIOD.
OUTLOOK: RAIN AND ASSOCIATED RESTRICTIONS MAY LINGER THROUGH
WEDNESDAY NIGHT. DRIER CONDITIONS ARE EXPECTED THURSDAY INTO THE
WEEKEND AS DRY HIGH PRESSURE BUILDS INTO THE REGION. COULD NOT RULE
OUT SOME PERIODIC CIG RESTRICTIONS THROUGH THE WEEKEND BUT IT SHOULD
BE DRY ENOUGH TO PROHIBIT FOG FORMATION.
GSP WATCHES/WARNINGS/ADVISORIES
GA...NONE.
NC...NONE.
SC...NONE.
SYNOPSIS...DEO
NEAR TERM...AR
SHORT TERM...RWH
LONG TERM...RWH
AVIATION...AR
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page