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000
FXUS62 KGSP 161144
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
644 AM EST MON DEC 16 2013

.SYNOPSIS...
HIGH PRESSURE WILL PERSIST ACROSS THE SOUTHEASTERN STATES OVER THE
NEXT FEW DAYS AND MAINTAIN DRY CONDITIONS THROUGH THE MIDDLE OF THE
WEEK. A FRONTAL SYSTEM WILL SLOWLY APPROACH THE NORTH CAROLINA
MOUNTAINS FRIDAY AND MAINTAIN A RELATIVELY WARM AND MOIST AIRMASS
THROUGHOUT THE WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...
630 AM UPDATE...FEW CHANGES. SKIES ARE VIRTUALLY CLEAR OVER THE CWFA
THOUGH SATELLITE FOG PRODUCT CONTINUES TO SUGGEST A FEW LOW CLOUDS
MAY BE VISIBLE ALONG THE TENN BORDER IN THE NRN MTNS...AND PATCHY
LOW STRATUS OR FOG IS PRESENT IN THE LITTLE TENN VALLEY. REVISED
MRNG TEMP TRENDS PER LATEST OBS...AND USING A MORE OPTIMISTIC
DIURNAL CURVE...WARMING UP FASTER GIVEN CLEAR SKIES EARLY ON.

TODAY AND TONIGHT...BROAD TROUGH PERSISTS OVER THE ERN CONUS...BUT
TROUGH SHIFTS SLIGHTLY EWD AS RIDGE AMPLIFIES OVER THE WEST. THE
ATMOSPHERE WILL CONTINUE TO BE DRY OVER OUR AREA WITH LITTLE FORCING
AND WEAK SFC PRESSURE GRADIENT. FLOW ACRS THE MTNS WILL REMAIN
GENERALLY WLY/UPSLOPE BUT EVEN LLVL MOISTURE IS NOT ENOUGH TO EXPECT
MUCH CLOUD COVER...ESPECIALLY GIVEN DIMINISHING LLVL RH AFTER
DAYBREAK. GFS/NAM BOTH SUGGEST SOME WEAK MIDLEVEL Q-VEC CONVERGENCE
ASSOC WITH A WEAK VORT MAX CROSSING THIS AFTN...PRODUCING FEW-SCT
HIGH CLOUDS FOR A TIME. TEMPERATURES WILL REMAIN AROUND NORMAL THIS
PERIOD. WINDS WILL REMAIN FAIRLY LIGHT IN GENERAL...BUT LLVL GRADIENT
TIGHTENS N OF THE REGION AS SFC LOW DROPS ACRS THE GREAT LAKES EARLY
TUE. HIGHER ELEVATIONS THUS WILL SEE BREEZY CONDITIONS CONTINUE
OVERNIGHT WITH AN UPTICK IN WINDS TOWARD DAWN TUE. GUSTS OF 25-30 KT
ARE LIKELY TO ACCOMPANY THESE WINDS ON RIDGE TOPS. LLVL MOISTURE
INCREASES SLIGHTLY TONIGHT ALSO...SO SKY COVER INCREASES NEAR THE
TENN BORDER AFTER SUNSET.

&&

.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 205 AM MONDAY...A STRONG SHORT WAVE WILL PASS BY TO THE NORTH
OF THE CWFA TUE AND EAST OF THE AREA TUE NITE. HEIGHTS RISE WED AND
WED NITE AS ZONAL FLOW DEVELOPS OVER THE ERN CONUS.

A DRY COLD FRONT CROSSES THE AREA TUESDAY WITH NWLY FLOW DEVELOPING
THRU TUE NITE. A COUPLE OF ROUNDS OF LOW LEVEL MOISTURE MOVE INTO
THE MTNS ON THE NWLY FLOW. RIGHT NOW...THE MOISTURE APPEARS TOO
SHALLOW FOR ANY NW FLOW PRECIP. HOWEVER...DO EXPECT CLOUDS MOVE MOVE
INTO THE TN BORDER COUNTIES...WITH SOME OF THE CLOUDS SPILLING OUT
ACROSS THE NC FOOTHILLS AND PIEDMONT FROM TIME TO TIME. IT WILL ALSO
BE BREEZY TO WINDY TUESDAY WITH WINDS REMAINING UP OVER THE MTNS TUE
NITE. HIGHS TUE WILL BE ABOUT 5 DEGREES ABOVE NORMAL WITH LOWS TUE
NITE NEAR TO SLIGHTLY BELOW NORMAL AS THERE IS NOT MUCH OF AN AIR
MASS CHANGE. HIGH PRESSURE BUILDS IN WED AND MOVES OFF THE CAROLINA
COAST WED NITE. THIS AIR MASS IS QUITE A BIT DRIER BUT NOT MUCH
WARMER. DESPITE THE RISING HEIGHTS AND DEVELOPING LIGHT SWLY FLOW...
HIGHS WED AND LOWS WED NITE WILL BE NEARLY STEADY FROM TUE AS LOW
LEVEL THICKNESSES REMAIN NEARLY STEADY.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 200 AM EST MONDAY...THE EXT RANGE HAS GOOD CONFIDENCE THIS
FCST PACKAGE AS THE EVOLUTION OF SPLIT FLOW PATTERN HAS BECOME
FAIRLY WELL AGREED UPON BTW THE OP MODELS. THE GFS IS STILL A BIT OF
AN OUTLIER AND HAS A UNIQUE JET MAX OVER TN AND NC MTNS
SAT/SUN...BUT BESIDES THAT...THE MODEL HAS GENERALLY COME IN LINE
WITH THE MORE DELIBERATE AND SLOWER ECMWF/CMC SOLNS.

AN UPPER LEVEL FLAT RIDGE WILL CROSS THE AREA THU...WHILE ATL
RIDGING IS MAINTAINED AT THE SFC. THIS WILL MAKE FOR A DRY FCST THU
AS MOIST RETURN FLOW BEGINS LATE IN THE DAY. ISENT LIFT WILL
INCREASE...ESP WEST...EARLY FRI AND WITH A REINFORCED MOIST AIRMASS
IN PLACE...WILL EXPECT -SHRA ACROSS THE SW NC MTNS COUPLED IN MECH
LIFT. MEANWHILE...UPPER HEIGHTS WILL BEGIN TO FALL AND ALIGN WITH A
SFC FRONT PUSHING INTO MIDDLE TN THROUGH THE DAY.

AS THE FRONT BECOMES MORE PARALLEL WITH THE UPPER FLOW...IT WILL
SLOW AS IT NEARS THE WRN ZONES AND LIKELY REMAIN WEST OF THE NC MTNS
THROUGH SAT. THE GFS AND THE ECWMF BOTH DEVELOP A WAVE TRAVERSING
THE FRONT AS IT PUSHES INTO THE CWFA SUN AND THIS COULD HELP SPAWN
SOME THUNDER ACROSS THE SRN ZONES SUN AFTERNOON...ALTHOUGH SBCAPE
AND ELCAPE WILL BE LOW END. POPS WERE MAINTAINED IN THE MID TO HIGH
END CHANCE RANGE CWFA/WIDE BEGINNING FRI NIGHT THROUGH SUN AS THE
SYSTEM WILL BE MAINTAINED WITH HIGH LLVL THETA/E AIR AND CONTINUOUS
LIFT AHEAD OF THE FRONT. SFC TEMPS WILL RESPOND WELL IN THIS PATTERN
AS SW/LY FLOW PERSISTS AND PERIODS OF INSOLATION ARE PROBABLE IN THE
PRE/FRONTAL ZONE. MAX TEMPS THU SHOULD BE ABOUT 6-8 DEGREES ABOVE
NORMAL...RISING TO AROUND 12-15 DEGREES ABOVE NORMAL OVER THE
WEEKEND. EXPECT THE SAME TREND IN MIN TEMPS WITH LOWS ONLY DROPPING
INTO THE M50S NON/MTNS AND L50S MTN VALLEYS BY SAT NIGHT.

&&

.AVIATION /12Z MONDAY THROUGH FRIDAY/...
AT KCLT AND ELSEWHERE...VFR AT ALL SITES THRU THE PERIOD UNDER VERY
DRY COLUMN. A PASSING SHORTWAVE DOES BRING ENOUGH ELEVATED MOISTURE
TO EXPECT SOME PATCHY MID-HIGH CLOUD THIS AFTERNOON. WINDS WILL
BECOME SWLY THIS MRNG AS HIGH PRESSURE BEGINS BUILDING IN FROM THE
GULF STATES. LEE TROUGHING MAY BACK WINDS SLIGHTLY FURTHER AT KHKY
AND KCLT. KAVL EXPECTED TO GO VRB AS IT OFTEN DOES WITH PREVAILING
SW FLOW. TONIGHT LIGHT SW BREEZES LOOK TO BE MAINTAINED BY
STRENGTHENING GRADIENT AS LOW PRESSURE ENTERS THE OHIO VALLEY. THIS
WILL REDUCE THE ALREADY LOW FOG RISK. DUE TO UPSLOPE AND A SHOT OF
LLVL MSTR ON THE W SIDE OF THE MTNS...A FEW MVFR LEVEL CLOUDS MAY
DRIFT ACRS KAVL LATE.

OUTLOOK..DRY/VFR CONDITIONS EXPECTED TO PERSIST THROUGH FRIDAY.

CONFIDENCE TABLE...

            11-17Z        17-23Z        23-05Z        05-11Z
KCLT       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KGSP       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KAVL       HIGH 100%     HIGH 100%     HIGH 100%     HIGH  93%
KHKY       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KGMU       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KAND       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%

THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE
HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE
FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)

WWW.WEATHER.GOV/GSP/AVIATION_TABLES

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.

&&

$$
SYNOPSIS...SBK
NEAR TERM...WIMBERLEY
SHORT TERM...RWH
LONG TERM...SBK
AVIATION...WIMBERLEY