Area Forecast Discussion
Issued by NWS Greer, SC

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000
FXUS62 KGSP 221411
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
ISSUED BY NATIONAL WEATHER SERVICE COLUMBIA SC
1011 AM EDT WED OCT 22 2014

.SYNOPSIS...
DRY HIGH PRESSURE WILL REMAIN IN CONTROL THROUGH EARLY NEXT WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...

AS OF 1000 AM EDT WEDNESDAY...MOSTLY CLEAR SKIES CONTINUE TO PREVAIL
ACROSS REGION WITH THE EXCEPTION OF THE HIGH TERRAIN WHERE UPSLOPE
FLOW INDUCED STRATUS PERSISTS.  AS PRESSURE GRADIENT FORCES REMAIN
ENHANCED ALONG WITH INCREASED MIXING...NORTHWESTERLY SURFACE WINDS
ARE STILL EXPECTED TO PICK UP WITH GUSTS LIKELY THROUGH MUCH OF THE
MORNING/AFTERNOON. TEMPERATURES ACROSS THE REGION ARE BEGINNING
TO RECOVER FROM COOLER/SLOW START THIS MORNING AS ABUNDANT
INCOMING RADIATION WARMS THE BL. OTHERWISE...CURRENT/DRY FORECAST
REMAINS ON TRACK WITH LATEST GUIDANCE THEREFORE NO SIGNIFICANT
CHANGES MADE WITH THIS UPDATE.

PREVIOUS DISCUSSION...

AS OF 230 AM...UPSTREAM MOISTURE REMAINS SHALLOW ACROSS THE OH
VALLEY AND ERN TN. DON/T SEE MUCH MORE THAN CLOUDS AFFECTING THE WRN
NC MTNS OVERNIGHT AS NW/LY MLVL FLOW REMAINS RATHER UN/ENERGETIC.
THERE IS STILL A GOOD H85 T/GRAD ATOP THE NC MTNS PROVIDING DOWNWARD
OMEGA AND MODERATE GUSTY CONDS OVER THE HIGHER TERRAIN. THE LLVL
FLOW REMAINS CHANNELED AND A GAP WIND HAS DEVELOPED INTO THE NRN
UPSTATE BRING LOW END GUSTS.

THE SYNOPTIC PATTERN WONT CHANGE MUCH DURING THE DAY...WITH THE ULVL
TROF SLOWLY PULLING NE WHILE A CP HIPRES SYSTEM CONTINUES TO CENTER
OVER THE ERN MIDWEST. WITH THE CP AIRMASS MIX...PWATS WILL DROP TO
ARND 60 PERCENT OF NORMAL OFFSETTING MUCH CLOUD DEVELOPMENT.
HOWEVER...SCT/BKN CU AND STCU WILL CONTINUE ACROSS THE FAR WRN
ZONES. THE AIRMASS MIX WILL ALSO KEEP LLVL THICKNESSES SHALLOW AND
MAX TEMPS WILL BE HELD ABOUT 5 DEGREES BELOW NORMAL NON/MTNS AND
ARND 8-10 DEGREES BELOW NORMAL MTN VALLEYS WHERE H85 CAA REMAINS THE
STRONGEST. THE FAR SRN ZONES SHOULD SEE MAXES NEAR NORMAL IN LESS
AIRMASS MIXING AND GOOD INSOL.

THE UPPER PATTERN REMAINS ALIGNED NW/LY OVERNIGHT WITHIN A TIGHT
HEIGHT FIELD...HOWEVER THE LLVLS WILL SEE A GENERAL BROADENING OF
THE P/GRAD AS HIGH PRESSURE CONTINUES TO RIDGE IN FROM THE NW. THIS
WILL ALLOW WINDS AND THE SFC THERMAL LAYER TO DECOUPLE A LITTLE AND
MINS WILL DROP A COUPLE DEGREES BELOW NORMAL. NO FROST CONCERNS
OVERNIGHT AS LLVL MIXING REMAINS OVER THE NW MTN ZONES...THE SRN MTNS
COULD SEE PATCHY FROST BUT THESE COUNTIES HAVE ALREADY HAD A FREEZE
THIS FALL.

&&

.SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/...
AS OF 325 AM WEDNESDAY...TYPICALLY BENIGN MID-AUTUMN WEATHER WILL
PERSIST INTO THE WEEKEND...AS UPPER LOW SPINS OFF THE NORTHEAST
COAST...AND THE MEAN EASTERN LONG WAVE TROUGH IS REINFORCED BY A
SHORT WAVE DIVING OUT OF THE CORN BELT REGION THU NIGHT/FRIDAY.
PERSISTENT NW FLOW SHOULD RESULT IN PERIODS OF STRATOCU ACROSS THE
WESTERN MTNS THROUGH THE PERIOD...BUT MOISTURE IS EXPECTED TO REMAIN
TOO SHALLOW TO SUPPORT UPSLOPE SHOWERS. GOOD RADIATIONAL COOLING
CONDITIONS FRI NIGHT WILL LIKELY RESULT IN AT LEAST PATCHY FROST AND
POCKETS OF FREEZING TEMPS IN THE MTNS. HOWEVER...MTN ZONES FOR WHICH
FROST/FREEZE PRODUCTS ARE STILL BEING ISSUED WILL BE THE LEAST
LIKELY TO GET COLD...AS NW FLOW MAY RESULT IN PERSISTENT UP-VALLEY
WINDS OVERNIGHT...ESP IN THE FRENCH BROAD VALLEY. OTHERWISE...TEMPS
WILL BE NEAR NORMAL THROUGH THE PERIOD.

&&

.LONG TERM /FRIDAY THROUGH TUESDAY/...
AS OF 330 AM WEDNESDAY...GLOBAL MODEL GUIDANCE CONTINUES TO DEPICT A
PATTERN CHANGE DURING THE MEDIUM RANGE...AS A SERIES OF STRONG SHORT
WAVE TROUGHS INVADE THE WEST COAST. THIS RESULTS IN ESTABLISHMENT OF
A LONG WAVE RIDGE ACROSS THE CENTRAL CONUS...WHICH PROGRESSES TO THE
EASTERN STATES BY THE END OF THE PERIOD. NEVERTHELESS...THIS PATTERN
WILL SUPPORT PERSISTENCE OF GENERALLY DRY HIGH PRESSURE ACROSS OUR
REGION DURING MUCH OF THE PERIOD. CHANCES FOR A FROPA MAY INCREASE
BY THE END OF THE PERIOD...AS THERE ARE SIGNS THE RIDGE MAY BEGIN TO
FLATTEN DURING THIS TIME. TEMPS WILL LIKELY CREEP ABOVE NORMAL BY
DAY 7...AS DEEP BUT DRY SW FLOW GRADUALLY BECOMES ESTABLISHED.

&&

.AVIATION /14Z WEDNESDAY THROUGH SUNDAY/...
AT KCLT AND ELSEWHERE...VFR CONDS AT ALL TERMINALS THROUGH THE
PERIOD. MODERATE GRADIENT FLOW AND H85 CAA WILL PREVAIL THIS
AFTERNOON WITH WINDS REMAINING CHANNELED UP THE FRENCH BROAD
VALLEY. NON/MTN SITES WILL MAINTAIN NNW/LY WINDS WITH A LOW END GUST
POTENTIAL THIS AFTERNOON THRU 00Z MAINLY AT AT KCLT AND KHKY. KAVL
WILL LIKELY SEE HIGHER GUSTS ARND 25 KTS THIS AFTERNOON. BELOW
NORMAL PWATS WILL MIX IN THROUGHOUT THE DAY KEEPING SKIES CLEAR WITH
PERHAPS FEW/SCT FAIR WX CU AND SOME THIN CI AT KAVL AND KHKY.

OUTLOOK...QUIET WEATHER WILL CONTINUE ACRS THE REGION...AS DEEP
LAYER RIDGING SETTLES IN THRU THIS WEEKEND.

CONFIDENCE TABLE...

            10-16Z        16-22Z        22-04Z        04-10Z
KCLT       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KGSP       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KAVL       MED   65%     HIGH 100%     HIGH 100%     HIGH 100%
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...JDL
NEAR TERM...SBK/CDG
SHORT TERM...JDL
LONG TERM...JDL
AVIATION...SBK






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