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000
FXUS62 KGSP 241430
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
1030 AM EDT FRI MAY 24 2013

.SYNOPSIS...
AN UPPER LEVEL TROUGH WILL SWING THROUGH THE REGION TODAY...BRINGING
COOLER AND DRIER CONDITIONS FOR THE WEEKEND. TEMPERATURES WILL
MODERATE BY THE BEGINNING OF NEXT WEEK...WITH A CHANCE OF AFTERNOON
SHOWERS AND THUNDERSTORMS EACH DAY CONCENTRATED OVER THE MOUNTAINS.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF MID MORNING...KMRX RADAR SHOWS LIGHT PRECIP ECHOES ON THE WANE
ALONG THE TN BORDER...SO IT WOULD APPEAR THAT ANY NW FLOW SHOWER
ACTIVITY IS ON SCHEDULE TO END DURING THE NEXT HOUR. SOME CLOUDINESS
WILL CONTINUE OVER THE HIGHER TERRAIN INTO THE EARLY AFTERNOON. THE
ONLY OTHER FEATURE OF INTEREST IS A PATCH OF CLOUDS MOVING ACROSS
METRO CLT...BUT THAT SHOULD ALSO MOVE OFF TO THE SOUTHEAST. TEMPS
LOOK OKAY FOR NOW...NO CHANGES TO THE HIGHS.

REMAINDER OF PREVIOUS DISCUSSION...

TODAY...DRY HIGH PRES WILL BEGIN TO CONTINUE BUILD INTO THE AREA
FROM THE NW. MOST OF THE GUIDANCE...THE NAM IN PARTICULAR...INDICATE
BREEZY TO WINDY CONDITIONS ACRS THE CWFA. IN FACT...THE HIGH TERRAIN
AND SOME OF THE VALLEYS WHERE A GAP WIND WILL SET UP MAY APPROACH
WIND ADV CRITERIA...MAINLY DURING THE MORNING HOURS. CONFIDENCE NOT
HIGH ENUF TO GO WITH A WIND ADV IN THE MTNS. ELSEWHERE...BREEZY
CONDITIONS WARRANTS CAUTION ON AREA LAKES. TEMPS WILL BE BELOW
NORMAL UNDER SUNNY TO MOSTLY SUNNY SKIES.

TONIGHT...THE SFC HIGH WILL STILL BE CENTERED TO OUR NW...SO MIXING
IS EXPECTED TO CONTINUE THRU THE NIGHT. CLEAR SKIES AND CAA WILL
ALLOW TEMPS TO DROP INTO THE 30S IN THE MTNS AND 40S ACRS MOST OF
THE PIEDMONT. PATCHY FROST IS POSSIBLE IN THE SHELTERED
VALLEYS...BUT WIDESPREAD FROST IS NOT EXPECTED DUE TO THE MIXING
ACRS THE HIGH TERRAIN.

&&

.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 300 AM FRIDAY...GENERALLY FAIR WEATHER SATURDAY THROUGH SUNDAY
NIGHT. CLOUD COVER WILL INCREASE SATURDAY NIGHT...WITH VARIABLY
CLOUDY CONDITIONS EXPECTED INTO SUNDAY NIGHT. THIS WILL BE THE
RESULT OF WARM ADVECTION ON THE BACK SIDE OF A STRONG LONG WAVE
TROUGH. OVERALL THE FORCING LOOKS WEAK AND MOST OF WHAT WE SHOULD
SEE DURING THIS PERIOD WILL BE AC/SC AND PERHAPS A FEW AREAS OF
HIGH-BASED SPRINKLES OR LIGHT SHOWERS...PARTICULARLY SATURDAY NIGHT.
MAX TEMPS SATURDAY WILL BE A COUPLE CATEGORIES BELOW
NORMAL...REBOUNDING A FEW DEGREES ON SUNDAY.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 240 AM FRIDAY...THE EXTENDED FORECAST LOOKS GOOD AND NO MAJOR
CHANGES HAVE BEEN MADE TO THE GRIDS. THE 00 UTC GFS AND YDAYS 12 UTC
ECMWF ARE IN GOOD AGREEMENT IN GRADUALLY BUILDING A LONG WAVE RIDGE
ACROSS THE LOWER MS RIVER VALLEY AND DEEP SOUTH STATES THROUGH THE
PERIOD. WE WILL START OUT THE PERIOD UNDER NW FLOW ON THE BACK SIDE
OF A LARGE LONG WAVE RIDGE CENTERED OVER THE WRN ATLANTIC. THE
MODELS HAVE QUITE A BIT OF MID AND UPPER LEVEL MOISTURE ON THE BACK
SIDE OF THE TROUGH...THE RESULT OF LOW AND MID LEVEL ISENTROPIC
UPGLIDE. STILL...THE SFC DEWPOINTS ARE LOW AND PCPN CHANCES MONDAY
SHOULD MAINLY BE CONFINED TO SPRINKLES OR LIGHT HIGH-BASED SHOWERS
OVER THE MTNS. TUE THROUGH THU BNDRY LAYER MOISTURE INCREASES AS THE
SFC RIDGE AXIS MOVES OFF THE COAST. THE GFS HAS THE BEST INSTABILITY
BY FAR OVER THE MOUNTAINS TUE AND WED...WITH A LITTLE MORE DRYING ON
FRI. AT THIS POINT LOW CHANCE POPS OVER THE MTNS AND SLIGHT CHANCE
POPS ELSEWHERE ALL THREE DAYS STILL LOOKS GOOD. I DID NUDGE TEMPS UP
A LITTLE TUE. I THINK WED AND THU ARE PROBABLY A LITTLE TOO
COOL...BUT I/LL LEAVE THAT FOR THE DAY SHIFT TO DECIDE.

&&

.AVIATION /15Z FRIDAY THROUGH TUESDAY/...
AT KCLT...VFR WITH SOME LINGERING MID CLOUDS THRU ABOUT 14Z. A NW
WIND EXPECTED THRU THE PERIOD...INCREASING INTO THE 10-15 KT RANGE
BY MID MORNING...WITH GUSTS IN THE 20-25 KT RANGE EXPECTED THRU THE
AFTN. WINDS DIMINISH AROUND SUNSET THIS EVENING.

AT KAVL...STRONG CHANNELED VALLEY WINDS WILL CONTINUE THRU THE DAY.
GENERALLY SUSTAINED 15-20 KTS AND GUSTS POSSIBLY IN THE 30-35 KT
RANGE. SOME MOISTURE WILL CONTINUE TO WORK UP THE VALLEY THRU ABOUT
MID MORNING...WITH ANY CIGS EXPECTED TO BE VFR. HOWEVER...BRIEF
PERIODS OF MVFR CIGS ARE POSSIBLE. SO WILL HAVE TEMPO FOR A COUPLE
HOURS. WINDS WILL BEGIN TO DIMINISH AFTER SUNSET THIS EVENING.

ELSEWHERE...VFR CONDITIONS ARE EXPECTED AT ALL OTHER TAF SITES THRU
THE PERIOD. WINDS WILL BE THE MAIN CONCERN TODAY. EXPECTING ALL
SITES TO HAVE WINDS IN THE 10-12KT RANGE WITH GUST APPROACHING 25KTS
FROM LATE MORNING THRU THE AFTN.

OUTLOOK...WITH DRY HIGH PRES DOMINATING THE WEATHER ACRS THE REGION
THRU THE WEEKEND...NO SIGNIFICANT AVIATION CONCERNS ARE EXPECTED.

CONFIDENCE TABLE...

            14-20Z        20-02Z        02-08Z        08-14Z
KCLT       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KGSP       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KAVL       HIGH  99%     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

&&

.FIRE WEATHER...
IT WILL BE WINDY OVER THE MOUNTAINS AND BREEZY OVER MUCH OF THE REST
OF THE FORECAST AREA TODAY. AFTERNOON MINIMUM RELATIVE HUMIDITY
VALUES WILL FALL TO BETWEEN 25 AND 30 PERCENT. WITH RECENT
WIDESPREAD RAINFALL...FUEL MOISTURE VALUES ARE GENERALLY STILL
HIGH...AND WE DO NOT ANTICIPATE NEEDING ANY FIRE DANGER PRODUCTS
TODAY. IF ANY LAND MANAGEMENT OFFICIALS THINK THAT A FIRE DANGER
STATEMENT IS WARRANTED PLEASE CONTACT OUR OFFICE.

&&

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

&&

$$
SYNOPSIS...LEV
NEAR TERM...ARK/PM
SHORT TERM...MCAVOY
LONG TERM...MCAVOY
AVIATION...ARK
FIRE WEATHER...