Area Forecast Discussion
Issued by NWS Greer, SC

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS62 KGSP 191528
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
1128 AM EDT SUN OCT 19 2014

.SYNOPSIS...
CANADIAN HIGH PRESSURE WILL BUILD ACROSS THE REGION THROUGH MONDAY.
A WEAK COLD FRONT IS EXPECTED TO CROSS THE AREA TUESDAY...BRINGING
SMALL CHANCES OF RAIN TO SOME OF THE REGION. DRY AND MOSTLY SUNNY
WEATHER WILL PREVAIL THE REST OF THE WEEK WITH TEMPERATURES TYPICAL
FOR THE SEASON.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 AM...CLOUDS OVER THE NC MOUNTAINS CONTINUE TO MIX OUT
AROUND THE EDGES...SO THE FCST LOOKS LIKE IT IS IN GOOD SHAPE. SOME
TEMPS WERE RUNNING A BIT AHEAD OF THE FCST...SO THE TREND WILL BE
UPDATED...BUT THE HIGH TEMP STILL LOOKS OKAY.

REMAINDER OF PREVIOUS DISCUSSION...
NW FLOW/UPSLOPE MOISTURE WILL GRADUALLY BECOME MORE SHALLOW WITH
TIME THIS MORNING...AS POTENT SHORT WAVE TROUGH MOVES SWIFTLY OFF
THE CAROLINA COAST THIS MORNING. THE RESULT WILL BE A GRADUAL
RETREAT AND DIMINISHING OF CLOUD COVER ACROSS THE MTNS THROUGHOUT
THE MORNING...WITH SUNNY SKIES EXPECTED IN ALL AREAS BY EARLY
AFTERNOON. UNDER HEIGHTS SLIGHTLY BELOW SEASONAL NORMS...MAX TEMPS
WILL BE ABOUT A CATEGORY BELOW CLIMO THIS AFTERNOON.

BY THE END OF THE DAY...LOW-MID TROPOSPHERIC FLOW WILL RETURN TO
SOUTHERLY...IN RESPONSE TO ANOTHER SHORT WAVE DIGGING STRONGLY OUT
OF THE NORTHERN PLAINS. THIS...ALONG WITH CIRRUS ATTENDING
ASSOCIATED UPPER JET MAX...ARE THE FLIES IN THE OINTMENT IN TERMS OF
THE QUALITY OF RADIATIONAL COOLING THAT WILL EXIST ACROSS THE AREA
TONIGHT. SOME OF THE TRADITIONAL COLD SPOTS ACROSS THE NC MTNS WILL
NO DOUBT SEE /FROSTY/ TEMPS. HOWEVER...THE FROST/FREEZE PROGRAM HAS
BEEN SHUT OFF FOR THE SEASON IN THE AREAS MOST LIKELY TO SEE FROST
OR A LIGHT FREEZE TONIGHT...SO NO PRODUCTS WILL BE ISSUED.
OTHERWISE...MIN TEMPS ARE EXPECTED TO RANGE FROM 5-10 DEGREES BELOW
CLIMO.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 300 AM SUNDAY...UPPER TROUGH DIGS INTO THE ERN CONUS MONDAY
WITH HEIGHTS CONTINUING TO FALL INTO THE MIDWEEK...AND A CLOSED LOW
DEVELOPING WITHIN THE TROUGH. TEMPS WILL REBOUND A BIT ON MONDAY IN
SW FLOW. A WEAK COLD FRONT WILL PUSH INTO THE REGION TUESDAY BUT THIS
WILL HAVE LITTLE IMPACT ON THICKNESS VALUES...AND THE SHIFT TO NW
FLOW ACRS THE CWFA LOOKS TO HAVE A SLIGHT WARMING EFFECT. MOISTURE
DURING THE PERIOD IS LIMITED TO THE LOW LEVELS...AND THOUGH WELL
DEFINED LOBES OF VORTICITY PASS OVER THE FA MONDAY NIGHT AND TUESDAY
NIGHT THE MODELS ONLY SUPPORT PRECIP WHERE THESE FEATURES ENHANCE THE
FORCING PROVIDED BY CAA AND/OR HIGH-ELEVATION INSTABILITY. WE WILL
FEATURE LOW TENN BORDER POPS MONDAY NIGHT EXPANDING TO THE REST OF
THE MTNS AND NRN FOOTHILLS/PIEDMONT AREAS TUE...BEFORE THEY AGAIN
RETREAT TO THE BORDER AREA TUE NIGHT. THIS FOLLOWS THE COMBINED
TRENDS OF THE FORCING MECHANISMS DESCRIBED ABOVE. TEMPS WILL BE NEAR
CLIMO...WITH MINS LOOKING TOO WARM FOR FROST CONCERNS.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 315 AM SUNDAY...UPPER LOW WILL CONTINUE TO SPIN OVER THE
MID-ATLANTIC COAST WED-THU BEFORE LIFTING OFF TOWARD THE NORTHEAST.
A NARROW RIDGE WILL BUILD IN BEHIND IT...WITH A MORE SUBSTANTIAL
RIDGE THEN BUILDING OVER THE ROCKIES. THE TWO RIDGES EVENTUALLY MERGE
LEAVING MOST OF THE CONUS DRY AND WITH SETTLED WEATHER BY NEXT
WEEKEND...THOUGH THE GFS/EC/GEFS ALL DO ALLOW A SHORTWAVE TROUGH TO
SQUEEZE BETWEEN THOSE RIDGES AND THEN TO CUT OFF AND LINGER OVER THE
GULF COAST SATURDAY. FOR NOW WPC FAVORS A SOLUTION WITH THE DOMINANT
RIDGE. AS FOR OUR AREA...AT THE SFC CONTINENTAL HIGH PRESSURE WILL
REINFORCE DRY NORTHERLY FLOW INTO THE CWFA THROUGH THE MEDIUM RANGE
PERIOD. EVEN IF THE CUTOFF LOW FORMS IT DOES NOT APPEAR TO HAVE AN
IMPACT HERE UNTIL AFTER THE END OF DAY 7. EXCEPT FOR SOME VERY LOW NW
FLOW POPS IN THE NRN MTNS EARLY WED...NO PRECIP WILL BE ADVERTISED.
TEMPS WILL SUBTLY WARM THRU THE PERIOD AS THE CONTINENTAL AIRMASS
MODIFIES. THERE HOWEVER MAY BE SOME FROST CONCERNS IN THE MTNS THU
MRNG UNDER EXCELLENT RADIATIVE CONDITIONS.

&&

.AVIATION /16Z SUNDAY THROUGH THURSDAY/...
AT KCLT AND ELSEWHERE (EXCEPT KAVL)...ESSENTIALLY A WIND FORECAST-
ONLY DURING THE NEXT 24 HOURS...AS MUCH DRIER AIR PERSISTS...
ENSURING VFR/SKC CONDITIONS THROUGH THE PERIOD. WINDS WILL GENERALLY
REMAIN N/NW AT 5-7 KTS AT MOST TERMINALS...BEFORE BECOMING CALM OR
LIGHT/VRBL DURING THE AFTERNOON...THEN POSSIBLY BECOMING LIGHT
SOUTHERLY BY EVENING.

AT KAVL...NW/UP-VALLEY WINDS AT 8-12 KTS WILL CONTINUE THROUGH THE
DAY...WITH OCCL GUSTS IN THE TEENS LIKELY FROM MID-MORNING INTO
EARLY AFTERNOON. MVFR STRATOCU SHOULD SCATTER OUT BY 15Z OR
SO...WITH VFR CONDITIONS EXPECTED THROUGH AT LEAST THE EVENING. A
DEVELOPING SOUTHERLY FLOW MAY SUPPORT SHALLOW LOW LEVEL MOISTURE
ACROSS THE MTNS LATE TONIGHT/EARLY MONDAY. THIS COULD RESULT IN SOME
FOG AND/OR VISBY RESTRICTIONS AT KAVL...BUT THIS IS VERY UNCERTAIN
ATTM.

OUTLOOK...DRY HIGH PRES WILL GENERALLY DOMINATE THROUGH TUESDAY.
ANOTHER ROUND OF GUSTY NW WINDS AND MOUNTAIN STRATOCU WILL BE
POSSIBLE BEHIND ANOTHER (MOSTLY DRY) COLD FRONT LATE TUE INTO EARLY
WED. OTHERWISE...VFR CONDITIONS SHOULD PREDOMINATE INTO LATE WEEK.

CONFIDENCE TABLE...

            15-21Z        21-03Z        03-09Z        09-15Z
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 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...WIMBERLEY
NEAR TERM...JDL/PM
SHORT TERM...WIMBERLEY
LONG TERM...WIMBERLEY
AVIATION...JDL





USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.