Area Forecast Discussion
Issued by NWS Greer, SC

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FXUS62 KGSP 220727
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
327 AM EDT FRI MAY 22 2015

.SYNOPSIS...
DRY CANADIAN HIGH PRESSURE WILL BUILD OVER THE CAROLINAS AND
NORTHEAST GEORGIA TODAY AND REMAIN THROUGH THE HOLIDAY WEEKEND. A
SOUTHERLY FLOW OF MOISTURE AROUND A BERMUDA HIGH PRESSURE WILL
GRADUALLY RETURN NEXT WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 230 AM...A BROAD UPPER LEVEL TROF AXIS WILL BEGIN TO SHIFT
EAST...WITH THE AXIS FROM THE APPALACHIANS TODAY TO THE EAST COAST
TONIGHT. THIS WILL ALLOW HEIGHTS TO START RISING ATOP THE CWFA...AND
MAKE FOR MOSTLY CLEAR SKIES. AT THE SFC...A LARGE AREA OF DRY HIGH
PRES WILL CONTINUE TO BUILD IN ACRS A HUGE PORTION OF THE EASTERN
CONUS. LLVL THICKNESSES WILL SUPPORT TEMPS A CATEGORY OR TWO BELOW
NORMAL WITH LOW HUMIDITY AND LIGHT WINDS...MAKING FOR A VERY
PLEASANT DAY. MIN TEMPS TONIGHT WILL BE ABOUT A CATEGORY BELOW
NORMAL.

&&

.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 150 AM FRIDAY...AN UPPER LEVEL RIDGE BUILDS ACROSS THE SERN US
THRU THE PERIOD. AT THE SFC...THE CENTER OF HIGH PRESSURE MOVES FROM
THE MID ATLANTIC STATES OFF SHORE DURING THE DAY SAT...BUT REMAINS
RIDGED ACROSS THE AREA. THE CENTER SLOWLY MOVES EAST INTO THE
ATLANTIC THRU THE REST OF THE PERIOD...BUT REMAINS RIDGED INTO THE
AREA DURING THIS TIME. THERE IS NO INSTABILITY ACROSS THE AREA
DURING THE PERIOD AND DEEP MOISTURE REMAINS OFF TO THE WEST.
THEREFORE...THE DRY FCST WILL CONTINUE. HOWEVER...THERE COULD BE
SOME CLOUDS EARLY SAT AND SUN AS WEAK UPSLOPE FLOW INTERACTS WITH
SOME LINGERING LOW LEVEL MOISTURE. BETTER CHC OF CLOUDS SUN
AFTERNOON AND NITE AS LOW LEVEL MOISTURE AND UPSLOPE FLOW INCREASE.
HIGHS NEAR TO A LITTLE ABOVE NORMAL SAT RISE A COUPLE OF DEGREES ON
SUNDAY. LOWS A FEW DEGREES ABOVE NORMAL SAT NITE RISE A FEW DEGREES
ON SUN NITE.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 325 AM FRI...THE PATTERN TAKES ON A DEFINITE SUMMER FEEL THRU
MUCH OF THE MEDIUM RANGE WITH RIDGING SFC AND ALOFT. THE RIDGE AXIS
IS FAR ENUF EAST AND THE SFC RIDGE AXIS IS FAR ENUF SOUTH FOR A
MOIST SWLY FLOW TO DEVELOP ACROSS THE AREA MON THRU WED. INSTABILITY
AND MOISTURE INCREASE EACH DAY BRINGING AN INCREASE IN DIURNAL
CONVECTIVE COVERAGE EACH DAY. STILL...BEST PRECIP CHC EACH DAY WILL
BE OVER THE MTNS FARTHER FROM THE RIDGE AXES CREATING BETTER
MOISTURE AND HIGHER INSTABILITY. SOME DIFFERENCES CREEP IN ON THU.
THE ECMWF KEEPS THE UPPER RIDGE STRONGER DAMPENING THE APPROACHING
SHORT WAVE AND MOVING IT FARTHER NORTH. THE GFS HAS A STRONGER SHORT
WAVE WHICH KNOCKS DOWN THE RIDGE AND MOVES ACROSS THE AREA.
THEREFORE...THE ECMWF HAS LESS CONVECTIVE COVERAGE WHILE THE GFS IS
HIGHER. HAVE GONE WITH A BLEND WHICH KEEPS COVERAGE SIMILAR TO WED.
TEMPS START OUT ABOVE NORMAL AND RISE A COUPLE OF DEGREES EACH DAY.

&&

.AVIATION /08Z FRIDAY THROUGH TUESDAY/...
AT KCLT AND ELSEWHERE...DRY HIGH PRES WILL BUILD INTO THE
REGION...MAKING FOR DIMINISHING WIND AND CLEARING SKIES THIS MORNING
THRU MIDDAY. A FEW CIRRUS THIS AFTN POSSIBLE...WITH LIGHT WINDS
BECOMING VARIABLE.

AT KAVL...MOISTURE WILL CONTINUE TO WORK UP THE VALLEY WITHIN
NORTHWESTERLY FLOW...RESULTING IN PERIODS OF MVFR CIGS. DRIER AIR
WILL EVENTUALLY ARRIVE BY LATE MORNING...WITH JUST A FEW CIRRUS FROM
MIDDAY ONWARD. WINDS ARE GUSTING OUT OF THE NORTH AS USUAL BEHIND
COLD FRONTS...AND GUIDANCE GRADUALLY WEAKENS THE WINDS AND LOSES THE
GUSTS BY LATE MORNING. WINDS BECOME LIGHT BY THIS EVENING.

OUTLOOK...DEEP HIGH PRESSURE WILL SETTLE OVER THE REGION...THEN
SHIFT EAST EARLY NEXT WEEK...ALLOWING MOISTURE TO GRADUALLY RETURN
OUT OF THE SOUTH. CONDITIONS SHOULD REMAIN GENERALLY FAIR THROUGH
THE PERIOD.

CONFIDENCE TABLE...

            07-13Z        13-19Z        19-01Z        01-06Z
KCLT       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KGSP       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KAVL       MED   79%     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...RWH
NEAR TERM...ARK
SHORT TERM...RWH
LONG TERM...RWH
AVIATION...ARK


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