Area Forecast Discussion
Issued by NWS Greer, SC

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000
FXUS62 KGSP 241106
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
706 AM EDT SUN MAY 24 2015

.SYNOPSIS...
DRY CANADIAN HIGH PRESSURE WILL REMAIN ATOP THE REGION TODAY. THE
HIGH TAKES ON A SUMMERTIME BERMUDA HIGH PATTERN ON MEMORIAL DAY AND
REMAINS THERE THROUGH THE WEEK. A MOIST SOUTHERLY FLOW DEVELOPS WITH
INCREASING CHANCES FOR CONVECTION.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 700 AM...FCST IS ON TRACK. I DID REMOVE THE FOG FROM THE MTN
VLYS...AS NO FOG HAS DEVELOPED. ALSO BUMPED UP SKY COVER SLIGHTLY TO
ACCOUNT FOR THE INCREASED CIRRUS ON THE IR SAT IMAGERY.

AS OF 230 AM...A LARGE UPPER RIDGE WILL REMAIN OVER THE AREA
TODAY...WHILE THE CENTER OF THE SFC RIDGE SETS UP OFF THE MID
ATLANTIC COAST. THE INCREASING SOUTHEASTERLY LLVL FLOW ATOP THE CWFA
SHUD BEGIN TO TRANSPORT SOME SHALLOW ATLANTIC MOISTURE INTO THE
AREA. HOWEVER...MID LVL SUBSIDENCE WILL RESULT IN ANOTHER DRY DAY.
THICKNESSES WILL BE SIMILAR TO YESTERDAY...WITH MAX TEMPS ABOUT A
CATEGORY ABOVE NORMAL.

TONIGHT...MODELS IN GOOD AGREEMENT ON A SHALLOW MOIST LAYER REACHING
THE UPPER SAVANNAH VALLEY AND SOUTHERN BLUE RIDGE ESCARPMENT
OVERNIGHT. SO EXPECT STRATUS TO DEVELOP...AT LEAST ACRS THE WESTERN
HALF OF THE CWFA BY DAYBREAK MONDAY. MOST OF THE GUIDANCE TRIES TO
SQUEEZE OUT A FEW LIGHT SHWRS ALONG THE ESCARPMENT WITHIN THE
SOUTHEASTERLY UPSLOPE FLOW. HOWEVER...FCST SNDGS SHOW THE DEPTH OF
THE NEAR-SATURATED LAYER TO BE VERY SHALLOW. SO WILL GO WITH A DRY
FCST OVERNIGHT. TEMPS WILL BE A COUPLE CATEGORIES ABOVE NORMAL
WITHIN THE SE FLOW AND INCREASING CLOUDS LATE.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 155 AM SUNDAY...THE UPPER RIDGE AXIS OVER THE AREA SLIDES TO
THE COAST ON MONDAY ALLOWING A SWLY FLOW TO DEVELOP. THIS PATTERN
HOLDS ON TUE WITH A SERIES OF WEAK SHORT WAVES SLIDING THRU THE FLOW
AND OVER OR NEAR THE CWFA. AT THE SFC...RIDGING FROM THE BERMUDA
HIGH WEAKENS ALLOWING A LOW LEVEL SLY TO SWLY FLOW TO DEVELOP AS
WELL. THIS WILL HELP CREATE A DEEP PLUME OF GULF MOISTURE WHICH
MOVES INTO THE AREA...ESPECIALLY THE WRN CWFA DURING THIS PERIOD.
THEREFORE...EXPECT SCT CONVECTION TO DEVELOP OVER THE WRN CWFA
MONDAY DIMINISHING TO NO CONVECTION OVER THE I-77 CORRIDOR. PRECIP
CHC INCREASES ACROSS THE BOARD ON TUE AS MOISTURE AND FORCING
INCREASE. ALTHOUGH THERE WILL BE A DIURNAL TREND TO THE CONVECTIVE
COVERAGE...EXPECT AT LEAST SOME SHRA TO LINGER THRU THE NITE GIVEN
THE COPIOUS LOW LEVEL MOISTURE AND GENERAL UPSLOPE FLOW. THE THREAT
OF SEVERE WEATHER WILL BE MITIGATED BY POOR LAPSE RATES AND
RELATIVELY WEAK INSTABILITY. ABOVE NORMAL TEMPS MON WILL REMAIN
NEARLY STEADY OR RISE A COUPLE OF DEGREES TUE DEPENDING ON LOCATION.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 315 AM SUNDAY...THE UPPER RIDGE AXIS OVER THE EAST COAST
WEAKENS AND ALLOWS A SERIES OF SHORT WAVES TO MOVE OVER OR NEAR THE
AREA THRU THE PERIOD. AT THE SFC...A BERMUDA HIGH REMAINS IN PLACE
OVER THE AREA IN A PATTERN MORE TYPICAL OF SUMMER. THIS KEEPS A
MOIST SWLY FLOW OVER THE AREA. THIS PATTERN WILL LEAD TO MAINLY
DIURNAL CONVECTION EACH DAY...POSSIBLY LINGERING THRU THE NITE WED
NITE. COVERAGE WILL LIKELY BE HIGHER WED AND THU THEN ON FRI AND
SAT...DUE TO GREATER MOISTURE EARLY IN THE PERIOD. TEMPS WILL REMAIN
ABOVE NORMAL THRU THE PERIOD.

&&

.AVIATION /11Z SUNDAY THROUGH THURSDAY/...
AT KCLT...NO MAJOR CHANGES TO THE THINKING FOR THE 12Z TAFS. AS HIGH
PRESSURE SLIDES EAST...SOUTHEASTERLY FLOW WILL INCREASE A BIT TODAY
COMPARED TO YESTERDAY. WINDS WILL START OUT CALM OR LGT SE...THEN
INCREASE TO THE 8-12 KT RANGE WITH A FEW LOW-END GUSTS POSSIBLE THIS
AFTN. THERE WILL BE A FEW WISPS OF THIN CIRRUS THRU THE DAY...WITH A
FEW FAIR WX CUMULUS WITH BASES AROUND 5000 FT. SOME LLVL MOISTURE
WILL INCREASE OFF THE ATLANTIC...WITH GUIDANCE SHOWING LOW CIGS
DEVELOPING TO THE WEST OF KCLT BEFORE DAYBREAK. GUIDANCE IN GOOD
AGREEMENT THAT IT SHUD REMAIN WEST OF THE TERMINAL THRU 12Z...SO NO
LOW CIGS WILL BE SHOWN IN THE 12Z TAF.

ELSEWHERE...SE WINDS WILL PICK UP TO THE 8-12 KT RANGE UNDER A FEW
FAIR WX. A FEW FAIR WX CUMULUS CLOUDS WITH BASES IN THE 4500 TO 6000
FT RANGE ARE EXPECTED THIS AFTN. MODELS IN GOOD AGREEMENT THAT IFR
OR LOW MVFR CIGS WILL DEVELOP BEFORE DAYBREAK MONDAY...AS THE
SOUTHEASTERLY LLVL FLOW TRANSPORTS ATLANTIC MOISTURE INTO THE AREA.
THE STRATUS MAY OR MAY NOT MAKE IT TO KHKY. SO WILL LEAVE OUT OF THE
12Z TAF THERE.

OUTLOOK...MOISTURE WILL GRADUALLY RETURN OUT OF THE SOUTH THRU THE
MIDDLE OF THE WEEK. SO INCREASED MORNING STRATUS...AND A RETURN OF
ISOLD TO SCATTERED AFTN/EVE SHRA/TSRA CAN BE EXPECTED BY TUESDAY-
WEDNESDAY.

CONFIDENCE TABLE...

            11-17Z        17-23Z        23-05Z        05-06Z
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...RWH
NEAR TERM...ARK
SHORT TERM...RWH
LONG TERM...RWH
AVIATION...ARK



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