Area Forecast Discussion
Issued by NWS Greer, SC

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000
FXUS62 KGSP 030606
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
206 AM EDT THU SEP 3 2015

.SYNOPSIS...
A WEAK PRESSURE PATTERN WILL LINGER ATOP THE REGION FOR THE REST OF
THE WORKWEEK. LATE SUMMER WARMTH AND DAILY THUNDERSTORM CHANCES WILL
BE THE MAIN FEATURES OF INTEREST. A BACK DOOR COLD FRONT IS EXPECTED
TO PUSH ACROSS THE REGION ON FRIDAY FOLLOWED BY A COOL AND MOIST
AREA OF HIGH PRESSURE THIS WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 2 AM EDT...WATER VAPOR IMAGERY SHOWS A SHORTWAVE MOVING EAST
THROUGH CENTRAL TN EARLY THIS MORNING. HIGH LEVEL CLOUDINESS AHEAD
OF THIS WAVE SHOULD GENERALLY QUASH ANY MORNING FOG AND LOW CLOUD
POTENTIAL. THE UPPER FEATURE MAY BRING SLIGHTLY ENHANCED UPWARD
VERTICAL VELOCITIES THROUGH THE SRN TIER OF THE FORECAST AREA
TODAY...WITH THE BEST DEEP LAYER Q VECTOR CONVERGENCE CROSSING THE
REGION DURING THE MORNING HOURS. THIS TIMING WILL NOT FAVOR
CONVECTIVE DEVELOPMENT...BUT 850 TO 500 MB LAPSE RATES WILL STEEPEN
THROUGH THE DAY...AND SRN TIER INSTABILITY MAY LINGER THROUGH THE
MORNING HOURS WHERE HIGHER SFC DEWPOINTS HAVE POOLED. IN ADDITION TO
THIS SRN TIER FORCING...ANOTHER ROUND OF ISOLD TO SCT RIDGE TOP
SHOWER/TSRA DEVELOPMENT IS EXPECTED WITH PEAK HEATING. ANY ACTIVITY
THAT DEVELOPS IN THE MARGINALLY UNSTABLE PROFILES MAY DRIFT OFF THE
BLUE RIDGE INTO THE ADJACENT FOOTHILLS IN NW FLOW ALOFT LATER THIS
AFTN OR EARLY EVENING...BUT DEWPOINT MIXING SHOULD LIMIT POTENTIAL
FARTHER OUT INTO THE PIEDMONT. DESPITE MID AND HIGH CLOUDS
INHIBITING HEATING SOMEWHAT TODAY...PLENTY OF LOWER 90S ARE STILL
EXPECTED EAST OF THE MTNS THIS AFTERNOON.

ANY LINGERING SHOWER ACTIVITY SHOULD GENERALLY WANE TONIGHT WITH THE
LOSS OF INSTABILITY AND THE PERSISTENT N TO NE FLOW FROM SFC HIGH
PRESSURE TO THE N. ADDITIONAL 500 MB SHORTWAVE ENERGY WILL DROP SE
TOWARD THE SRN APPALACHIANS OVERNIGHT...BUT LIMITED MOISTURE. WILL
CONFINE ANY OVERNIGHT SLIGHT CHANCES OF PRECIPITATION TO THE NRN
MOUNTAINS.

&&

.SHORT TERM /FRIDAY THROUGH SATURDAY/...
AS OF 215 PM WEDNESDAY...AN UPPER LEVEL HIGH WILL BEGIN TO
STRENGTHEN OVER THE NORTHEAST STATES...WHILE A RELATIVE WEAKNESS
WILL LINGER AROUND ITS WESTERN AND SOUTHERN PERIPHERY...EXTENDING
FROM THE OHIO VALLEY TO THE SOUTHEAST STATES. THIS WILL PLACE THE
CWFA WITHIN VERY WEAK MID AND UPPER LEVEL FLOW THRU THE SHORT TERM.
AT THE SFC...HIGH PRES WILL BUILD OVER NEW ENGLAND...RIDGING
SOUTHWESTWARD THRU THE CAROLINAS. A WEAK BACK DOOR COLD FRONT WILL
PUSH THRU THURSDAY NIGHT...WITH GRADUALLY INCREASING NORTHEASTERLY
TO EASTERLY LLVL FLOW FRIDAY THRU SATURDAY. GUIDANCE IS IN PRETTY
GOOD AGREEMENT ON THE FLOW TRANSPORTING INCREASING LOW-MID LVL
MOISTURE. THIS COMBINED WITH FALLING HEIGHTS ALOFT SHUD RESULT IN AN
INCREASE IN INSTBY FOR FRIDAY AND SATURDAY. THE EASTERLY FLOW WILL
ALSO ENHANCE UPSLOPE FORCING ALONG THE BLUE RIDGE FOR LIFT. SO I
WILL FCST A SHOTGUN CHC POP ON FRIDAY...WITH SLIGHTLY HIGHER VALUES
IN THE HIGH TERRAIN...AND SOLID CHC TO LOW-LIKELY POP FOR SATURDAY.
THIS IS NOT MUCH CHANGE FROM PREVIOUS FCST. FRIDAY STILL LOOKS TO
SEE ABOVE NORMAL TEMPS...AS THICKNESSES DON/T FALL MUCH UNTIL
SATURDAY. MORE CLOUD COVER AND PRECIP ON SATURDAY WILL RESULT IN
TEMPS ABOUT A CATEGORY BELOW NORMAL.

&&

.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
AS OF 100 PM WEDNESDAY...THE LATEST MEDIUM RANGE GUIDANCE SUPPORTS
THE GOING THINKING OF SFC RIDGING CONTINUING TO NOSE SSWD INTO THE
CWFA THROUGH SUNDAY. THE PROGGED PRESSURE GRADIENT LOOKS SIMILAR TO
SATURDAY...BUT THINKING CLOUDS WILL BE A TAD THINNER WITH MAXIMUM
TEMPERATURES A HAIR WARMER. WITH SFC PRESSURES FCST TO RISE ON LABOR
DAY MONDAY...PROGRESSIVELY LESS CLOUD COVER AND MAX TEMPERATURES
CLIMBING TOWARD CLIMO IS EXPECTED. THE INHERITED CLIMO RANGE...
DIURNALLY ENHANCED DEEP CONVECTIVE CHANCES WILL REMAIN AS IS.
BACK TO MORE TYPICAL LATE SUMMER CONDITIONS ON TUESDAY FEATURING
TEMPERATURES AND POP NEAR CLIMO WITH AN INCREASE IN RETURN FLOW
PROMPTING GREATER TSTM CHANCES FOR THE NEW DAY 7.

&&

.AVIATION /06Z THURSDAY THROUGH MONDAY/...
AT KCLT AND ELSEWHERE...MID AND HIGH LEVEL MOISTURE AHEAD OF AN
APPROACHING SHORTWAVE WILL PROVIDE ALTOCUMULUS AND CIRRUS CIGS
THROUGH MUCH OF THE PERIOD...BUT WITH LOWER CONVECTIVE CUMULUS SLOW
TO BUILD WITH DEWPOINT MIXING EXPECTED ONCE AGAIN TODAY. THE BEST
PRECIPITATION CHANCES DURING THE TAF PERIOD WILL BE WITH AN UPPER
LEVEL SHORTWAVE CROSS THE SRN TIER OF THE TERMINAL FORECAST AREA
TODAY...AND WITH SCATTERED RIDGE TOP DEVELOPMENT OVER THE HIGHER
TERRAIN. CONFIDENCE IS TOO LOW TO FEATURE ANY SHRA/TSRA AT THE
TERMINALS YET. EXPECT MAINLY LIGHT NW TO NE WINDS THROUGHOUT THE
PERIOD...POSSIBLY TOGGLING WEST NEAR KAND THIS AFTN AND EVENING.

OUTLOOK...A PATTERN OF DIURNAL ISOLATED/SCT SHOWERS AND
THUNDERSTORMS IS EXPECTED TO CONTINUE THROUGH FRIDAY. BY THE
WEEKEND...A MOIST EASTERLY FLOW SHOULD DEVELOP...BRINGING BETTER
CHANCES FOR SHOWERS AND RESTRICTIONS. LOW CLOUDS AND FOG WILL BE
POSSIBLE EACH NIGHT IN THE MOUNTAIN VALLEYS.

CONFIDENCE TABLE...

            06-12Z        12-18Z        18-24Z        00-06Z
KCLT       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KGSP       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KAVL       HIGH 100%     HIGH  97%     HIGH 100%     HIGH 100%
KHKY       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KGMU       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KAND       HIGH  97%     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

&&

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

&&

$$
SYNOPSIS...CSH
NEAR TERM...HG
SHORT TERM...ARK
LONG TERM...CSH
AVIATION...HG



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