Area Forecast Discussion
Issued by NWS Greer, SC

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000
FXUS62 KGSP 041051
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
651 AM EDT TUE AUG 4 2015

.SYNOPSIS...
DRY HIGH PRESSURE WILL WEAKEN TODAY AS A WEAK COLD FRONT DROPS SOUTH
TOWARD OUR REGION. LOW LEVEL MOISTURE WILL GRADUALLY RETURN THROUGH
THE WORK WEEK AS THIS COLD FRONT APPROACHES FROM THE AREA FROM THE
NORTHWEST.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 645 AM...CONVECTION TO THE NW HAS DISSIPATED AND SHOULD NOT
REDEVELOP THIS MORNING. THERE WILL BE QUITE A BIT OF CONVECTIVE
DEBRIS ACROSS THE NRN TIER THIS MORNING BEFORE CU DEVELOPS THRU THE
DAY. OTHERWISE...GOING FCST LOOKS ON TRACK WITH UPDATES MAINLY FOR
CURRENT CONDITIONS.

AS OF 255 AM...CONVECTION ASSOCIATED WITH AN MCS TO OUR NW IS
SHOWING DIMINISHING COVERAGE. HOWEVER...THOSE CELLS ARE MAINTAINING
THEIR STRENGTH AS THEY MOVE SLOWLY ESE. IF THE ACTIVITY HOLDS
TOGETHER...THEN IT COULD BRUSH THE NRN MTNS NEAR DAYBREAK. DO NOT
EXPECT IT TO MOVE EAST OF THE MTNS THIS MORNING.

THE BROAD TROF EXTENDING FROM ERN CANADA THROUGH THE SE UNITED
STATES BEGINS TO LIFT TODAY WITH HEIGHTS RISING AND FLOW BECOMING
MORE WLY. AT THE SFC...A LOW PRESSURE CENTER WILL MOVE NE ALONG A
FRONTAL BOUNDARY NEAR THE SERN COAST. MOISTURE AND FORCING
ASSOCIATED WITH THIS LOW WILL REMAIN WELL TO OUR EAST. A COLD FRONT
DROPPING SOUTH TOWARD THE AREA WILL HAVE A GREATER EFFECT ON OUR
SENSIBLE WX. PROFILES ARE STILL ON THE DRY SIDE... BUT 850 TO 500 MB
LAPSE RATES SHOULD STEEPEN TO 6.5 DEG C OR BETTER. THE LOW LEVEL
CONVERGENCE ASSOCIATED WITH THE FRONT COULD BE ENUF TO ACT ON THE
DEVELOPING INSTABILITY TO CREATE ISOLATED TO SCT DIURNAL CONVECTION
ACROSS THE MTNS. THE WLY FLOW COULD DRIVE ANY CONVECTION EASTWARD
OVER THE NC PIEDMONT THROUGH LATE DAY. HAVE GONE ISOLATED THERE...
WITH A CONTINUED DRY FCST ACROSS THE UPSTATE AND NE GA. CONVECTION
SHOULD DIMINISH DURING THE EVENING...BUT MORE MCS ACTIVITY COULD
DROP TOWARD THE MTNS AGAIN OVERNIGHT. HOWEVER...CHC TOO LOW TO
INCLUDE ATTM. WILL BE ANOTHER HOT DAY WITH HIGHS IN THE LOW TO MID
90S OUTSIDE OF THE MTNS...AND AROUND 90 IN THE WARMER MTN VALLEYS.
DEW POINTS SHOULD MIX OUT ENUF TO KEEP THE HIGHEST HEAT INDEX VALUES
NEAR 100. LOWS TONIGHT WILL BE UP TO 5 DEGREES ABOVE NORMAL.

&&

.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AT 230 AM EDT TUESDAY...ON WEDNESDAY MORNING AN UPPER TROUGH WILL BE
OVER THE ROCKIES...AND AND UPPER TROUGH EAST OF THE MS RIVER. THE
PATTERN LARGELY DEAMPLIFIES BY THURSDAY. A WELL DEFINED SHORTWAVE IS
EXPECTED TO APPROACH THE SOUTHERN APPALACHIANS ON THURSDAY...
CROSSING THE AREA ON THURSDAY NIGHT.

AT THE SURFACE...A COLD FRONT WILL STALL OVER OUR AREA ON
WEDNESDAY...WHILE MOISTURE FROM THE GULF OF MEXICO MOVES NORTH
TOWARD THE BOUNDARY. THE MODELS EVEN SHOW A WEAK LOW SPINNING UP
ALONG THE FRONT NEAR THE EASTERN PORTION OF OUR AREA. THE MODELS
DISAGREE ON HOW MUCH INSTABILITY WILL BE PRESENT NEAR THE
FRONT...BUT AGREE ON INCREASING MOISTURE. ALTHOUGH PRECIPITATION
COVERAGE IS EXPECTED TO INCREASE...LOW LEVEL FLOW WILL GENERALLY BE
SOUTHWESTERLY...LIMITING UPSLOPE FLOW INTO HIGH TERRAIN.
TEMPERATURES WILL RUN ABOVE NORMAL.

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
AT 230 AM EDT TUESDAY...ON FRIDAY MORNING A LOW AMPLITUDE UPPER
RIDGE WILL BE OVER THE PLAINS...AND A TROUGH WILL BE OVER THE EAST.
THIS PATTERN SLOWLY PROGRESSES SUCH THAT THE TROUGH MOVES OFF THE
EAST COAST ON SATURDAY. THE UPPER RIDGE AMPLIFIES OVER THE CENTER OF
THE NATION ON SUNDAY...AND BUILDS EAST ACROSS THE GULF STATES. THE
UPPER TROUGH PERSIST JUST OFF THE EAST COAST THROUGH MONDAY.

AT THE SURFACE...A NEARLY STATIONARY FRONT WILL BE IN OUR VICINITY
ON FRIDAY...AND MOVES SLOWLY SOUTH INTO SATURDAY. THIS SYSTEM WILL
SERVE AS A FOCUSING MECHANISM FOR PRECIPITATION AS MOISTURE SPREADS
EAST ALONG IT...AND MODEL SOUNDING SHOW ENOUGH INSTABILITY TO SUPPORT
CONVECTION. THE BOUNDARY IS EXPECTED TO STALL WELL TO OUR SOUTH BY
SUNDAY...WHILE ANOTHER FRONT APPROACHES FROM THE NW. THE SECOND FRONT
IS EXPECTED TO STALL NEAR THE COAST ON MONDAY...WITH OSTENSIBLY DRIER
AIR ARRIVING IN ITS WAKE. TEMPERATURES WILL RUN NEAR NORMAL.

&&

.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
AT KCLT...VFR MOST LIKELY WILL PREVAIL THRU THE PERIOD. REGIONAL OBS
AND SAT PIX SHOW SOME LOW STRATUS TO THE EAST...BUT THEY SHOULD
REMAIN EAST OF THE AIRFIELD...ALTHOUGH THEY MAY GET CLOSE ENUF TO BE
SEEN. OTHERWISE...EXPECT CU TO DEVELOP THRU THE DAY WITH BKN CIRRUS.
THERE IS A SMALL CHC OF CONVECTION THIS AFTERNOON...BUT TOO LOW TO
INCLUDE IN THE TAF ATTM. NWLY GUSTS FROM UPSTREAM OUTFLOW BOUNDARIES
ARE MORE LIKELY THAN ACTUAL SHRA/TSRA. IGHT SE WIND BECOMES S THEN
SSW THRU THE DAY...THEN CALM OVERNIGHT. DO NOT EXPECT ANY
RESTRICTIONS OVERNIGHT. THAT SAID...THERE MAY BE MORE LOW STRATUS TO
THE EAST AGAIN.

ELSEWHERE...CANNOT RULE OUT ANOTHER BRIEF CIG AT KAND EARLY THIS
MORNING...BUT EXPECT VFR THRU THE PERIOD ALL LOCATIONS. KAVL/KHKY
HAVE THE BEST CHC OF SEEING ANY CONVECTION TODAY...BUT CHC TOO LOW
TO INCLUDE IN THE TAF ATTM. OTHERWISE...EXPECT DEVELOPING CU THRU
THE DAY WITH BKN CIRRUS. LIGHT S TO SW WINDS EXPECTED THRU THE DAY
WITH NEAR CALM WINDS OVERNIGHT. KAVL THE EXCEPTION WITH NNW WIND.
LITTLE TO NO CHC OF RESTRICTIONS OVERNIGHT.

OUTLOOK...GRADUALLY INCREASING PRECIPITATION/RESTRICTION CHANCES ARE
EXPECTED THROUGH THE WEEK AS MOISTURE RETURNS AND A FRONT STALLS IN
OUR VICINITY...WITH A DISTURBANCE THEN MOVING ALONG IT.

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  94%     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...JAT
NEAR TERM...RWH
SHORT TERM...JAT
LONG TERM...JAT
AVIATION...RWH



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