Area Forecast Discussion
Issued by NWS Greer, SC

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000
FXUS62 KGSP 010545
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
145 AM EDT MON SEP 1 2014

.SYNOPSIS...
A BERMUDA HIGH WILL REMAIN IN PLACE THROUGH EARLY IN THE
WEEK... RESULTING IN TYPICAL SUMMERTIME HEAT AND ISOLATED TO
SCATTERED AFTERNOON THUNDERSTORMS EACH DAY.

&&

.NEAR TERM /THROUGH TODAY/...
AS OF 145 AM...SHRA DISSIPATING ACROSS THE SPINE OF THE APPALACHIANS
SO HAVE TRENDED POP DOWNWARD TO NON-MENTIONABLE BEFORE DAYBREAK.
CIRRUS MUCH THICKER THAN FCST...SO HAVE UPPED AMOUNTS EARLY...THEN
ALLOW IT TO SCATTER OUT.

AS OF 1025 PM EDT...THE LAST IN A SERIES OF WEAK MID LEVEL
SHORTWAVES WILL LIFT NE ALONG THE SPINE OF THE SRN APPALACHIANS
OVERNIGHT. WITH THE REST OF THE AREA STABILIZING...ANY ISOLD
OVERNIGHT POPS WILL BE CONFINED TO THE WRN MTNS NEAR THE TN BORDER.
FOG AND LOW CLOUDS WILL BE AN ISSUE OVERNIGHT MAINLY IN THE MOUNTAIN
VALLEYS WHERE CROSSOVER TEMPS WILL BE REACHED AND ALSO ALONG AND N
OF INTERSTATE 40 WHERE HEAVIER RAIN FELL LATE TODAY. MIN TEMPS WILL
RUN 5 TO 9 DEGREES ABOVE CLIMO ACROSS THE REGION.

BERMUDA HIGH WILL REMAIN STRONG THROUGH MONDAY. A BIT MORE MIXING IS
EXPECTED TOMORROW AFTN...WITH RH VALUES A LITTLE MORE TOLERABLE.
EXPECT HIGHS TO REACH ABOUT TWO CATEGORIES ABOVE NORMAL IN THE WARM
AIRMASS. ISOLD TO SCT DIURNAL CONVECTION WILL FAVOR THE HIGH TERRAIN
MON AFTN IN WEAK TERRAIN FORCED TRIGGERING.

&&

.SHORT TERM /TONIGHT THROUGH WEDNESDAY/...
AS OF 215 PM SATURDAY...TYPICAL LATE SUMMER WEATHER IS EXPECTED
THROUGH THE SHORT TERM...AS SUBTROPICAL/BERMUDA HIGH PRESSURE
GENERALLY MAINTAINS ITS HOLD ACROSS THE SOUTHEAST. A SHORT WAVE
TROUGH PASSING NORTH OF OUR REGION LATE TUE. ASSOCIATED COLD FRONT
WILL APPROACH THE SOUTHERN APPALACHIANS FROM THE TENN VALLEY TUE
EVENING... POSSIBLY ENHANCING CONVECTIVE CHANCES ACROSS THE NC MTNS
DURING THIS TIME. HOWEVER...WITH THE PRIMARY SYNOPTIC SCALE FORCING
PASSING BY TO OUR NORTH...WEAK SHEAR...AND WEAKENING INSTABILITY
ASSOCIATED WITH THE NOCTURNAL COOLING CYCLE...IT/S NOT CLEAR HOW
LONG INTO TUE NIGHT CONVECTION WILL CONTINUE BEFORE DISSIPATING.
CHANCE POPS HAVE GENERALLY BEE LIMITED TO THE EVENING HOURS.

THE FRONT IS EXPECTED TO INTRODUCE A SLIGHTLY COOLER/SLIGHT DRIER
AIR MASS TO THE AREA...WITH TEMPS EXPECTED TO TOP OUT CLOSER TO
CLIMO FOR WED AFTERNOON. IT DOES NOT APPEAR THAT ANY DRYING WILL BE
SUBSTANTIAL ENOUGH TO PRECLUDE AFTERNOON DESTABILIZATION AND DIURNAL
CONVECTIVE DEVELOPMENT. NEAR-CLIMO POPS (LOW CHANCE MTNS/SLIGHT
CHANCE EAST) WILL BE ADVERTISED WED AFTERNOON.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
AS OF 230 PM EDT SUNDAY...LATEST GLOBAL MODELS HAVE TRENDED WEAKER
UPPER RIDGING ACROSS THE SOUTHERN CONUS...LEADING TO INCREASING
CHANCES FOR CONVECTION THROUGHOUT THE MEDIUM RANGE PERIOD. WED NIGHT
THRU FRI...MODELS STILL DEPICT UPPER RIDGING AMPLIFYING ACROSS THE
REGION THRU THU...THEN WEAKENS BY FRI IN RESPONSE TO A NORTHERN
UPPER TROUGH TRAVERSING THE UPPER MIDWEST. A FRONTAL BOUNDARY JUST
TO OUR SOUTH WILL BE WASHED OUT BY THURSDAY AS A BERMUDA HIGH
RE-BUILDS ACROSS THE SOUTHEAST AND REMAIN IN PLACE THRU FRI. DESPITE
THE UPPER RIDGING ALOFT...ATLANTIC MOISTURE INFLUX AND MODERATE
DIURNAL BUOYANCY (1500-2500J/KG SBCAPE) WILL BE SUPPORTIVE OF
SCATTERED CONVECTION. HENCE...HAVE UPDATED POPS TO INCREASE TO
AROUND 40-50 RANGE. SAT AND SUNDAY...THE UPPER RIDGE FLATTENS OUT
OVER THE SOUTHEAST AS THE UPPER TROUGH MOVES ACROSS THE GREAT LAKES
REGION SAT AND INTO THE OHIO VALLEY BY SUN. THIS WILL ALLOW COOLER
SURFACE HIGH TO SLIDE SOUTH...PUSHING A BACK DOOR COLD FRONT THROUGH
THE FORECAST AREA BY SAT NIGHT/EARLY SUN. WITH GOOD LLVL
CONVERGENCE...UPPER DPVA...MOIST PROFILE AND MODERATE
INSTABILITY...WE SHOULD SEE RATHER ACTIVE WEATHER PATTERN WITH HEAVY
RAINFALL BEING THE PRIMARY THREAT ATT. TEMPS WILL BE AROUND 2-3
DEGREES ABOVE NORMAL THURSDAY AND NEAR NORMAL FRI INTO SUN.

&&

.AVIATION /06Z MONDAY THROUGH FRIDAY/...
AT KCLT...BKN CIRRUS WILL SLOWLY MOVE OUT OF THE AREA OVERNIGHT
ALLOWING MVFR FOG TO DEVELOP NEAR DAYBREAK. THE FOG SHUD DISSIPATE
RELATIVELY QUICKLY DURING THE MORNING. EXPECT HIGH BASED CU TO
DEVELOP THRU THE DAY AND BECOME BKN BY LATE AFTERNOON...THEN SCATTER
OUT DURING THE EVENING. LIGHT SW WIND THIS MORNING BECOMES SW AFTER
DAYBREAK...THEN WSW FOR THE AFTERNOON. LIGHT SLY WIND EXPECTED
DURING THE EVENING.

ELSEWHERE...OUTSIDE OF THE MTNS WILL SEE SIMILAR CONDITIONS AS KCLT.
MVFR FOG AROUND DAYBREAK AND SWLY WINDS THRU THE PERIOD. CU MAY TAKE
LONGER TO BECOME BKN OVER THE SC STIES...AND MAY REMAIN SCT. KAVL
HAS THE BEST CHC OF SEEING ANY IFR OVERNIGHT...SO HAVE KEPT THAT
THERE. AFTERNOON CONVECTION MOST LIKELY AT KAVL...BUT CHC STILL TO
LOW TO INCLUDE IN THE TAF ATTM. WIND AT KAVL WILL BE CALM
OVERNIGHT...NWLY AFTER DAYBREAK...SLY FOR THE AFTERNOON THEN
BECOMING CALM DURING THE EVENING.

OUTLOOK...GENERALLY VFR CONDITIONS ARE EXPECTED THROUGH MOST OF THE
WEEK...BUT RESTRICTIONS ARE POSSIBLE EARLY EACH MORNING DUE TO LOW
CLOUDS AND FOG...PRIMARILY IN THE MOUNTAIN VALLEYS. DIURNALLY DRIVEN
SHRA/TSRA ARE EXPECTED EACH AFTERNOON WITH THE MOST COVERAGE OVER
THE MOUNTAINS.

CONFIDENCE TABLE...

            05-11Z        11-17Z        17-23Z        23-05Z
KCLT       HIGH 100%     HIGH  97%     HIGH 100%     HIGH 100%
KGSP       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KAVL       HIGH  84%     MED   75%     HIGH 100%     HIGH 100%
KHKY       HIGH  94%     HIGH 100%     HIGH 100%     HIGH 100%
KGMU       HIGH 100%     HIGH  97%     HIGH 100%     HIGH 100%
KAND       HIGH  91%     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...JOH
NEAR TERM...HG/RWH
SHORT TERM...JDL
LONG TERM...JOH
AVIATION...RWH





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