Area Forecast Discussion
Issued by NWS Greer, SC

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000
FXUS62 KGSP 271841
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
241 PM EDT MON OCT 27 2014

.SYNOPSIS...
HIGH PRESSURE WILL GIVE WAY TO A PROGRESSIVELY WARMER SOUTHWEST FLOW
BEFORE A COLD FRONT CROSSES THE REGION ON WEDNESDAY. A LARGE AREA OF
HIGH PRESSURE WILL BUILD IN FROM THE NORTHWEST LATE IN THE WEEK AND
PERSIST THROUGH THE WEEKEND...RESULTING IN BELOW NORMAL TEMPERATURES.

&&

.NEAR TERM /THROUGH TUESDAY/...
AS OF 225 PM EDT...DEEP RIDGING WILL PERSIST OVER THE SOUTHEAST
COASTAL REGION THRU TONIGHT ALLOWING LIGHT SOUTHERLY FLOW TO
CONTINUE. THE MID TO UPPER LEVELS WILL BE QUITE DRY...AND VIRTUALLY
CLEAR SKIES WILL BE SEEN. LLVL RH HOWEVER WILL REBOUND A BIT ON THE
SOUTHERLY FLOW...WHICH BEGINS TO VEER MORE SWLY INTO TOMORROW
MORNING IMPLYING SOME RETURN OFF THE GULF. AS ONE MIGHT
EXPECT...SOME OF THE GUIDANCE MEMBERS FROM BOTH THE NAM AND GFS
FAMILIES DO DEVELOP SOME FOG AND/OR LOW STRATUS INTO THE SRN UPSTATE
AND NE GA. IT IS A PLAUSIBLE SOLUTION THOUGH VERTICAL PROFILES ARE
NOT AS CONDUCIVE IN OUR AREA AS IN AREAS FURTHER SOUTH. REFLECTED
THE POSSIBILITY WITH PCLDY WORDING AROUND DAYBREAK SOUTH OF I-85.
ANY STRATUS SHOULD BREAK UP BY MID MRNG AND LEAVE MOSTLY CLEAR SKIES
OVER THE PIEDMONT...WITH A FEW CLOUDS SEEN OVER THE MTNS. MIN TEMPS
TONIGHT WILL COOL INTO THE UPPER 40S MTNS AND LOWER 50S PIEDMONT
UNDER EXCELLENT RADIATIVE CONDITIONS. MAXES TUESDAY WILL BE SIMILAR
TO THOSE TODAY...AGAIN WITHIN A FEW DEGREES OF RECORDS. SEE CLIMATE
SECTION BELOW.

&&

.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/...
AS OF 215 PM MONDAY...A STRONG UPPER TROUGH IS FORECAST TO DIG
THROUGH THE GREAT LAKES TUE NIGHT INTO WED. THIS WILL DRIVE A
SURFACE COLD FRONT SOUTHEASTWARD. THE FRONT WILL REACH THE WESTERN
NC/TN BORDER COUNTIES BY ABOUT SUNRISE WED AND THEN PUSH ACORSS THE
REMAINDER OF WESTERN NC/NE GA AND UPSTATE SC BY AROUND SUNSET.

THE MODELS REMAIN IN GOOD AGREEMENT ON THE TIMING/DEPICTION OF THE
COLD FRONT FOR WEDNESDAY. WITH THE BULK OF THE UPPER ENERGY AND THE
PARENT SFC LOW REMAINING WELL NORTH OF THE REGION...THE FRONT WILL
JUST HAVE A SHORT WINDOW FOR MOISTURE ADVECTION FROM THE GULF OF
MEXICO. HENCE...A RELATIVELY NARROW BAND OF HIGH RH WILL ACCOMPANY
THE FRONT AS IT SAGS SOUTHEASTWARD THRU THE AREA DURING THE DAY ON
WEDNESDAY. EVEN SO...THE QPF RESPONSE FROM BOTH THE NAM AND GFS
INDICATE THAT ESPECIALLY THE MOUNTAINS WILL SEE NUMEROUS
SHOWERS...WITH SCATTERED SHOWERS ELSEWHERE. THE NAM IS FORECASTING
400-800 J/KG ACRS UPSTATE SC BY MID AFTN...SO A FEW THUNDERSTORMS
ARE ALSO POSSIBLE IN THAT AREA.

THE FRONT WILL MOVE AWAY FROM THE AREA WED NIGHT ALLOWING SHOWERS TO
END WED EVENING OVER THE PIEDMONT. WEAK HIGH PRESSURE WILL THEN
BUILD OVER THE REGION FROM THE NW ON THU. USED A MODEL BLEND
FOR TEMPS.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
AS OF 150 PM MONDAY...GOOD AGREEMENT IS HAD BTW THE OP MODELS WRT TO
THE LARGE SCALE PATTERN THROUGH MOST OF THE PERIOD. THE LATEST GFS
IS FASTER THAN THE ECWMF WITH THE UPPER RIDGE AXIS TRANSLATING EAST
BY SUN NIGHT...HOWEVER THIS WILL NOT IMPACT THE SENSIBLE WX FCST.

STILL EXPECT WEAKENING AND A MOISTURE LIMITED SFC FRONT TO APPROACH
THE NC MTNS FRI NIGHT WITH A TIGHTENING P/GRAD AND HEIGHT FIELD
LINGERING THROUGHOUT THE DAY SAT. THE ECMWF HAS BACKED OFF THE QPF
RESPONSE OVER THE WRN MTNS WHICH WASNT MUCH TO BEGIN WITH...WHILE
THE GFS KEEPS JUST ENOUGH LLVL MOISTURE FOR LOW END PRECIP. WILL ADD
SLIGHT CHANCE POPS OVER THE NRN MTNS FOR A FEW HRS FRI NIGHT TO
INCLUDE -SNSH WITH NO SIGFNT ACCUM. THE SFC-H85 CAA WILL BE MODERATE
AND SFC WINDS WILL BECOME RATHER GUSTY...YET LIKELY BELOW ADVISORY
LEVELS. DRY AIR WILL PERSIST OVER THE CWFA THROUGH PERIOD WITH COLDER
THAN NORMAL TEMPS. SAT NIGHT SHOULD SEE THE LOWEST MINS AS A
REINFORCING CP SFC HIGH PUSHES IN. AREAS OUTSIDE THE MTNS...MAINLY
THE NC FTHILLS AND PIEDMONT WILL POSSIBLY EXPERIENCE SUB/FREEZING
MINS. MAX TEMPS WILL STRUGGLE IN THIS AIRMASS WITH MAXES ABOUT 5
DEGREES BELOW NORMAL FRI...AND ABOUT 10 DEGREES BELOW NORMAL OVER
THE WEEKEND. A GENERAL WARMUP IS EXPECT TO BEGIN MON.

&&

.AVIATION /19Z MONDAY THROUGH SATURDAY/...
AT KCLT AND ELSEWHERE...SETTLED CONDITIONS WILL CONTINUE THRU 18Z
TUE. THE PATTERN OVER THE SOUTH ATLANTIC REGION WILL BE DOMINATED BY
A DEEP RIDGE WITH PREVAILING SOUTHERLY FLOW...SLOWLY VEERING TO MORE
SWLY EARLY TUE. VIRTUALLY CLEAR SKIES MAY BE EXPECTED THRU THE
PERIOD. HOWEVER THE EXCELLENT RADIATION AS WELL AS GRADUAL MOISTURE
RETURN ABOVE THE BOUNDARY LAYER WILL MAKE CONDITIONS FAVORABLE FOR
SOME MTN VALLEY FOG TONIGHT. THIS IS REFLECTED AT KAVL. ALSO OF
NOTE...SOME GUIDANCE DOES SHOW IFR STRATUS/FOG CREEPING NWD THRU
CENTRAL GA/SC JUST BEFORE DAYBREAK. THIS IS A RESULT OF THE
AFOREMENTIONED LLVL MOISTURE ADVECTION. THERE IS NO SUPPORT FOR
RESTRICTIONS AT ANY OF THE SITES...BUT I DID INCLUDE A SCT MENTION
AT KAND TO HIGHLIGHT THE POSSIBILITY.

OUTLOOK...MOSTLY VFR CONDITIONS WILL CONTINUE EARLY THIS WEEK
WITH A DEEP LAYER RIDGE REMAINING IN CONTROL. A COLD FRONT IS
EXPECTED TO CROSS THE REGION ON WEDNESDAY WHICH COULD BRING SOME
BRIEF RESTRICTIONS WITH SHOWERS.

&&

.CLIMATE...
RECORD HIGHS FOR TUESDAY OCT 28...
GSP  85      1991
CLT  87      1940
AVL  81      1940

&&

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

&&

$$
SYNOPSIS...SBK
NEAR TERM...WIMBERLEY
SHORT TERM...LG
LONG TERM...SBK
AVIATION...WIMBERLEY
CLIMATE...WIMBERLEY



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