Area Forecast Discussion
Issued by NWS Greer, SC

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FXUS62 KGSP 032350
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
650 PM EST WED FEB 3 2016

.SYNOPSIS...
A COLD FRONT WILL GRADUALLY MOVE EAST OF THE AREA TONIGHT. IN THE
FRONTS WAKE...DRY HIGH PRESSURE WILL SPREAD BACK OVER THE REGION AND
PERSIST INTO THE WEEKEND. A MOIST UPPER LEVEL DISTURBANCE WILL
APPROACH THE CAROLINAS EARLY NEXT WEEK.

&&

.NEAR TERM /THROUGH THURSDAY/...
AS OF 640 PM EST...THE FULL LATITUDE TROUGH OVER THE CENTRAL CONUS
CONTINUES TO MAINTAIN VERY DEEP SW FLOW OVER THE SOUTHEASTERN U.S.
THIS EVENING. THE PASSING SURFACE COLD FRONT IS GETTING INCREASINGLY
HUNG UP IN THE SOUTHWESTERLY FLOW AND THE EASTWARD PROGRESS OF THE
BOUNDARY HAS GREATLY SLOWED. WITH WEAK WAVE DEVELOPMENT HAPPENING
ALONG THE FRONTAL ZONE OVER SOUTH CENTRAL GA...ADDITIONAL WAVES OF
LIGHT TO MODERATE RAINFALL MAY BRUSH THE EASTERN FRINGE OF OUR
FORECAST AREA OVERNIGHT...AND POPS WILL BE EXTENDED ACCORDINGLY.
INSTABILITY WILL BE MARGINAL...SO HEAVY RATES ARE NOT EXPECTED...BUT
AN ADDITIONAL HALF TO THREE QUARTERS OF AN INCH OF RAIN COULD IMPACT
LOCATIONS SUCH AS UNION COUNTY IN NC IN THE PIEDMONT. THIS SHOULD
NOT WARRANT ANY ADDITIONAL FLOOD WATCHES FOR THE OVERNIGHT
HOURS...BUT PRECIP RATES WILL NEED TO BE WATCHED CLOSELY. DRYING AND
A SLOW ABATEMENT OF ANY LINGERING FLOODING IS EXPECTED. TEMP COOLING
TRENDS HAVE ALSO BEEN SLOWED DOWN IN THE FORECAST OVERNIGHT...AS HAS
THE DRYING AND LIFTING OF LOW CLOUDS AND FOG.

THE OTHER CONCERN THAT THIS SLOWER DEPARTURE CREATES IS THAT
LINGERING DEEPER MOISTURE EAST OF THE AREA THROUGH THURSDAY COULD
WELL SPILL WESTWARD FROM THE COASTAL PLAIN WITH A PASSING SURFACE
LOW THURSDAY AFTERNOON. THERE IS A SMALL CONCERN THAT THE  INTRUSION
OF COOLER AIR FROM THE WEST COULD CATCH UP WITH THIS MOISTURE TO
ALLOW MIXED PTYPES TO FORM. THERE IS STILL NOT EXPECTED TO BE
SUFFICIENT OVERLAPS OF THE COOLER THICKNESSES AND MOISTURE THROUGH
LATE THU...BUT IT BEARS WATCHING.

&&

.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...
AT 230 PM WEDNESDAY...ON THURSDAY NIGHT AN UPPER TROUGH WILL
PROGRESS ACROSS THE SOUTHERN APPALACHIANS...FOLLOWED BY AN UPPER
RIDGE ON FRIDAY AND FRIDAY NIGHT. AND UPPER TROUGH WILL APPROACH
FROM THE WEST ON SATURDAY.

AT THE SURFACE...ON THURSDAY NIGHT A COLD FRONT WILL DEPART TO THE
EAST...BUT A TIGHT PRESSURE GRADIENT WILL LINGER INTO FRIDAY. DRY
HIGH PRESSURE CROSSES THE AREA ON FRIDAY NIGHT AND SATURDAY.

&&

.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
AT 230 PM WEDNESDAY...ON SATURDAY NIGHT A SURFACE LOW CROSSING FL
AND MOVING UP THE GULF STREAM WILL SPREAD MOISTURE INLAND OVER GA
AND THE CAROLINAS...BUT THIS MOISTURE IS EXPECTED TO REMAIN EAST OF
OUR AREA. A COLD FRONT WILL ARRIVE LATE SUNDAY NIGHT...SPREADING
SNOW ACROSS THE SOUTHERN APPALACHIANS. THERE ARE INDICATIONS THAT
THE STRENGTH OF THE SYSTEM MAY SPREAD SNOW SHOWERS EAST OF THE BLUE
RIDGE AND ACROSS THE FOOTHILLS AND PIEDMONT. THESE SNOW SHOWERS WOULD
CHANGE TO RAIN SHOWERS DURING THE DAY AT ALL BUT THE HIGHEST
ELEVATIONS.

BY MONDAY EVENING THE UPPER SYSTEM RESPONSIBLE FOR THE SNOW AND RAIN
SHOWERS SHOULD MOVE OFF THE COAST...RELEGATING PRECIPITATION MAINLY
TO THE NC MOUNTAINS BORDERING TN. MOUNTAIN PRECIPITATION SHOULD
CHANGE BACK TO SNOW SHOWERS AS COLDER AIR ARRIVES...AND MAY SURVIVE
INTO MID WEEK AS SEVERAL ROUNDS OF UPPER LEVEL ENERGY ROUND A SECOND
UPPER LOW.

&&

.AVIATION /00Z THURSDAY THROUGH MONDAY/...
AT KCLT...THE MUCH SLOWER EASTWARD PROGRESSION OF THE PASSING COLD
FRONT WILL CREATE A CORRESPONDINGLY SLOWER IMPROVEMENT TREND FOR IFR
AND MVFR CIGS THROUGH THURSDAY MORNING. WILL NOW FEATURE IFR FOR
MUCH OF THE NIGHT...WITH MVFR LIKELY LINGERING WELL INTO THU MORNING
AND VFR MORE LIKELY BY THU AFTERNOON. ANY ADDITIONAL RAINFALL SHOULD
BE LIGHT. WILL KEEP VISIBILITY MAINLY MVFR GIVEN LIGHT SW MIXING
EARLY AND NW FLOW LATE...BUT IFR VSBY IN FOG WILL BE POSSIBLE AT
TIMES AS WELL.

ELSEWHERE...EXPECT LINGERING MVFR CIGS AT MOST FOOTHILL LOCATIONS
THROUGH THE EVENING HOURS...WITH IFR POSSIBLE AT TIMES. MOST OF THE
LIGHT RAINFALL SHOULD PUSH QUICKLY EAST OF THE TERMINAL
LOCATIONS...WITH JUST A FEW SPRINKLES NEARBY THROUGH 04Z. VFR WILL
GRADUALLY DEVELOP FROM THE WEST WITH DRYING OVERNIGHT...BUT A FEW
VSBY RESTRICTIONS IN FOG CAN BE EXPECTED...WITH IFR FOG POSSIBLE AT
KHKY. KAVL WILL BE VFR EARLY...BUT NW FLOW MOISTURE COULD PUSH MVFR
CIGS BACK OVER THE AIRFIELD IN THE FRENCH BROAD VALLEY. EXPECT NW
FLOW GUSTS TO DEVELOP AT KAVL OVERNIGHT AS WELL AND LINGER THROUGH
THURSDAY. SW FLOW AT THE FOOTHILL TERMINALS WILL TURN NW OVERNIGHT
AND N TO NE THROUGH THURSDAY AS HIGH PRESSURE APPROACHES FROM THE
WEST.

OUTLOOK...IN THE WAKE OF THE FRONT...LARGE HIGH PRESSURE WILL BUILD
ACROSS THE REGION THROUGH THE WEEKEND...PROVIDING UNRESTRICTED
CONDITIONS.

CONFIDENCE TABLE...

            00-06Z        06-12Z        12-18Z        18-00Z
KCLT       MED   79%     HIGH  89%     HIGH  90%     HIGH  81%
KGSP       HIGH  91%     HIGH  98%     HIGH 100%     HIGH  94%
KAVL       HIGH  97%     MED   76%     HIGH  94%     HIGH 100%
KHKY       MED   79%     HIGH  87%     HIGH  97%     HIGH 100%
KGMU       HIGH  83%     HIGH  93%     HIGH 100%     HIGH 100%
KAND       HIGH  93%     MED   77%     HIGH  94%     HIGH  94%

THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULE TAF ISSUANCE FLIGHT RULE CATEGORY.  COMPLET HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK:

WWW.WEATHER.GOV/GSP/AVIATION

&&

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

&&

$$
SYNOPSIS...JPT
NEAR TERM...HG
SHORT TERM...JAT
LONG TERM...JAT
AVIATION...HG


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