Area Forecast Discussion
Issued by NWS Greer, SC

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000
FXUS62 KGSP 271743
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
1243 PM EST THU NOV 27 2014

.SYNOPSIS...
AN UPPER LEVEL DISTURBANCE WILL MOVE OFF TO THE EAST TODAY...
ALLOWING DRY HIGH PRESSURE TO RETURN FRIDAY AND LINGER INTO THE
WEEKEND. EXPECT A COLD FRONT TO SLOWLY CROSS OUR REGION FROM THE
NORTH EARLY NEXT WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 1240 PM...NUMEROUS LIGHT SNOW SHOWERS ACROSS THE NC MTNS WILL
SLOWLY DIMINISH IN COVERAGE THRU THE AFTERNOON...BUT LINGER THRU THE
EVENING. DO NOT EXPECT ANY SIGNIFICANT ADDITIONAL ACCUMULATIONS THIS
AFTERNOON OR EVENING...SO HAVE ALLOWED THE ADVISORY TO EXPIRE. THAT
SAID...ADDITIONAL VERY LIGHT ACCUMS ARE POSSIBLE IN THE HIGHER
ELEVATIONS NEAR THE TN BORDER. CLOUDS WILL LINGER ACROSS THE MTNS
INTO THE EVENING AS WELL. MORE THAN EXPECTED CLOUDS HAVE SPILLED OUT
OF THE MTNS AND ACROSS THE FOOTHILLS...PIEDMONT AND UPSTATE...SO
HAVE UPPED CLOUD COVER THERE. STILL SHUD SEE QUITE A BIT OF SUNSHINE
OVERALL. THEREFORE...HIGH TEMPS LOOK ON TRACK WITH ONLY MINOR
ADJUSTMENTS. GUSTY NWLY WINDS WILL CONTINUE THRU THE AFTERNOON
OUTSIDE OF THE MTNS AND LINGER THRU THE NITE ACROSS THE MTNS.

AS OF 945 AM...RADAR SHOWING PRECIP ACROSS THE NW PIEDMONT CONTINUES
TO MOVE EAST OUT OF THE AREA. THAT SAID...A FEW SPRINKLES COULD FALL
THRU NOON. ACROSS THE MTNS...SNOW SHOWERS CONTINUE WITH ANOTHER
ROUND OF HEAVIER SNOW SHOWERS UPSTREAM TO MOVE THRU BEFORE NOON. MAY
NEED TO EXTEND THE ADV INTO THE AFTERNOON TO COVER THIS ROUND IF IT
MOVES SLOWER OR LINGERS LONGER. OTHERWISE...EXPECT THE SNOW TO TAPER
OFF AND BECOME MORE OF A HIGHER ELEVATION AND TENNESSEE BORDER AREA
EVENT WITH NO SIGNIFICANT ACCUMULATIONS FROM LATE AFTERNOON ON. SOME
CLOUDINESS WILL SPILL OUT OF THE MTNS AND ACROSS THE NC FOOTHILLS
AND PIEDMONT THRU THE DAY WHILE OTHER CLOUDS MOVE ACROSS THE UPPER
SAVANNAH RIVER VALLEY. HIGH TEMPS LOOK ON TRACK.

AS OF 645 AM...THE LAST AREA OF UPGLIDE-INDUCED PATCHY LIGHT RAIN IS
LIFTING NORTHEAST OF THE AREA...WHILE NW FLOW SHOWERS HAVE BEGUN TO
GENERATE ACROSS THE SOUTHERN APPALACHIANS...ALTHOUGH THEY REMAIN
QUITE SCATTERED ATTM. THIS SHOULD CHANGE AS THE BOUNDARY LAYER FLOW
TAKES ON A MORE BARRIER-PERPENDICULAR FLOW. POPS WILL THUS RAMP BACK
UP BY MID-MORNING. OTHERWISE...A SMALL AREA OF DENSE FOG DEVELOPED
EARLIER ACROSS THE NORTHWEST PIEDMONT AND NORTHERN FOOTHILLS. THIS
WAS HANDLED WITH AN EARLIER SPS...AND THE FOG SHOULD ERODE QUICKLY
AS DRIER AIR FILTERS IN BEHIND SURFACE FRONT.

UPGLIDE-FORCED/PATCHY LIGHT PRECIP EVENT WILL WIND DOWN OVER THE
NEXT COUPLE OF HOURS...AS WATER VAPOR IMAGERY INDICATES UPPER LEVEL
SPEED MAX IS ALREADY PUNCHING INTO THE WESTERN CAROLINAS. WEAK
SURFACE BOUNDARY WILL PUSH ACROSS THE AREA THROUGH THE MORNING...
TURNING WINDS TOWARD THE NW...SCOURING MUCH OF THE CLOUD COVER EAST
OF THE MTNS (WITH THE EXCEPTION OF THE I-40 CORRIDOR/WESTERN NC
PIEDMONT...AND ALLOWING PRECIP EVENT TO TRANSITION TO MORE OF A
TYPICAL NW FLOW SNOW EVENT FOR THE FAR WESTERN NC MTNS. IT APPEARS
THERE WILL BE A LULL OF AT LEAST A COUPLE OF HOURS IN MTN
PRECIP...BEFORE THE NW FLOW BECOMES BETTER ESTABLISHED LATER THIS
MORNING.

INGREDIENTS WILL BE IN PLACE FOR A DECENT ACCUMULATING NW FLOW
EVENT. MOISTURE WILL BE DEEP ENOUGH...WITH TEMPS OF -10 TO -12 C AT
THE TOP OF THE MOIST LAYER. ON THE OTHER HAND...THE MOISTURE DEPTH
IS NOT IDEAL AND THE BL FLOW COULD STAND TO BE STRONGER. MOISTURE
WILL ALSO LIKELY BECOME TOO SHALLOW TO SUPPORT GOOD SNOW SHOWER
GENERATION BY LATE EVENING. TWO TO FOUR INCHES LOOKS LIKE A GOOD BET
IN THE USUAL LOCATIONS...WITH SOME LOCALLY HIGHER AMOUNTS POSSIBLE
IN THE HIGHEST ELEVATIONS ALONG THE TENN BORDER. THAT SAID...THIS
DOES NOT APPEAR TO BE A GOOD SETUP FOR SIGNIFICANT VALLEY ACCUMS
SOUTH OF THE I-40...SO THE ADVISORY WILL BE CHANGED TO THE HIGH
ELEVATION VARIETY THIS PACKAGE.

MAX TEMPS WILL BE BELOW NORMAL ONCE AGAIN TODAY (WELL BELOW NORMAL
IN THE MTNS). BELOW NORMAL TEMPERATURES WILL CONTINUE INTO
TONIGHT...ALTHOUGH CONTINUED MIXING IN THE NW FLOW REGIME SHOULD
PREVENT TEMPS FROM REALLY BOTTOMING OUT.

&&

.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 215 AM THU...FLATTENING UPPER FLOW WILL CHARACTERIZE THE SHORT
RANGE PERIOD...AS TROUGH PUSHES OFF THE EAST COAST FRIDAY AND LLVL
RIDGING RETURNS TO THE SOUTHEAST SOON THEREAFTER. THIS RIDGE THEN
SETS UP OVER THE ATLANTIC FOSTERING RETURN FLOW INTO THE SRN
APPALACHIAN REGION. SAID FLOW IS REINFORCED BY THE BROAD FLOW AROUND
LOW PRESSURE EJECTING FROM THE NRN ROCKIES SATURDAY. WEAK UPGLIDE
OCCURS OVER THE OH/TN VALLEYS AS A RESULT...WITH ENOUGH MOISTURE FOR
LIGHT MODEL QPF IN THOSE AREAS SATURDAY. THE ATLANTIC RIDGE IS
PROGGED TO KEEP THIS OFF TO OUR WEST AND WE SHOULD REMAIN DRY THRU
SATURDAY NIGHT. BANDS OF CIRRUS WILL BE SEEN AT TIMES WITH PASSING
POCKETS OF UPPER MOISTURE...AND LOWER CLOUDS INCREASE SLIGHTLY OVER
THE WRN ZONES LATE SATURDAY. THOUGH FRI WILL BE ON THE CHILLY
SIDE...STEADILY RISING LLVL THICKNESSES THRU THE PERIOD SUGGEST
WARMER READINGS FOR SAT AND SAT NIGHT...RETURNING NEAR CLIMO.

&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 135 AM THURSDAY...THE MEDIUM RANGE FCST PICKS UP AT 12Z ON
SUNDAY WITH ANOTHER BROAD H5 TROF DIGGING DOWN OVER THE FAR NORTHERN
STATES AND RELATIVELY FLAT UPPER RIDGING OVER THE SE CONUS. HEIGHTS
WILL LIKELY FALL SOME EARLY NEXT WEEK AS THE UPPER TROF MOVES OVER
THE GREAT LAKES...HOWEVER ALL OF THE ASSOCIATED UPPER ENERGY WILL
REMAIN TO OUR NORTH.

AT THE SFC...HIGH PRESSURE WILL BE CENTERED OFF THE ATLANTIC COAST
WITH SWLY LOW LVL FLOW BRINGING WARMER TEMPS TO THE REGION. THE NEXT
FRONTAL SYSTEM WILL APPROACH THE AREA EARLY MON AND LAY DOWN ACROSS
OUR NORTHERN FRINGE BECOMING A BACK DOOR COLD FRONT OVER THE NEXT 24
HRS OR SO. WELL DEFINED HIGH PRESSURE BEHIND THE FRONT WILL SLIDE
EASTWARD AND SET UP A CAD PATTERN LATER ON TUES AND INTO WED. THE
WEDGE DOESNT APPEAR TO HANG AROUND VERY LONG AS THE LONG RANGE
MODELS SPIN UP A NORTHERN STREAM LOW WHICH PUSHES THE HIGH WELL
OFFSHORE BY LATE WED. THE ECMWF TRIES TO MOVE AN ASSOCIATED COLD
FRONT THRU THE CWFA LATE WED...HOWEVER THE GFS IS MUCH LESS
PROGRESSIVE WITH THIS FRONT AND KEEPS IT TO OUR NORTH. NO
SIGNIFICANT CHANGES WERE NEEDED FOR THE SENSIBLE FCST...WITH ONLY
SLIGHT TO SOLID CHANCE POPS FROM MON ONWARD...WITH THE BEST CHANCES
MOSTLY RELEGATED TO THE HIGHER TERRAIN. TEMPS WILL WARM THRU MON AND
THEN COOL AGAIN AS WE GO INTO MID WEEK AND THE FLOW BECOMES MORE
NELY.

&&

.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
AT KCLT AND ELSEWHERE...LOW VFR CLOUDS WILL REMAIN ACROSS THE AREA
WITH CIGS AT KAVL...AND OCNL CIGS AT KCLT AND KHKY. NWLY GUSTY WINDS
WILL CONTINUE THRU THE AFTERNOON AS WELL. THE CLOUDS AND WINDS WILL
DIMINISH OUTSIDE OF THE MTNS THIS EVENING...BUT WILL CONTINUE AT
KAVL THRU MUCH OF THE NITE...WHERE THEY WILL DIMINISH TOWARD
MORNING. SOME SPRINKLES OR FLURRIES ARE ALSO POSSIBLE AT KAVL THIS
AFTERNOON. LIGHTER NLY WINDS AND INCREASING CIRRUS...AND POSSIBLY
MID CLOUD...WILL DEVELOP FRI.


OUTLOOK...DRY HIGH PRESSURE WILL SET UP OVER THE AREA THROUGH THE
WEEKEND. A COLD FRONT WILL APPROACH FROM THE NORTHWEST EARLY NEXT
WEEK.

CONFIDENCE TABLE...

            17-23Z        23-05Z        05-11Z        11-12Z
KCLT       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KGSP       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KAVL       HIGH 100%     LOW   58%     HIGH 100%     HIGH 100%
KHKY       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KGMU       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KAND       HIGH 100%     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...JPT
NEAR TERM...JDL/RWH
SHORT TERM...WIMBERLEY
LONG TERM...JPT
AVIATION...RWH



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