Area Forecast Discussion
Issued by NWS Greer, SC

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000
FXUS62 KGSP 050836
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
336 AM EST FRI FEB 5 2016

.SYNOPSIS...
A COLD FRONT WILL PUSH OFF THE CAROLINA COAST TODAY. LOW PRESSURE IS
EXPECTED TO FORM ON SUNDAY WELL OFFSHORE ALONG THIS FRONT...BRINGING
SHOWERS TO THE LOW COUNTRY. ANOTHER COLD FRONT ARRIVES FROM THE
WEST MONDAY...BRINGING FRIGID CANADIAN AIR INTO THE AREA WHICH
WILL LAST THROUGH MIDWEEK. SNOW SHOWERS WILL BE QUITE POSSIBLE IN
THE MOUNTAINS.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 235 AM...RADAR SHOWING BANDS OF SNOW SHOWERS DEVELOPING ACROSS
THE FOOTHILLS...PIEDMONT AND ERN UPSTATE ATTM AHEAD OF A QUICKLY
MOVING STRONG SHORT WAVE. THIS IS QUITE EXTRAORDINARY...AND SHOWS
JUST HOW COLD THE AIR ASSOCIATED WITH THE WAVE IS...AS SURFACE TEMPS
ARE IN THE UPPER 30S TO AS HIGH AS THE MID 40S...AND SNOW IS STILL
FALLING. EXPECT THE SNOW TO MOVE EAST OF THE AREA BY DAYBREAK AS THE
SHORT WAVE IS QUICKLY MOVING EAST. GIVEN THE LIGHT PRECIP AND
RELATIVELY WARM TEMPS...DO NOT EXPECT ANY ACCUMS ON ROADWAYS AND
ONLY A DUSTING IN GRASSY AREAS AT BEST. SKIES SHUD CLEAR QUICKLY
BEHIND THE DEPARTING SHORT WAVE AS WELL. STRONG AND GUSTY WINDS ARE
ALREADY IN PLACE ACROSS THE MOUNTAINS...SO WILL KEEP THE WIND
ADVISORY IN PLACE. OUTSIDE OF THE ADVISORY...WINDY AND GUSTY
CONDITIONS CAN BE EXPECTED AS WELL...WITH GUSTS NEAR ADVISORY LEVELS
IN THE HIGHER ELEVATIONS OUTSIDE OF THE ADVISORY AREA. BREEZY TO
WINDY AND GUSTY CONDITIONS CAN BE EXPECTED OUTSIDE OF THE MOUNTAINS.
HIGHS WILL BE 5 TO 10 DEGREES BELOW NORMAL.

PRESSURE GRADIENT RELAXES QUICKLY THIS AFTERNOON OR EVENING AS HIGH
PRESSURE BUILDS IN THRU THE NITE. SKIES START OUT CLEAR...BUT SHUD
SEE INCREASING CIRRUS THRU THE NITE. THIS WILL KEEP THE AREA FROM
SEEING PERFECT RADIATIONAL COOLING CONDITIONS. HOWEVER...STILL
EXPECT LOWS TO BE AROUND 5 DEGREES BELOW NORMAL.

&&

.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 245 AM FRI...UPPER HEIGHTS WILL BEGIN TO FALL SATURDAY
MORNING AS PHASED TROUGHS MOVE INTO THE EASTERN CONUS. MODEL
CONSENSUS CONTINUES TO BE THAT THE SRN STREAM SHORTWAVE WILL CUT
OFF SATURDAY NIGHT OVER THE SRN END OF THE APPALACHIANS...RAPIDLY
SPINNING UP A SFC LOW JUST OFF THE SOUTH ATLANTIC COAST. A SMALL
NUMBER OF SREF MEMBERS DO SPREAD SOME OF THE ASSOCIATED PRECIP
INTO THE SRN NC AND SC PIEDMONT...BUT THE REST OF THE CONSULTED
GUIDANCE KEEPS IT SOUTH AND EAST OF OUR CWFA. THESE ARE OUTLIERS
FROM THE OVERALL MODEL ENVELOPE...SO IT SEEMS BEST TO KEEP POPS
BELOW MENTIONABLE VALUES. THESE MINUSCULE CHANCES WILL DECLINE
SUNDAY AS THE LOW DEPARTS THE COAST. HEIGHTS RISE IN THE WAKE
OF THE SYSTEM ONLY BRIEFLY...WITH A MORE SUBSTANTIAL CUTOFF LOW
DIVING INTO THE MISSISSIPPI VALLEY SUNDAY AFTERNOON AND NIGHT. UPPER
DIVERGENCE AND DPVA WILL PROVIDE INCREASING LIFT OVER THE AREA BY
EARLY MONDAY MORNING...AND PRECIP CHANCES INCREASE FROM THE WEST
BY THIS TIME. SFC TEMPS WILL BE COLD ENOUGH TO EXPECT ANY PRECIP
TO FALL AS SNOW...THOUGH CHANCES DO NOT EXPAND BEYOND THE MTNS
BEFORE DAYBREAK.

TEMPS WILL BE ABOUT A CATEGORY BELOW NORMAL SATURDAY AND SATURDAY
NIGHT...TICKING UP SLIGHTLY SUNDAY UNDER GREATER THICKNESSES
BETWEEN THE TROUGHS...AND RETURNING TO NORMAL.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 315 AM FRI...DEEP UPPER TROUGH WILL SETTLE OVER THE EASTERN
CONUS MONDAY...REACHING ITS GREATEST EXTENT TUESDAY MORNING BEFORE
SLOWLY LIFTING TOWARD THE NORTHEAST MID-WEEK. VORT LOBES ROTATING
AROUND THE CLOSED CIRCULATION EMBEDDED WITHIN WILL BRING BOUTS
OF QG FORCING EACH DAY FROM MONDAY TO WEDNESDAY. ARRIVING ARCTIC
AIR WILL CAUSE TEMPS TO TREND DOWNWARD EACH DAY MON-WED...MAXES
AS MUCH AS 15-18 DEGREES BELOW NORMAL.

THE MOST ROBUST BOUT WILL OCCUR DURING THE DAY MONDAY...CONCURRENT
WITH STRONG 700-500MB LAPSE RATES AND DEEP MOISTURE. SOLID
CHANCE TO LIKELY POPS ARE WARRANTED ACROSS THE CWFA MONDAY AFTN
ACCORDINGLY. TEMPS WILL TOP OUT A FEW DEGREES BELOW CLIMO...BUT
NOT EXCEPTIONALLY COLD AT THE SFC. IN THE MTNS PRECIP WILL START
AND END AS SNOW...PERHAPS WITH ENOUGH WARMING DURING THE DAY TO
PERMIT RAIN FOR A TIME. EAST OF THE MTNS...IT WILL BE A LITTLE MORE
TRICKY. PARTIAL THICKNESS P-TYPE TECHNIQUE BASED ON EITHER GFS OR
EC SUGGESTS A TRANSITION FROM RAIN...TO RAIN-SNOW...TO ALL SNOW
OVER THE COURSE OF THE DAY. THE EXPECTED SFC TEMPS HOWEVER DO NOT
SUGGEST MUCH SNOW UNTIL LATE AFTN. THERE IS POTENTIAL FOR WET-BULB
EFFECTS TO SPEED THE TRANSITION EARLIER IN THE DAY...AND THIS IS
ESPECIALLY LIKELY IF CONVECTIVE SHOWERS DO DEVELOP. FOR NOW...WE
WILL ONLY ADVERTISE ACCUMULATING SNOW IN THE MTNS/FOOTHILLS...WHERE
TEMPS ARE MOST CONDUCIVE AND DOWNSLOPING WILL HAVE LESSER IMPACT.

CHANCES TAPER OFF FAIRLY QUICKLY MON EVENING BEHIND THE FIRST SHOT
OF FORCING. THE SUBSEQUENT LOBES TUE AND WED DO NOT BEAR QUITE AS
MUCH POTENTIAL TO PRODUCE SHOWERS EAST OF THE MTNS...MOSTLY DUE
TO A LACK OF MOISTURE AND WEAKER LAPSE RATES. HOWEVER...WITH NW
FLOW BEING AIDED BY THE QG FORCING...THE CHANCE FOR SNOW ALONG
THE TENN BORDER WILL PERSIST MORE OR LESS CONSTANTLY INTO THU.

&&

.AVIATION /09Z FRIDAY THROUGH TUESDAY/...
AT KCLT...GUSTY NLY WINDS AND LOW VFR CIGS WILL CONTINUE THRU
DAYBREAK. STILL EXPECT SOME SCT RAIN/SNOW SHOWERS TO DEVELOP BEFORE
DAYBREAK AS A STRONG SHORT WAVE PASSES THRU. DO NOT EXPECT ANY
SIGNIFICANT ACCUMS. SKIES CLEAR THRU THE MORNING AS THE SHORT WAVE
MOVES EAST AND AND ATMOS DRIES OUT. HOWEVER...STRONGER GUSTY NLY
WINDS WILL CONTINUE THRU THE DAY. WINDS DIMINISH NEAR SUNSET WITH
CLEAR SKIES CONTINUING.

ELSEWHERE...SIMILAR CONDITIONS TO KCLT...BUT WITH STRONGER GUSTY
WINDS AT KAVL AND LIGHTER WINDS AT KAND.

OUTLOOK...LARGE HIGH PRESSURE WILL SLOWLY BUILD ACROSS THE REGION
THROUGH THE WEEKEND WITH UNRESTRICTED CONDITIONS EXPECTED. A STRONG
UPPER AIR DISTURBANCE COULD BRING ENOUGH MOISTURE TO WRING OUT A FEW
RAIN OR SNOW SHOWERS ON MONDAY.

CONFIDENCE TABLE...

            08-14Z        14-20Z        20-02Z        02-06Z
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 100%     HIGH 100%     HIGH 100%     HIGH 100%

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...WIND ADVISORY UNTIL 10 AM EST THIS MORNING FOR NCZ033-049-050-
     501-503-505.
SC...NONE.

&&

$$
SYNOPSIS...WIMBERLEY
NEAR TERM...RWH
SHORT TERM...WIMBERLEY
LONG TERM...WIMBERLEY
AVIATION...RWH


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