Area Forecast Discussion
Issued by NWS Greer, SC

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
165
FXUS62 KGSP 051948
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
248 PM EST FRI FEB 5 2016

.SYNOPSIS...
AN UPPER LEVEL RIDGE AND DRY SURFACE HIGH PRESSURE WILL SLOWLY CROSS
THE FORECAST AREA THROUGHOUT THE WEEKEND. A COLD FRONT WILL PUSH
THROUGH THE REGION ON MONDAY...USHERING IN BELOW NORMAL TEMPERATURES
AND AN INCREASE OF MOISTURE INTO THE MIDDLE OF NEXT WEEK.

&&

.NEAR TERM /THROUGH SATURDAY/...
AS OF 230 PM...WIND HAS DIMINISHED ACROSS THE WESTERN CAROLINAS AND
NORTHEAST GEORGIA...AS HIGH PRESSURE BUILDS IN FROM THE WEST AND THE
PRESSURE GRADIENT RELAXES. OTHERWISE...A SUNNY AFTERNOON WITH TEMPS
SEASONALLY COOL.

THE NEXT 24 HOURS LOOKS RELATIVELY QUIET ACROSS THE WESTERN
CAROLINAS AND NORTHEAST GEORGIA...IN SPITE OF THE APPROACH OF A
VIGOROUS LOOKING UPPER SYSTEM TONIGHT AND ITS ARRIVAL BY LATE
AFTERNOON SATURDAY. HIGH PRESSURE SHOULD MOVE OVERHEAD TONIGHT BUT
WEAKEN. MIN TEMPS WILL BE ON THE ORDER OF FIVE DEGREES BELOW
NORMAL...EVEN WITH DECENT RADIATIONAL COOLING CONDITIONS...OWING TO
THE SOURCE REGION OF THE AIR MASS. ON SATURDAY...THE NEXT SYSTEM
WILL ENCROACH FROM THE WEST IN THE MORNING AND REACH AT LEAST THE
WESTERN HALF OF THE FCST AREA BY THE END OF THE DAY. ALTHOUGH
MID/UPPER FORCING LOOK MORE THAN SUFFICIENT FOR PRECIPITATION...OUR
SOURCES OF MOISTURE ARE COMPLETELY CUTOFF AND UNAVAILABLE. THUS...
EXPECT IT TO REMAIN DRY THIS FAR INLAND. HIGH TEMPS WILL BE COOL
AGAIN AS INCREASING/THICKENING HIGH/MID CLOUDS KEEP TEMPS BELOW
NORMAL AGAIN.

&&

.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
AS OF 235 PM FRI...VERY INTERESTING WEATHER EXPECTED OFF THE
CAROLINA COAST ON SUNDAY. SHORT RANGE MODELS INDICATE THAT A CLOSED
H5 LOW WILL TRACK ACROSS THE DEEP SOUTH SUNDAY MORNING. AT H3...THE
CORE OF A 135 KTS JET WILL LIFT ALONG THE ATLANTIC COAST OF THE
CAROLINAS SUNDAY MORNING. SHORT RANGE MODELS INDICATE THAT SFC LOW
PRESSURE WILL RAPIDLY ORGANIZE AND DEEPEN OFF THE SC COAST BETWEEN
0Z TO 12Z SUNDAY. BY 0Z MONDAY...THE 12Z GFS INDICATES H7 OMEGA
INCREASING TO OVER 150 UBAR/S ON THE WEST SIDE OF THE SFC LOW
CENTER. SIMPLY PUT, THIS ENVIROMENT IS EXPECTED TO RESULT IN
EXPLOSIVE OR BOMB CYCLOGENESIS ON SUNDAY. THE 12Z NAM IS THE MOST
REACTIVE WITH CENTRAL PRESSURE FALLING FROM 1017 MB AT 0Z SUN TO 984
MB AT 21Z SUN. HOWEVER...THE 12Z GFS AND ECMWF INDICATE A VERY
SIMILAR RATE OF PRESSURE FALLS. THIS WOULD MEET OR EXCEED THE
PRESSURE FALL RATE TO QUALIFY AS A BOMB CYCLONE. FORTUNATELY...SHORT
RANGE GUIDANCE KEEPS THE DEEP MOISTURE AND PRECIP ASSOCIATED WITH
THE SYSTEM EAST OF THE FORECAST AREA. HOWEVER...BY MID SUNDAY
AFTERNOON THE PRESSURE GRADIENT MAY RANGE TO 5 MBS...SUPPORTING
GUSTY NORTHWEST WINDS ACROSS THE REGION. THE GRADIENT WILL DECREASE
QUICKLY SUNDAY EVENING AS THE COASTAL LOW RACES OFF TO THE
NORTHEAST. HIGH TEMPERATURES ARE FORECAST TO RANGE FROM THE 40S
ACROSS THE MTNS TO LOW TO MID 50S EAST.

MONDAY...A COLD FRONT ASSOCIATED WITH ANOTHER LOW OVER THE GREAT
LAKES WILL SWEEP OVER THE SOUTHERN APPALACHIANS BY SUNRISE. PRECIP
SHOULD BEGIN AS SNOW ACROSS THE MTNS...GIVEN LOW TEMPS IN THE LOW
30S. HOWEVER...AFTER SUNRISE...TEMPS WILL SLOWLY WARM...CHANGING
PRECIP TO RAIN. BY THE AFTERNOON...TEMPS ARE FORECAST TO RANGE FROM
THE LOW 40S WITHIN THE VALLEY FLOOR TO NEAR 50 EAST. PRECIP WILL
GENERALLY FALL AS LIQUID RAIN. HOWEVER...ELEVATION ABOVE 3500 FEET
MAY REMAIN AS SNOW THROUGH THE AFTERNOON HOURS. BY THE END OF
DAYLIGHT MONDAY...SEVERAL HIGH MTN PEAKS NEAR THE TN LINE MAY SEE A
COUPLE OF INCHES OF SNOWFALL. WE WILL CONTINUE TO HIGHLIGHT IN THE
HWO.

&&

.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
AS OF 215 PM FRIDAY...THE MEDIUM RANGE WILL START OUT MONDAY EVENING
WITH A LARGE UPPER LEVEL VORTEX/TROF OVER THE SOUTHERN GREAT LAKES
AND OH VALLEY...WITH SPOKES OF VORTICITY PIVOTING AROUND THE
CIRCULATION. ONE OF THOSE SPOKES/VORT LOBES WILL CROSS THE CWFA ON
TUESDAY...PRODUCING ANOTHER ROUND OF MODEST MID TO UPPER LEVEL QG
FORCING. HOWEVER...IT DOES NOT LOOK AS IMPRESSIVE...AND MID LEVEL
LAPSE RATES WILL NOT BE AS STEEP AS ON MONDAY. STILL...MOISTURE AND
LIFT ALONG WITH INCREASINGLY BETTER NW UPSLOPE FLOW SHOULD KEEP
SCATTERED TO NUMEROUS SNOW SHOWERS ALONG THE TN BORDER. AS FOR
PRECIP FROM THE BLUE RIDGE AND EAST...MODELS HAVE BACKED OFF ON
PRECIP /BREAKING CONTAINMENT/...SO I WILL ONLY FORECAST A SLIGHT
CHANCE OF RAIN AND SNOW SHOWERS ACROSS THE NC FOOTHILLS AND NW
PIEDMONT. TEMPS WILL BE ABOUT 10-15 DEGREES BELOW NORMAL UNDER THE
TROF.

TUESDAY NIGHT AND BEYOND...THE AXIS OF THE UPPER TROF WILL SWING
EAST OF THE AREA...BUT A LARGE MILLER-B LIKE LOW WILL BE ONGOING
ACROSS THE GREAT LAKES AND THE NORTHEAST. SO A PROLONGED MOIST NW
FLOW WILL CONTINUE ALONG THE TN/NC BORDER...BEFORE TAPERING OFF
WEDNESDAY NIGHT. THE 850 MB TEMPS WILL BOTTOM OUT WEDNESDAY INTO
WEDNESDAY NIGHT...RESULTING IN TEMPS 15-20 DEGREES BELOW NORMAL AND
POTENTIALLY WIND CHILL ADVISORY CONDITIONS IN THE HIGH TERRAIN.
TEMPS START TO REBOUND THURSDAY AND FRIDAY...AS THE EASTERN TROF
STARTS TO FLATTEN OUT. ANOTHER REINFORCING TROF OR WEAK CLIPPER
SYSTEM WILL DIVE INTO THE GREAT LAKES AND OH VALLEY EARLY FRIDAY.
THIS MAY BRING A BRIEF SHOT OF MOISTURE AND NW FLOW SNOW SHOWER
ACTIVITY.

&&

.AVIATION /20Z FRIDAY THROUGH WEDNESDAY/...
AT KCLT AND ELSEWHERE...VFR THROUGH THE PERIOD WITH CLEAR SKY
THRU DAYBREAK SATURDAY. WILL CONTINUE TO HAVE OCCASIONAL GUSTS
THROUGH MID AFTERNOON...BUT THAT SHOULD ABATE BY LATE AFTERNOON.
DIRECTION WILL BE MOSTLY N OR NNW. ON SATURDAY...WIND SHOULD COME UP
FROM THE NE OR ENE BY MID-MORNING...AND HIGH CLOUDS SHOULD INVADE
FROM THE SW AHEAD OF THE NEXT SYSTEM.

OUTLOOK...WEAK HIGH PRESSURE WILL REMAIN ACROSS THE REGION THROUGH
THE WEEKEND. A STRONG UPPER AIR DISTURBANCE COULD BRING ENOUGH
MOISTURE TO WRING OUT A FEW RAIN OR SNOW SHOWERS ON MONDAY.

CONFIDENCE TABLE...

            19-01Z        01-07Z        07-13Z        13-18Z
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...NONE.
SC...NONE.

&&

$$
SYNOPSIS...SBK
NEAR TERM...PM
SHORT TERM...NED
LONG TERM...ARK
AVIATION...PM



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.