905  
FXUS62 KGSP 202344  
AFDGSP  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC  
744 PM EDT MON OCT 20 2014  
   
SYNOPSIS
 
 
HIGH PRESSURE WILL MOVE OFF THE EASTERN SEABOARD TONIGHT. A WEAK  
COLD FRONT WILL CROSS THE REGION FROM THE NORTHWEST ON TUESDAY. DRY  
HIGH PRESSURE WILL GRADUALLY RETURN MID TO LATE WEEK AND LINGER INTO  
THE WEEKEND.  
 

 
   
NEAR TERM /THROUGH TUESDAY/
 
 
AS OF 730 PM...THE MAIN BAND OF MID-UPR LVL MOISTURE IS CURRENTLY  
CROSSING THE MTNS...WITH A FEW SPOTTY RETURNS ON RADAR. BOTH KAVL  
AND K1A5 REPORTED LIGHT RAIN...BUT LITTLE IF ANY AREAS WILL RECEIVE  
MEASURABLE AMTS. I DID TWEAK POPS TO FOLLOW A SLGT CHC AREA WITH THE  
MOISTURE BAND INTO THE NC FOOTHILLS. OTHERWISE...JUST AN INCREASE IN  
CLOUDS WITH SEASONABLE TEMPS THIS EVENING.  
 
AS OF 500 PM...ONLY A FEW MINOR TWEAKS TO T/TD AND SKY GRIDS HEADING  
INTO THE EARLY EVENING HOURS. OTHERWISE...FCST LOOKS ON TRACK.  
 
AS OF 245 PM EDT...WATER VAPOR IMAGERY SHOWS UPPER LOW SPINNING  
ACROSS LOWER MICHIGAN...WITH THE FIRST S/W BEING PUSHED INTO EASTERN  
KY. THE FIRST WAVE IS ACCOMPANIED BY A BAND OF CIGS CONSISTING OF  
MID LEVEL CLOUDS. THE MODEL PLANE SECTION RH DATA...POINT RH DATA  
AND BUFKIT INFORMATION ALL SHOW THIS SLUG OF MOISTURE CROSSING OUR  
FORECAST AREA TONIGHT. THE MODELS INSIST THAT OUR NRN MOUNTAINS  
COULD STILL SQUEEZE OUT A FEW SPRINKLES...AND WE WILL FOLLOW THAT  
COURSE.  
 
MEANWHILE ONCE THAT FIRST BAND OF CLOUDS PASS...AND BEFORE THE NEXT  
SURFACE FRONT MAKES IT INTO OUR REGION...THERE APPEARS TO BE A  
WINDOW OF OPPORTUNITY WITH LIGHT WINDS AND POTENTIAL FOG DEVELOPMENT  
FOR A FEW HOURS LATE TONIGHT/VERY EARLY TUESDAY MORNING...IN PARTS  
OF THE CENTRAL AND SRN NC RIVER VALLEYS...NE GA AND THE NW PORTIONS  
OF UPSTATE SC. WE WILL ADD FOG TO THIS FORECAST. TEMPERATURES SHOULD  
BE ABOVE READINGS OF LAST NIGHT WITH THE PERIOD OF CLOUDS MOVING  
THROUGH.  
 
THE COLD FRONT WILL CROSS OUR REGION TUESDAY MORNING. NICE  
PERPENDICULAR LOOK OF THE H85 HEIGHT CONTOURS...RELATIVE TO THE H85  
THERMAL PATTERN...SUGGESTS VERY GOOD CROSS CONTOURING...YIELDING  
GUSTY WINDS. UPSLOPE FLOW...ALONG WITH A STRONG 2DRY S/W TUESDAY  
AFTERNOON...WILL HELP WITH THE GENERATION OF SCATTERED SHOWERS.  
 
THE MODELS ARE NOT TOO KEEN ON COLD AIR CU ELSEWHERE...BUT WOULD BE  
SURPRISED IF THEY WERE ABSENT. WE HAVE FOLLOWED AN AVERAGE  
TEMPERATURE FORECAST BASED ON OUR MOST RELIABLE MODEL GUIDE SET.  
 

 
   
SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/
 
 
AS OF 205 PM EDT MONDAY...A STRONG UPPER LOW WILL MOVE OFF THE  
MID-ATLANTIC COAST TUESDAY NIGHT. A SHORT WAVE RIDGE IS FORECAST TO  
BUILD OVER THE SE STATES IN ITS WAKE WED INTO THU. DEEP LAYER N/NW  
FLOW WILL PERSIST THROUGH WED ALONG WITH ASSOCIATED COLD ADVECTION.  
THICKNESSES WILL REBOUND SOME ON THU AS UPPER HEIGHTS INCREASE. DRY  
WEATHER IS EXPECTED THROUGH THU AS THE LOW TO THE NE PULLS AWAY AND  
SURFACE HIGH PRESSURE TO THE NW SLOWLY BUILDS TOWARD THE AREA. THE  
EXCEPTION TO THE TOTALLY DRY FORECAST MAY BE A FEW SPRINKLES IN THE  
NORTHERN MOUNTAINS TUE NIGHT DUE TO UPSLOPE NWLY FLOW. MODEL TIME  
HEIGHTS INDICATE GENERALLY CLEAR CONDITIONS WILL PERSIST EAST OF THE  
MOUNTAINS IN THE DOWNSLOPE FLOW. HOWEVER OVER THE MOUNTAINS TUE  
NIGHT...SOME STRATO CUMULUS CEILINGS ARE LIKELY. MODEL SOUNDINGS  
OVER THE MOUNTAINS INDICATE THAT ENOUGH LOW LEVEL MOISTURE WILL  
PERSIST INTO THU FOR PATCHY CLOUDS.  
 
WINDS WILL BE GUSTY IN THE MOUNTAINS TUE NIGHT AND WED IN THE COLD  
ADVECTION REGIME. COOL AUTUMN TEMPS ARE EXPECTED WITH MAX TEMPS  
5-10 DEGREES BELOW CLIMO ON WEDNESDAY. DESPITE THE COOL REGIME...CURRENT  
INDICATIONS ARE THAT CLOUDS AND/OR WIND WILL PRECLUDE MUCH OF A  
FROST FREEZE CONCERN IN THE MTNS TUE NIGHT...EXCEPT PERHAPS IN THE  
SHELTERED VALLEYS OF THE SOUTHWEST MTNS (WHERE THE FROST/FREEZE  
PROGRAM HAS ALREADY ENDED FOR THE SEASON). WITH WINDS DIMINISHING  
WED NIGHT...A BETTER CASE CAN BE MADE FOR FROST AND AREAS  
OF FREEZING TEMPS. HOWEVER....IT APPEARS THE SW MOUNTAINS WILL BE  
THE COLDEST AGAIN WHILE AREAS ACROSS THE CENTRAL MOUNTAINS WHERE THE  
FROST/FREEZE PROGRAM HAS NOT ENDED MAY STAY MIXED ENOUGH TO PRECLUDE  
ANY FREEZE ISSUES. TEMPS WILL MODEERATE ON THU...BUT REMAIN BELOW  
CLIMO.  
 

 
   
LONG TERM /THURSDAY NIGHT THROUGH MONDAY/
 
 
AS OF 215 PM MONDAY...EVEN THOUGH THE 12Z GFS DEPICTS A RATHER  
VIGOROUS LOOKING UPPER TROUGH MOVING SE THROUGH THE AREA THU NIGHT  
INTO FRI...IT APPEARS THAT THE SYSTEM WILL BE MOISTURE STARVED AND  
HENCE NO PRECIP ASSOCIATED WITH IT. MODEL TIME HEIGHTS INDICATE  
PERHAPS SOME HIGH LEVEL CLOUDINESS ONLY. BEYOND THAT...AN UPPER  
RIDGE IS FORECAST TO MOVE EASTWWARD FROM THE 4-CORNERS AREA TO OVER  
THE EASTERN U.S. BY SUN NIGHT AND THEN OFF THE EAST COAST ON MONDAY.  
SURFACE HIGH PRESSURE WILL DOMINATE THE WEATHER REGIME AS IT  
EVENTUALLY MIGRATES TO OFF THE SE COAST ON MONDAY. DOWNSLOPE FLOW ON  
FRIDAY LOOKS TO OVERCOME THE WEAK COLD ADVECTION ASSOCIATED WITH THE  
UPPER TROUGH AND ALLOW FOR NEAR CLIMO MAX TEMPS. TEMPS WILL THEN  
SLOWLY WARM TO ABOVE CLIMO THE REMAINDER OF THE PERIOD.  
 

 
   
AVIATION /00Z TUESDAY THROUGH SATURDAY/
 
 
AT KCLT AND ELSEWHERE...A BAND OF MID AND HIGH CLOUDS IS CURRENTLY  
CROSSING THE AREA AT TIME OF 00Z TAF ISSUANCE...WITH A FEW SPOTTY  
SPRINKLES AND LIGHT SHWRS SEEN ON RADAR. THESE CLOUDS WILL BRIEFLY  
PRODUCE MID LVL CIGS OF 10 KFT TO 15 KFT. THERE IS A SHARP EDGE TO  
THE CLOUDS/MOISTURE ON SATELLITE...THAT SHUD PASS THRU ON BACK-EDGE  
OF THE MID LVL DISTURBANCE LATE THIS EVENING. FROM THERE...OTHER  
THAN SOME LINGERING LLVL NW FLOW UPSLOPE CLOUDS ALONG TN/NC  
BORDER...SKIES SHUD BE MOSTLY CLEAR. GUIDANCE IS HINTING THAT FOG  
SHUD DEVELOP NEAR LAKES AND STREAMS AND IN THE MTN VALLEYS. I HAVE  
1/2SM VSBY AT KAVL TOWARD DAYBREAK. KAND AND KHKY HAVE A CHANCE OF  
SOME VSBY RESTRICTIONS FROM NEARBY LAKES...BUT CONFIDENCE TOO LOW TO  
MENTION IN TAF. KCLT/KGSP/KGMU SHUD STAY VFR.  
 
ON TUESDAY...A COLD FRONT WILL PASS THRU EARLY MORNING...SHIFTING  
WINDS TO WEST OR WEST-NORTHWEST. THE BETTER COLD ADVECTION/STRONGER  
WINDS LOOK TO WAIT UNTIL LATE AFTN/EARLY EVENING...WITH WINDS  
VEERING TO NORTHWEST OR NORTH-NORTHWEST BY END OF 00Z TAF PERIOD.  
THERE MAY BE SOME STRATOCU DEVELOPMENT LIKE WE SAW TODAY...MAINLY  
ACRS NC. BASES SHUD BE VFR AT ALL TAF SITES...AND GENERALLY FEW TO  
SCT.  
 
OUTLOOK...BLUSTERY AND COOLER FOR THE MIDDLE PART OF THE WEEK...THEN  
WARMING THE LATTER PORTIONS INTO THE WEEKEND. GUSTY MOUNTAIN WINDS  
TUESDAY NIGHT SEEM TO BE THE ONLY AVIATION CONCERN APPARENT AT THIS  
TIME...AS AIR WILL DRY AND WINDS BECOME LIGHT.  
 
CONFIDENCE TABLE...  
 
23-05Z 05-11Z 11-17Z 17-23Z  
KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100%  
KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100%  
KAVL HIGH 100% HIGH 94% HIGH 86% HIGH 100%  
KHKY HIGH 100% HIGH 100% HIGH 91% HIGH 100%  
KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100%  
KAND HIGH 100% HIGH 100% HIGH 94% 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...HG  
NEAR TERM...ARK/TS  
SHORT TERM...LG  
LONG TERM...LG  
AVIATION...ARK  
 
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