638  
FXUS62 KGSP 011105  
AFDGSP  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC  
705 AM EDT SAT NOV 1 2014  
   
SYNOPSIS
 
 
A DEEP UPPER LOW PRESSURE SYSTEM WILL CROSS THE AREA FROM THE  
WEST TODAY. THIS SYSTEM WILL BE ACCOMPANIED BY COLD TEMPERATURES  
AND VERY WINDY CONDITIONS. DRY AND COLD HIGH PRESSURE WILL RETURN  
SUNDAY THROUGH EARLY NEXT WEEK.  
 

 
   
NEAR TERM /THROUGH TONIGHT/
 
 
AS OF 6 AM...AN AREA OF LIGHT TO MODERATE PRECIP CONTINUES TO PIVOT  
ACROSS UPSTATE SC AS THE UPPER LOW MOVES DOWN ACROSS THE SRN  
APPALACHIANS. AS EARLIER FEARED...PRECIPITATION RATE HAS BEEN HIGH  
ENOUGH IN SOME OF THE GREENVILLE METRO AREA TO BRING THE FREEZING  
LEVEL DOWN VERY CLOSE TO THE SFC...IN PARTICULAR THE AREA FROM THE  
WEST SIDE OF GREENVILLE THROUGH TRAVELERS REST AND NEAR PARIS MTN.  
THE TEMPS CONTINUE TO FALL ACROSS THE AREA FROM GREENVILLE TO THE  
LAKELANDS...WITH PRECIP CHANGING OVER TO WET SNOW NOW S OF I-85 DOWN  
THROUGH GREENWOOD AND ABBEVILLE. HAVE SINCE EXPANDED THE WINTER WX  
ADVISORY FOR MUCH OF THE REST OF THE UPSTATE FROM I-26 WEST WHERE  
THE BEST PRECIP AREA CONTINUES TO ROTATE AROUND THE UPPER LOW. THE  
PRECIP SHOULD CHANCE BACK OVER TO RAIN THROUGH MID MORNING AS TEMPS  
START TO WARM. FORTUNATELY...MOST OF THE SNOW WILL MELT ON CONTACT  
WITH ROAD SURFACES. THIS REMAINS A DYNAMIC SITUATION SO ADDITIONAL  
UPDATES ARE POSSIBLE.  
 
THE UPPER LOW SHOULD PASS OVERHEAD THROUGH THE MORNING HOURS WITH  
ALL MANNER OF LOW/MID/HIGH UPPER FORCING COMING INTO PLAY. HAVE  
RAISED/EXPANDED THE PRECIP PROBABILITY THROUGH THE MORNING HOURS.  
CANNOT RULE OUT A CHANGEOVER TO WET SNOW ACROSS THE NC  
FOOTHILLS/UPSTATE AS THE COLDER AIR SPILLS DOWN FROM THE MTNS. A  
MIX/CHANGEOVER ACTUALLY APPEARS A BIT LESS OF A POSSIBILITY OVER  
METRO CLT AS THE MODEL TREND WAS A BIT WARMER THIS MORNING.  
HOWEVER...AS WE ARE SEEING CURRENTLY OVER GSP...IF THE PRECIPITATION  
FALLS WITH ENUF INTENSITY...SOME WET SNOW COULD MAKE IT TO THE  
GROUND. THE UPPER LOW SHOULD PULL A QUICK EXIT OFF TO THE EAST  
DURING THE MIDDLE PART OF THE DAY...BRINGING THE LOW LEVEL WINDS  
AROUND TO A N TO NW DOWNSLOPE AFTER 15Z...WHICH SHOULD START TO  
DIMINISH PRECIP POTENTIAL NEAR THE BLUE RIDGE/WRN UPSTATE. AS THE  
LOW MOVES AWAY...SOME WRAP AROUND DEFORMATION MAY LINGER OVER THE  
WRN PIEDMONT INTO THE AFTERNOON...BUT THAT SHOULD ALSO DIE OFF AND  
MOVE EAST BY LATE AFTERNOON. MEANWHILE...THE MTNS WILL UNDERGO A  
TRANSITION TO A MORE PURE NW FLOW PRECIP EVENT...WHICH WILL MAINLY  
BE SNOW. WILL MAINTAIN A HIGH PRECIP CHANCE NEAR THE TN BORDER...AND  
TAPER IT OFF EASTWARD FROM THERE.  
 
WE SHOULD CONTINUE TO DRY OUT EVERYWHERE E OF THE SPINE OF THE  
APPALACHIANS THIS EVENING AND TONIGHT. HOWEVER...THE NW FLOW SNOW  
WILL CONTINUE INTO TONIGHT ALONG THE TN BORDER. THIS MAY REQUIRE  
EXTENDING THE WINTER STORM WARNING THROUGH THIS EVENING. WIND GUSTS  
SHOULD ABATE ENUF AROUND SUNSET THAT WE CAN KEEP THE SAME EXPIRATION  
TIME ON THE WIND ADVISORY. AS FOR THE FREEZE WATCH...FCST LOWS ARE  
SUCH THAT WE CAN ROLL THAT OVER TO A FREEZE WARNING. THE WARNING  
WILL HAVE TO BE EXPANDED INTO THE NRN FOOTHILLS OF NC BASED ON THE  
MIN TEMP FCST. HENDERSON COUNTY NC WILL BE LEFT OUT AS THE FROST/  
FREEZE PROGRAM ENDS 1 NOVEMBER AS A MATTER OF POLICY.  
 

 
   
SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/
 
 
AS OF 300 AM EDT SAT...A DEEP UPPER LOW PRESSURE TROUGH OFF THE  
CAROLINAS COAST 12Z SUN WILL LIFT NNE INTO THE MAINE COAST BY 00Z  
MON...LEAVING THE CWA UNDER NWLY FLOW ALOFT ON SUN. H5  
HEIGHTS/THICKNESSES RISE CONSIDERABLY BY MON AS AN UPPER RIDGE  
BUILDS IN FROM THE WEST. THE UPPER RIDGE AXIS IS FORECAST TO REACH  
OUR REGION BY MON NIGHT.  
 
AT THE SURFACE...1030MB SURFACE HIGH WILL BUILD IN FROM THE NW SUN  
AND BECOMES CENTERED OVER THE SE STATES BY MONDAY. ANY LINGERING NW  
PRECIP ALONG THE TN BORDER LINE SHOULD TAPER OFF BY SUN MORNING AS  
DRY AIRMASS MOVES IN. WITH PREVAILING CAA NW FLOW ON SUN...TEMPS  
SHOULD REMAIN AROUND 10-15 DEGREES BELOW NORMAL. LATEST GUIDANCE  
SUGGESTS THAT SUB-FREEZING TEMPS ARE EXPECTED OVER MUCH OF  
THE CWA ON SUN NIGHT. THEREFORE...ANOTHER FREEZE WATCH MAY BE NEEDED  
OVER EAST OF THE MTNS FOR THIS PERIOD.  
 
AS MODIFYING HIGH PRESSURE CENTERED OVER THE REGION SHIFTS EAST  
THROUGH MONDAY NIGHT...WINDS WILL VEER TO THE SW AND TEMPS SHOULD  
WARM UP BY MORE THAN 10 DEGREES BY MON AFTERNOON IN ITS WAKE.  
CONDITIONS SHOULD REMAIN DRY UNDER THE HIGH PRESSURE MON.  
 

 
   
LONG TERM /TUESDAY THROUGH FRIDAY/
 
 
AS OF 230 AM EDT SAT...LATEST GLOBAL MODELS CONTINUE TO AGREE  
THAT AN UPPER RIDGE AXIS OVER THE EASTERN STATES WILL SHIFT  
OFFSHORE BY TUE NIGHT AS A POSITIVELY TILTED UPPER TROUGH  
APPROACHES FROM THE CENTRAL CONUS. THIS TROUGH IS FORECAST TO  
CROSS THE EASTERN CONUS BETWEEN WED NIGHT AND THU...OFF THE  
ATLANTIC COAST BY EARLY FRI.  
 
AT THE SURFACE...A MODIFYING HIGH PRESSURE CENTERED OVER THE SE  
STATES WILL GRADUALLY SHIFT OFFSHORE TUE INTO WED AS A WEAK COLD  
FRONT APPROACHES FROM THE WEST. THE FRONT SHOULD CROSS THE REGION  
LATE WED INTO THU...OFF TO OUR EAST BY THU NIGHT. IT STILL APPEARS  
THAT THE FRONT WILL BE MOISTURE STARVED. HENCE...HAVE INHERITED  
SLIGHT CHANCE POPS OVER THE PIEDMONT WITH LOW END CHANCE MANLY OVER  
THE WESTERN ZONES OF THE MTNS WED AFTERNOON THRU THU MORNING.  
CONDITIONS LOOK DRY THU NIGHT AND FRI AS A COOL HIGH PRESSURE BUILDS  
IN FROM THE WEST. MODES SUGGEST THAT THERE COULD BE LIGHT NW PRECIP  
(A MIX OF RAIN AND SNOW) BEHIND THE DEPARTING FRONT ALONG THE TN  
BORDER THU NIGHT INTO FRI. SO HAVE KEPT SLIGHT CHANCE FOR RN/SN  
THERE THRU FRI MORNING. TEMPS SHOULD START OUT AROUND 3-5 DEGREES  
BELOW NORMAL TUE...WARMING UP TO NEAR NORMAL BY WED. TEMPS THEN COOL  
OFF BY 5-7 DEGREES BY FRI IN THE WAKE OF THE FROPA.  
 

 
   
AVIATION /11Z SATURDAY THROUGH WEDNESDAY/
 
 
AT KCLT...PATCHES OF LIGHT RAIN WILL ROTATE AROUND THE UPPER LOW AND  
ACROSS THE AIR FIELD THROUGH THE MID MORNING HOURS. THIS WILL KEEP  
THE CEILING VARIABLE BETWEEN THE LOW END OF MVFR AND THE UPPER END  
OF IFR THROUGH AT LEAST 14Z. CONDITIONS SHOULD IMPROVE A BIT TO  
WHERE IFR IS NO LONGER LIKELY...UNLESS HEAVIER PRECIP FALLS. AT THIS  
POINT...STILL THINK PRECIP TYPE WILL REMAIN ALL RAIN. BY THE TIME  
STEADIER PRECIP AROUND THE UPPER LOW ROTATES EWD OVER KCLT...THE  
TEMPS SHOULD WARM ENUF TO KEEP IT ALL RAIN. WIND WILL REMAIN NW TO N  
THROUGH THE MORNING HOURS WITH OCNL GUSTS...WHICH MAY BECOME MORE  
FREQUENT THROUGH THIS AFTERNOON. AS THE UPPER LOW MOVES PAST DURING  
MIDDAY...CONDITIONS SHOULD START TO IMPROVE. EXPECT VFR CONDITIONS  
AFTER ABOUT 19Z WITH CLEARING AROUND SUNSET. WIND GUSTS SHOULD ABATE  
BY THEN WITH WIND REMAINING NW.  
 
ELSEWHERE...A MESS FIRST THING THIS MORNING WITH SNOW POSSIBLE AT  
KGMU AND KAND...IN ADDITION TO KAVL. STILL EXPECT THE GREATEST  
IMPACT AT KAVL. ANY PRECIP THAT FALLS SHOULD MAINLY BE IN THE FORM  
OF SNOW...AND SHOULD REDUCE VSBY TO MVFR OR IFR RANGE. WILL KEEP A  
TEMPO IFR FOR THE SNOW FOR THE FIRST PART OF THE TAF BASED ON RADAR  
TREND... AND THIS WILL PROBABLY BE MOVED FORWARD IN TIME WITH EACH  
SUCCESSIVE AMEND. THE LOW CLOUDS AND PRECIP WILL PERSIST THROUGH THE  
DAY AT KAVL...BUT MOVE OUT E OF THE MTNS AROUND MIDDAY.  
 
OUTLOOK...DRYING HIGH PRESSURE WILL BUILD IN LATE THIS WEEKEND AND  
CONTINUE THROUGH EARLY NEXT WEEK...BRINGING VFR CONDITIONS.  
 

 
   
GSP WATCHES/WARNINGS/ADVISORIES
 
 
GA...WINTER WEATHER ADVISORY UNTIL 8 PM EDT THIS EVENING FOR GAZ010-  
017.  
WIND ADVISORY UNTIL 8 PM EDT THIS EVENING FOR GAZ010-017.  
FREEZE WARNING FROM MIDNIGHT EDT TONIGHT TO 9 AM EST SUNDAY  
FOR GAZ010-017-018-026-028-029.  
FREEZE WARNING UNTIL 10 AM EDT THIS MORNING FOR GAZ010.  
NC...WINTER WEATHER ADVISORY UNTIL 8 PM EDT THIS EVENING FOR NCZ053-  
059-062>065-501-503-505-507-509.  
WIND ADVISORY UNTIL 8 PM EDT THIS EVENING FOR NCZ033-035-  
048>053-058-059-062>065-501>510.  
FREEZE WARNING FROM MIDNIGHT EDT TONIGHT TO 9 AM EST SUNDAY  
FOR NCZ035-056-068-069-501>510.  
WINTER STORM WARNING UNTIL 8 PM EDT THIS EVENING FOR NCZ033-  
048>052-058.  
FREEZE WARNING UNTIL 10 AM EDT THIS MORNING FOR NCZ033-049-050-  
053-063>065.  
SC...WINTER WEATHER ADVISORY UNTIL 8 PM EDT THIS EVENING FOR SCZ003.  
WIND ADVISORY UNTIL 8 PM EDT THIS EVENING FOR SCZ001>003.  
FREEZE WARNING FROM MIDNIGHT EDT TONIGHT TO 9 AM EST SUNDAY  
FOR SCZ001>008-010>013-019.  
WINTER WEATHER ADVISORY UNTIL 11 AM EDT THIS MORNING FOR  
SCZ002-005>007-010>012-019.  
 

 
 

 
SYNOPSIS...JOH  
NEAR TERM...PM  
SHORT TERM...JOH  
LONG TERM...JOH  
AVIATION...PM  
 
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