000
FXUS62 KGSP 071146
AFDGSP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
646 AM EST WED JAN 7 2009
.SYNOPSIS...
A COLD FRONT WILL MOVE EAST ACROSS THE AREA TODAY. HIGH PRESSURE
WILL BUILD OVER THE REGION LATE THURSDAY AND FRIDAY...FOLLOWED BY
ANOTHER COLD FRONT THIS WEEKEND. HIGH PRESSURE IS THEN EXPECTED TO
REBUILD OVER THE AREA LATE SUNDAY AND MONDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
COLD FNT SLOWLY PUSHING INTO THE CWFA FM THE W...AS LO PRES TRIES TO
ORGANIZE OVR THE OH VLY AND SRN GREAT LAKES RGN. WIDESPREAD SHWRS
ACRS THE WRN HALF OF CWFA PRODUCING RAIN RATES OF OVR 0.5"/HR AT
TIMES...W/ SOME AREAS OF MINOR FLOODING OCCURRING ATTM. SO CURRENT
FFA WILL BE LEFT TO CONT. CAD BNDRY FINALLY ADVANCING NWD OVR THE NC
PIEDMONT THIS MORNING. SIGNIFICANT RISE IN TEMPS TO THE MID 60S W/
GUSTY SLY WNDS ON S SIDE OF BNDRY. ALSO STILL GETTING WND GUSTS IN
THE 25-35 MPH RANGE ACRS THE UPSTATE. SO WILL LET LWA CONT TO 6 AM.
COLD FNT FINALLY MAKES IT THRU ERN BORDER OF CWA BY ARND 12-13Z W/
RAIN TAPERING OFF. THERE WILL BE A LULL IN WNDS...AS CAA DOESN/T
REALLY GET GOING TILL ARND MIDDAY. BOTH THE NAM AND GFS SHOW SOLID
45-50 KT AT 850 MB...W/ 1000-850 LAPSE RATES 7.5-8C/KM. SO
DEFINITELY THINK MIXING OF 40 KT GUSTS A GOOD POSSIBILITY ACRS
ENTIRE CWA THIS AFTN. THIS CURRENT HAZARDS STILL VALID...AND TO
AVOID CONFUSION...I WILL START A WIND ADVY FM NOON TO MIDNIGHT
TODAY FOR ENTIRE CWA. THE CRITERIA WILL BE MARGINAL...HWVR...THE
RAINFALL FM LAST COUPLE DAYS WILL LOOSEN SOIL AND MAKE TREES MORE
SUSCEPTIBLE TO FALLING. TEMPS WILL STILL BE MILD W/ THE WARM START
AND DELAYED CAA (SOME MAX TEMPS WILL LIKELY BE THIS MORNING). MAXES
WILL BE IN UPR 40 TO MID 50S MTNS AND UPR 50S TO LWR 60S PIEDMONT.
TONIGHT...WNDS WILL SUBSIDE SOMEWHAT EXCEPT IN THE NRN MTNS (WHERE
TIGHTER PRES GRAD WILL CONT THRU MOST OF THE NGT). THE AXIS OF UPR
TROF WL SWING THRU AREA...W/ POTENT S/W ENERGY. GUIDANCE SHOWS
PLENTY OF MOISTURE BUT WNDS RMNG BACKED TO WLY OR EVEN WSWLY. IT
STILL LUKS LIKE ENUF QPF AND COLD TEMPS FOR AT LEAST 1-2" ALONG THE
TN/NC BORDER. W/ A WND EVENT PRECEDING THE SNOW...WE WILL ISSUE A
WND ADVY FOR THIS AFTN...AND A WINTER WX ADVY FOR THE TN BORDER
COUNTIES FOR THIS EVENING THRU THU AFTN. TEMPS WILL DROP READILY IN
THE CAA TO THE UPR 20S TO LWR 30S MTNS AND MAINLY MID-UPR 30S
PIEDMONT.
&&
.SHORT TERM /THURSDAY THROUGH SATURDAY/...
AS OF 320 AM WEDNESDAY...DEEP TROF LINGERS OVER E US WITH MOIST W TO
NW FLOW CONTINUING OVER THE MTNS THU-THU EVE. MODELS ARE INDICATING
LONGER DURATION OF MOIST UPSLOPE FLOW IN THE COLDER AIR OVER THE NC
MTNS SO BUMPED UP POPS THU AFTN-EVE IN LINE WITH LATEST TRENDS. BY
THE TIME THE MOISTURE MOVES E OF THE N MTNS THU NIGHT...SNOWFALL
TOTALS OF 1-3 INCHES ARE POSSIBLE...MAINLY FOR COUNTIES ALONG THE TN
BORDER.
UPPER TROF MOVES E LATE THU NIGHT-FRI WITH DRY...HIGH PRESSURE
BUILDING OVER THE AREA AT THE SFC. SFC HIGH MOVES E BY FRI AFTN
WHICH PUTS US IN WARM S FLOW. AFTN HIGHS WILL BE A FEW DEG ABOVE
AVG. WARM...MOIST S FLOW PICKS UP FRI NIGHT AND CLOUDS BEGIN TO
INCREASE OVER THE AREA. A FAST MOVG SHORTWAVE AND ASSOC COLD FRONT
APPROACH FROM THE NW SAT BRINGING AN INCREASING CHANCE OF RAIN
SHOWERS TO THE AREA. LOOK FOR HIGHS A COUPLE CATEGORIES ABOVE AVG.
&&
.LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...
AS OF 320 AM WEDNESDAY...MODELS IN POOR AGREEMENT WITH TIMING FOR
THE EXTENDED RANGE BUT H5 SHORTWAVE AND SFC COLD FRONT SHOULD PUSH S
OF AREA SAT NIGHT-SUN WITH AT LEAST A CHANCE OF SHOWERS. EXPECT NEAR
AVG HIGHS SUN-MON AS HIGH PRESSURE BUILDS OVER THE AREA. GFS AND
ECMWF SHOW A BROAD UPPER TROF SETTING UP OVER THE E US WITH A
SHORTWAVE AND ASSOC COLD FRONT DIVING TOWARD THE AREA FROM THE NW
MON NIGHT AND TUE. NOT MUCH MOISTURE EXPECTED WITH THIS SYSTEM BUT
WILL HOLD ON TO SLIGHT CHANCE POPS. LOOK FOR NEAR AVG TEMPS TUE.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
AT KCLT...COLD FRONT HAS PUSHED E PAST THE TERMINAL...WITH JUST SOME
LIGHT SHWRS W/ TEMPO MVFR RESTRICTIONS FOR NEXT COUPLE HOURS. VFR
LVL CLOUDS WILL GENERALLY DECREASE IN COVERAGE...AND VSBY WILL BE
VFR THRU PERIOD. SWLY WINDS WILL INCREASE TO 15-20 KT AROUND
15-16Z...WITH FREQUENT GUSTS OVER 30 KTS POSSIBLE THRU THE AFTN.
WINDS WILL SUBSIDE THIS EVENING AND REMAIN SWLY.
ELSEWHERE...THERE WILL BE SOME LINGERING VERY LIGHT SHWRS THRU 14Z
OR SO. THERE IS STILL POTENTIAL FOR MVFR CIGS SO I THREW IN A TEMPO.
OUTSIDE THE MTNS...SWLY WINDS WILL INCREASE TO 15-20 KT AROUND
15-16Z...WITH FREQUENT GUSTS OVER 30 KTS POSSIBLE THRU THE AFTN. AT
KAVL...THE DIRECTION WILL CHANGE TO NWLY AROUND MIDDAY OR EARLY AFTN
AND BECOME GUSTY INTO THE EVENING. WINDS WILL SUBSIDE THIS EVENING.
OUTLOOK...CONDITIONS SHOULD REMAIN VFR THURSDAY AND FRIDAY WITH
BUILDING HIGH PRESSURE. SATURDAY...A COLD FRONT WILL BRING SHOWERS
INTO THE AREA...WITH THE POTENTIAL OF RESTRICTIONS. DRYING HIGH
PRESSURE BUILDS IN SUNDAY.
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...FLASH FLOOD WATCH THROUGH THIS EVENING FOR GAZ010-017-018.
WIND ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR GAZ010-017-018-
026-028-029.
NC...FLASH FLOOD WATCH THROUGH THIS EVENING FOR NCZ033-048>053-058-
059-062>065-501-503-505-507-509.
WIND ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR NCZ033-035>037-
048>053-056>059-062>065-068>072-082-501>510.
WINTER WEATHER ADVISORY FROM 7 PM THIS EVENING TO 7 PM EST
THURSDAY FOR NCZ033-048>052-058.
SC...FLASH FLOOD WATCH THROUGH THIS EVENING FOR SCZ001>006.
WIND ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR SCZ001>014-019.
&&
$$
SYNOPSIS...RB
NEAR TERM...ARK
SHORT TERM...RB
LONG TERM...RB
AVIATION...ARK