000
FXUS62 KGSP 061153
AFDGSP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
653 AM EST TUE JAN 6 2009
.SYNOPSIS...
A STATIONARY FRONT WILL REMAIN ACROSS THE WESTERN CAROLINAS DOWN TO
LOUISIANA THROUGH WEDNESDAY. AREAS OF LOW PRESSURE WILL MOVE
NORTHEAST ACROSS THE FRONT TODAY AND TONIGHT. THE FRONT WILL MOVE
EAST OF THE REGION WEDNESDAY...FOLLOWED BY COOL HIGH PRESSURE UNTIL
THE NEXT FRONT REACHES OUR AREA IN THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
A STATIONARY FRONT...ALONG A LINE FM BATON ROUGE LA...TO
BIRMINGHAM AL...TO THE BLUE RIDGE ESCARPMENT WILL BE THE MAIN WX
FEATURE FOR THE NEAR TERM. STRONG LLVL FORCING AND COPIUS MOISTURE
ALONG AND NORTH OF THE FNT ARE RESULTING IN A LARGE PRECIP
SHIELD...W/ MAINLY LGT-MOD RAIN W/ EMBEDDED HEAVIER ELEMENTS.
GUIDANCE IS IN GENERAL AGREEMNT THAT A PRIMARY SFC WAVE WILL DEVELOP
ALONG THE BNDRY AND TRACK NEWD ALONG THE FNT. THIS WILL ALLOW FOR
THE BNDRY TO LIFT NWD ACRS THE CAROLINAS THRU THE DAY. W/ THE MAIN
AREA OF ISENTROPIC LIFT RMNG NORTH OF THE BNDRY...THE SRN EDGE OF
PRECIP SHIELD SHUD MOVE INTO THE UPSTATE AND SRN PIEDMONT (LEAVING
MAINLY SCT SHWRS). EVEN IF PRECIP ENDS IN THOSE AREAS...IT SHUD RMN
CLOUDY...AS LOW LVLS WILL BE VERY MOIST. WITH THAT SAID...A SOLID
2-4 INCHES OF RAIN ARE EXPECTED IN THE NC MTNS (HIGHEST SW)...W/
LOCALLY HIGHER AMTS. GIVEN THE TRENDS OF HIGHER QPF TO THE N...I
EXPANDED THE FFA TO INCLUDE THE NRN MTNS.
AS LOW PRES DEEPENS INVOF NC MTNS...SFC WNDS MAY INCR
TO 15-20 KTS W/ 20-25 KT GUSTS IN THE WARM SECTOR (UPSTATE AND
POSSIBLY INTO THE CHARLOTTE METRO AREA) LATE IN THE AFTN AND EVE. I
TOOK A BLEND OF GFS/NAM WNDS. TEMPS WILL RMN ABV NORMAL (50S NC
MTNS/FOOTHILLS/NW PIEDMONT AND 60S ELSEWHERE.
AS SFC LOW TRACKS NEWD...THE TAILING FRONT WILL PROGRESS ACRS ERN TN
AND THRU THE FA OVRNGT. A 50-70 KT LLJ AND STRONG FNTL FORCING SHUD
SUPPORT A SOLID LINE OF RAIN ALONG THE FNT. GUIDANCE SHOWS SOME WEAK
CAPE ASSOC W/ CONVECTIVE LINE...AND THERE COULD BE A FEW EMBEDDED
TSTMS. THE MAIN QUESTION IS UPPER SUPPORT...AS ALL GUIDANCE SEEMS TO
KEEP BEST DYNAMICS WELL N AND W OF THE LINE. SO I JUST HAVE A SLGT
CHC TS FOR NOW. IT SHUD BE NOTED THAT EVEN STRONG SHWRS WILL
HAVE THE POTENTIAL TO PRODUCE DAMAGING WINDS GIVEN 50-60 KTS ARND 5
KFT. THE THREAT WILL BE MENTIONED IN THE HWO.
OVRNGT TEMPS WILL BE MILD AHD OF FNT (UPR 40S ACRS THE N AND LWR-MID
50S ALONG AND S OF I-85).
&&
.SHORT TERM /WEDNESDAY THROUGH FRIDAY NIGHT/...
AS OF 315 AM TUESDAY...STRONG LL JET SHOULD MOVE E OF THE AREA EARLY
WED MRNG. UPPER TROF AND ASSOC COLD FRONT PUSH ACROSS CWA DURING THE
DAY WITH THE CHANCE OF SHOWERS DECREASING ACROSS THE PIEDMONT IN THE
AFTN. TEMPS WILL COOL AS COLDER AIR PUSHES IN BEHIND SYSTEM AND
MOISTURE IS EXPECTED TO WRAP AROUND LOW AND INTO THE MTNS WED NIGHT.
USED A GFS/NAM BLEND WHICH INDICATES MOISTURE WILL LACK DEPTH NEEDED
FOR HEAVY SNOWFALL RATES. 850MB FLOW ALSO HAS MORE OF A W COMPONENT
SO SNOWFALL SHOULD BE LIMITED TO ADVSRY CRITERIA OF 1 TO 2 INCHES
WED NIGHT AND THU...MAINLY FOR THE NC MTN COUNTIES ALONG THE TN
BORDER...BEFORE TAPERING OFF AS SYSTEM CONTINUES MOVG NE. DRY...HIGH
PRESSURE BUILDS OVER THE AREA THU NIGHT-FRI WITH TEMPS WARMING TO A
COUPLE DEG ABOVE AVG FRI AFTN.
&&
.LONG TERM /SATURDAY THROUGH MONDAY/...
AS OF 230 AM TUESDAY...DIFFERENCES CONTINUE AMONG THE MEDIUM RANGE
MODELS WITH THE GFS MOVING SYSTEMS FASTER AS COMPARED TO THE ECMWF
WHICH CONTINUES SLOW. TO START THIS PERIOD AT 00Z SATURDAY...BOTH
MODELS HAVE SURFACE HIGH PRESSURE MOVING EAST OFF THE CAROLINA COAST
AS THE NEXT COLD FRONT APPROACHES FROM THE WEST. AT 12Z
SATURDAY...THE GFS HAS THE FRONT AT NASHVILLE AND THE EC HAS IT BACK
AT MEMPHIS. EACH GFS RUN SEEMS TO BE TAKING MOISTURE OUT OF THIS
SYSTEM AND THIS HAS INFLUENCED LOWERING POPS. THE SLIGHT CHANCE OF
FROZEN PRECIP SATURDAY MORNING HAS BEEN SCALED BACK. ONCE THE FRONT
MOVES EAST...THERE IS A LACK OF NORTHWEST FLOW MOISTURE FOR THE NC
MOUNTAINS. THEREFORE...ALMOST COMPLETELY TOOK THE WRAP AROUND SNOW
OUT...ALTHOUGH LEFT JUST A SLIGHT CHANCE FOR THE NORTHERN MOUNTAINS
SATURDAY NIGHT. HIGH PRESSURE BUILDS IN FROM THE WEST ALTHOUGH THE
EC STILL HAS LIGHT PRECIP ALONG OUR SOUTHEAST FRINGE CAROLINA
PIEDMONT AREAS EVEN AT 00Z MONDAY WHICH IS GENERALLY DISREGARDED.
WEAK HIGH PRESSURE BUILDS IN THROUGH MONDAY. THE GFS THEN DEVELOPS
A LOW ON THE CENTRAL GULF COAST LATE MONDAY INTO TUESDAY AS IT
SPREADS MOISTURE TOWARDS US. SO THE GFS HAS THIS SYSTEM MOVING UP
FROM THE SOUTH AND THE NEXT SHORTWAVE COMING DOWN FROM THE GREAT
LAKES TO END THE FORECAST PERIOD. THE EC BRINGS IN THE UPPER TROUGH
WITH MOUNTAIN SNOW HEADING FOR NC FOR THE MID WEEK. THAT IS BEYOND
THE FORECAST HOWEVER.
&&
.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
AT KCLT...IFR CONDITIONS PREVAILING IN STEADY RAIN THRU ABT 16-18Z.
AS A FRONTAL BNDRY BEGINS TO ADVANCE NWD...THE PRECIP SHIELD WILL
SHIFT NORTH THIS AFTN. AS RAIN BECOMES MORE SHOWERY AND
INTERMITTENT...VSBY AND CIGS SHUD IMPROVE (AND COULD BCM VFR BY
MID/LATE AFTN. WNDS WILL BE GENERALLY 5-10 KTS OUT OF THE
S/SW...THEN INCR THIS EVENING AS LO PRES STRENGTHENS TO THE NORTH. A
LINE OF SHWRS (AND POSSIBLY SOME TSTMS) WILL PROGRESS FROM THE W OUT
AHEAD OF AN APPROACHING COLD FRONT. THE LINE IS FCST TO BE IN THE
VICINITY ARND 6Z OR LATER.
ELSEWHERE...RAIN SHIELD OVR AREA...AND VSBYS/CIGS WILL BE GENERALLY
IFR (OCCASIONALLY MVFR) THRU THE MORNING. THIS AFTN...THE BULK OF
RAIN WILL SHIFT NWD ACRS THE TN VALLEY/NC MTNS/MID ATLC...LEAVING
THE UPSTATE WITH JUST MORE SHOWERY ACTIVITY. SO IT IS EXPECTED THAT
CONDS WILL IMPROVE TO AT LEAST MVFR BY MID/LATE AFTN. WNDS WILL BE
GENERALLY LGT OUT OF THE S/SW...THEN INCR TO 12-20 KTS AS LO PRES
STRENGTHENS TO OUR NORTH. A LINE OF SHWRS (AND POSSIBLY SOME TSTMS)
WILL ADVANCE W TO E OUT AHEAD OF AN APPROACHING COLD FRONT. THE LINE
IS EXPECTED TO REACH THE NC MTNS/WRN UPSTATE IN THE 02-05Z TIME
FRAME.
OUTLOOK...A COLD FRONT WILL PUSH INTO THE AREA EARLY WEDNESDAY.
PRECIP WILL END E OF THE MTNS (WITH SHWRS CONTINUING ALONG THE TN/NC
BORDER). CIGS/VSBY WILL IMPROVE BEHIND THE FNT LATER ON
WEDNESDAY...W/ GUSTY WLY WNDS EXPECTED. BREEZY CONDS XPCTD AGAIN ON
THURSDAY...BUT IT SHUD BE DRY THRU FRIDAY.
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...FLASH FLOOD WATCH THROUGH WEDNESDAY EVENING FOR GAZ010-017-018.
NC...FLASH FLOOD WATCH THROUGH WEDNESDAY EVENING FOR NCZ033-048>053-
058-059-062>065-501-503-505-507-509.
SC...FLASH FLOOD WATCH THROUGH WEDNESDAY EVENING FOR SCZ001>006.
&&
$$
SYNOPSIS...DEO
NEAR TERM...ARK
SHORT TERM...RB
LONG TERM...DEO
AVIATION...ARK
