Severe Thunderstorm Warning 12, NWS Greenville-Spartanburg, SC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
250 PM EST WED FEB 18 2009

.SYNOPSIS...
A COLD FRONT WILL CROSS THE SOUTHEAST REGION THIS EVENING AND CROSS
THE ATLANTIC COAST BY THURSDAY AFTERNOON. BEHIND THIS FRONT...HIGH
PRESSURE WILL BUILD OVER THE FORECAST AREA BEGINNING EARLY FRIDAY.
ANOTHER LOW PRESSURE SYSTEM WILL MOVE RAPIDLY FROM THE NORTHWEST
DURING THE WEEKEND.

&&

.NEAR TERM /THROUGH THURSDAY/...
DISCRETE CELLULAR DEEP CONVECTION WELL WEST OF THE MTNS THIS
AFTERNOON EXPECTED TO CONTINUE TO EVOLVE INTO LINEAR SEGMENTS/SQUALL
LINE INTO EARLY EVENING AS SFC COLD FRONT ENCROACHES. WEST ELEVATED
INSTABILITY ACRS THE MTNS/UPSTATE/NE GA THIS AFTERNOON EXPECTED TO
BECOME MORE SFC BASED WITH TIME AS LOWER OVC THINS/AND BREAKS
DEVELOP...ESPECIALLY ACRS THE FAR WESTERN AND SW SXNS OF THE CWFA.
WILL BE MONITORING UPSTREAM TRENDS INTO THIS EVENING FOR
ENCROACHMENT OF STORMS ACCOMPANIED BY GUSTY WINDS INTO THE
AFOREMENTIONED AREAS.

OTHERWISE...A GOOD CHUNK OF THE CWFA EAST OF THE BLUE RIDGE TO
REMAIN IN THE TANK...WITH LOW CIGS AND SCATTERED SHOWERS LINGERING
INTO THE EVENING HOURS. SCOURING COLD FRONT EXPECTED TO PASS
OVERNIGHT WITH DRAMATIC CLEARING EXPECTED. WITH STOUT MID-LVL
JET AXIS DEVELOPING OVERNIGHT...HIGHER ELEVATIONS COULD SEE
STRONG WIND GUSTS...AND AS TEMPS COOL IN THE POST FRONTAL
AIRMASS...SCATTERED TO NUMEROUS TENN BORDER SNOW SHOWERS SHOULD
DEVELOP AS WELL. A GA/NC MTN WIND ADVISORY HAS BEEN HOISTED FOR
THE OVERNIGHT HOURS AS WELL AS A WINTER WX ADVISORY FOR THE
TENN BORDER COUNTIES.

WITHIN THE WELL MIXED POST FRONTAL AIRMASS ON THURSDAY...AS
THE MIXED LAYER DEEPENS...MID LVL WIND MAX MOVES ON OUT...
LIMITED THE POTENTIAL FOR STRONG WIND GUSTS OUTSIDE OF THE
MTNS. A PERIOD OF MODERATE UPSLOPE FLOW WILL CONTINUE TO
THREATEN THE TENN BORDER COUNTIES WILL LOCALIZED ADDITIONAL...
BUT STILL ADVISORY LVL ACCUMULATIONS. NC/GA MTN WIND ADVISORY
TO LAST THROUGH THE DAYLIGHT HOURS...WITH LAKE WIND ADVISORY
CONDITIONS ELSEWHERE.

&&

.SHORT TERM /THURSDAY NIGHT THROUGH SUNDAY/...
AS OF 245 PM WEDNESDAY...CHANCE SNOW SHOWERS WILL CONTINUE IN THE NC
MTNS ALONG TN BORDER THU NIGHT BEFORE TAPERING OFF LATE. SYSTEM WILL
PUSH NE OF AREA FRI WITH DRY...HIGH PRESURE BUILDING IN FROM THE W.
AFTER A COOL START IN THE 20S...WITH A FEW TEENS MTNS...TEMPS WILL
WARM TO AROUND 50 S PIEDMONT...M40S N...WITH M30-L40S MTNS.

HIGH MOVES E FRI NIGHT AND OFFSHORE SAT WITH A LOW PRESSURE SYSTEM
MOVG INTO THE S GREAT LAKES AND AN ASSOC COLD FRONT APPROACHING CWA
FROM THE W. MODELS IN GOOD AGREEMENT SLOWING SYSTEM DOWN SO BACKED
OFF CHANCE POPS UNTIL SAT AFTN OVER NC MTNS...WITH SLIGHT CHANCE
WEST OF MTNS INTO FOOTHILLS. TEMPS WILL BE JUST SLIGHTLY BELOW AVG
SO ANY PRECIP THAT FALLS SHOULD BEGIN AS RAIN.

H5 SHORTWAVE DROPS ACROSS OH VALLEY SAT NIGHT AND HEADS TOWARD CWA.
EXPECT PRECIP TO TURN TO SNOW OVER MTNS SAT EVE...THEN AS THICKNESS
DROPS AND TEMPS CONTINUE TO FALL IN GOOD CAA...CHANCE RAIN WILL TURN
TO CHANCE SNOW ACROSS CWA LATE SAT NIGHT INTO SUN MRNG. CHANCE SNOW
SHOULD CONTINUE OVER NC MTNS IN WRAPAROUND MOISTURE...WHILE TURNING
TO RAIN BEFORE ENDING ACROSS THE PIEDMONT IN THE AFTN. LOOK FOR
HIGHS IN THE L-M40S PIEDMONT...30S MTNS.

&&

.LONG TERM /SUNDAY NIGHT THROUGH TUESDAY/...
AS OF 230 PM WEDNESDAY...THE UPPER TROF AXIS IS EXPECTED TO MOVE OFF
THE EAST COAST SUNDAY NIGHT...LEAVING US WITH A NW FLOW ALOFT INTO
THE EARLY PART OF NEXT WEEK. A SHORT WAVE WILL DROP DOWN TO OUR N
LATE MONDAY OR MONDAY NIGHT...BUT MOISTURE WILL BE TOO LIMITED EVEN
FOR ANY SIGNIFICANT CLOUD COVER. INSTEAD...A LARGE DRY HIGH PRESSURE
AREA WILL CONTROL OUR WEATHER WITH A FLAT UPPER RIDGE BUILDING IN
OVERHEAD ON MONDAY AND MONDAY NIGHT.

BEYOND THAT TIME...CONFIDENCE IS LOW AS THE GUIDANCE DIVERGES
SIGNIFICANTLY. THE GFS AND PREVIOUS ECMWF WERE IN DECENT AGREEMENT
WITH ANOTHER SYSTEM APPROACHING FROM THE WEST TUESDAY NIGHT AND
MOVING IN ON WEDNESDAY...BUT THE NEW ECMWF APPEARS RADICALLY
DIFFERENT...CASTING DOUBT ON THE FORECAST FROM TUESDAY NIGHT ONWARD.
THE FORECAST GENERALLY FOLLOWS THE HPC SOLUTION WITH MOISTURE
RETURNING EARLY WEDNESDAY AND A CHANCE OF PRECIP BY AFTERNOON. WITH
SURFACE TEMPS BELOW FREEZING WEDNESDAY MORNING...THAT COULD RESULT
IN A MINOR PTYPE PROBLEM OVER THE HIGHER TERRAIN IF PRECIP BEGINS
EARLY ENOUGH. CONFIDENCE IS VERY LOW...HOWEVER...SO EXPECT CHANGES
OVER THE NEXT FEW CYCLES.

&&

.AVIATION /20Z WEDNESDAY THROUGH MONDAY/...
AT KCLT...THE LLVL FLOW AND RICH MOISTURE CERTAINLY REMAINS
CONDUCIVE FOR IFR CONDITIONS TO LINGER INTO THE EVENING HOURS
ACCOMPANIED BY ISOLATED TO SCATTERED SHOWERS AND PATCHY LIGHT
RAIN/DRIZZLE. SSW WINDS WITH OCCASIONAL LOW AMPLITUDE GUSTS
WILL DIMINISH SOME THIS EVENING. GENERALLY FOLLOWED MOS GUIDANCE IN
LETTING CONDS BECOME UNRESTRICTED AFTER 06Z. A SHIFT TO NW ALONG
WITH WINDS BECOMING GUSTY IS EXPECTED BY MID-MORNING.

ELSEWHERE ACRS THE FA...SAVE FOR KAVL...WHICH SHOULD MAINTAIN
MVFR CONDITIONS THANKS TO CROSS VALLEY FLOW...IFR CONDITIONS
EXPECTED TO LINGER INTO THE EVENING HOURS WITH GUSTY SOUTHERLY
WINDS. THUNDER CHANCES WILL BE ON THE INCREASE ACRS THE MTNS
AND UPSTATE LATER THIS AFTERNOON AND EVENING BEFORE COLD FRONT
PASSAGE OVERNIGHT AND IMPROVES FLIGHT RESTRICTIONS. GUSTY NW
WINDS WILL BECOME INCREASINGLY COMMON AS THE MORNING WEARS ON.

OUTLOOK...GUSTY NORTHWEST WINDS WILL CONTINUE THURSDAY AFTERNOON
WITH A QUIET WX DAY ON TAP FOR FRIDAY. SHOWERS WILL BE POSSIBLE
SATURDAY AND/OR SATURDAY NIGHT BEFORE ANOTHER COLD FRONT PASSES
DRYING US OUT AGAIN ON SUNDAY.

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...WIND ADVISORY FROM MIDNIGHT TONIGHT TO 5 PM EST THURSDAY FOR
     GAZ010-017.
     LAKE WIND ADVISORY FROM 6 AM TO 5 PM EST THURSDAY FOR GAZ018-
     026-028-029.
NC...WIND ADVISORY FROM MIDNIGHT TONIGHT TO 5 PM EST THURSDAY FOR
     NCZ053-058-059-062>065-501-503-505.
     LAKE WIND ADVISORY FROM 6 AM TO 5 PM EST THURSDAY FOR
     NCZ035>037-056-057-068>072-082-502-504-506>510.
     WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO MIDNIGHT EST
     THURSDAY NIGHT FOR NCZ033-048>052.
SC...LAKE WIND ADVISORY FROM 6 AM TO 5 PM EST THURSDAY FOR
     SCZ001>014-019.

&&

SYNOPSIS...SBK
NEAR TERM...CSH
SHORT TERM...RB
LONG TERM...PAT
AVIATION...CSH

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
337 PM EST WED FEB 18 2009

GAZ018-026-NCZ035>037-056-057-068>072-082-502-504-506>510-SCZ001>010-
012>014-192045-
STEPHENS-FRANKLIN-ALEXANDER-IREDELL-DAVIE-CATAWBA-ROWAN-CLEVELAND-
LINCOLN-GASTON-MECKLENBURG-CABARRUS-UNION NC-GREATER CALDWELL-
GREATER BURKE-EASTERN MCDOWELL-RUTHERFORD MOUNTAINS-
GREATER RUTHERFORD-POLK MOUNTAINS-EASTERN POLK-OCONEE MOUNTAINS-
PICKENS MOUNTAINS-GREENVILLE MOUNTAINS-GREATER OCONEE-
GREATER PICKENS-GREATER GREENVILLE-SPARTANBURG-CHEROKEE-YORK-
ANDERSON-LAURENS-UNION SC-CHESTER-
337 PM EST WED FEB 18 2009

...LAKE WIND ADVISORY IN EFFECT FROM 6 AM TO 5 PM EST THURSDAY...

THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTHEAST GEORGIA...PIEDMONT
NORTH CAROLINA...WESTERN NORTH CAROLINA AND UPSTATE SOUTH CAROLINA.

.DAY ONE...THIS AFTERNOON AND TONIGHT.

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY.

PLEASE LISTEN TO NOAA WEATHER RADIO OR GO TO WEATHER.GOV ON THE
INTERNET FOR MORE INFORMATION ABOUT THE FOLLOWING HAZARDS.

   LAKE WIND ADVISORY.

.SPOTTER INFORMATION STATEMENT...

NONE.

NCZ033-048>052-192045-
AVERY-MADISON-YANCEY-MITCHELL-SWAIN-HAYWOOD-
337 PM EST WED FEB 18 2009

...WINTER WEATHER ADVISORY IN EFFECT FROM MIDNIGHT TONIGHT TO
MIDNIGHT EST THURSDAY NIGHT...

THIS HAZARDOUS WEATHER OUTLOOK IS FOR WESTERN NORTH CAROLINA.

.DAY ONE...THIS AFTERNOON AND TONIGHT.

PLEASE LISTEN TO NOAA WEATHER RADIO OR GO TO WEATHER.GOV ON THE
INTERNET FOR MORE INFORMATION ABOUT THE FOLLOWING HAZARDS.

   WINTER WEATHER ADVISORY.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY.

PLEASE LISTEN TO NOAA WEATHER RADIO OR GO TO WEATHER.GOV ON THE
INTERNET FOR MORE INFORMATION ABOUT THE FOLLOWING HAZARDS.

   WINTER WEATHER ADVISORY.

.SPOTTER INFORMATION STATEMENT...

NONE.

GAZ010-017-NCZ053-058-059-062>065-501-503-505-192045-
RABUN-HABERSHAM-BUNCOMBE-GRAHAM-NORTHERN JACKSON-MACON-
SOUTHERN JACKSON-TRANSYLVANIA-HENDERSON-CALDWELL MOUNTAINS-
BURKE MOUNTAINS-MCDOWELL MOUNTAINS-
337 PM EST WED FEB 18 2009

...WIND ADVISORY IN EFFECT FROM MIDNIGHT TONIGHT TO 5 PM EST
THURSDAY...

THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTHEAST GEORGIA AND WESTERN
NORTH CAROLINA.

.DAY ONE...THIS AFTERNOON AND TONIGHT.

PLEASE LISTEN TO NOAA WEATHER RADIO OR GO TO WEATHER.GOV ON THE
INTERNET FOR MORE INFORMATION ABOUT THE FOLLOWING HAZARDS.

   WIND ADVISORY.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY.

PLEASE LISTEN TO NOAA WEATHER RADIO OR GO TO WEATHER.GOV ON THE
INTERNET FOR MORE INFORMATION ABOUT THE FOLLOWING HAZARDS.

   WIND ADVISORY.

.SPOTTER INFORMATION STATEMENT...

NONE.

GAZ028-029-SCZ011-019-192045-
HART-ELBERT-ABBEVILLE-GREENWOOD-
337 PM EST WED FEB 18 2009

...TORNADO WATCH 25 IN EFFECT UNTIL 11 PM EST THIS EVENING...
...LAKE WIND ADVISORY IN EFFECT FROM 6 AM TO 5 PM EST THURSDAY...

THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTHEAST GEORGIA AND UPSTATE
SOUTH CAROLINA.

.DAY ONE...THIS AFTERNOON AND TONIGHT.

PLEASE LISTEN TO NOAA WEATHER RADIO OR GO TO WEATHER.GOV ON THE
INTERNET FOR MORE INFORMATION ABOUT THE FOLLOWING HAZARDS.

   TORNADO WATCH.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY.

PLEASE LISTEN TO NOAA WEATHER RADIO OR GO TO WEATHER.GOV ON THE
INTERNET FOR MORE INFORMATION ABOUT THE FOLLOWING HAZARDS.

   LAKE WIND ADVISORY.

.SPOTTER INFORMATION STATEMENT...

NONE.