Severe Thunderstorm Warning 183, NWS Greenville-Spartanburg, SC

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
628 PM EST THU DEC 9 2004

.SHORT TERM (REST OF TONIGHT)...
LATEST SFC ANALYSIS SHOWS THAT THE WARM FRONT HAS ADVANCED AS FAR
NORTH AS THE UPPER SAVANNAH RIVER VALLEY. AHEAD OF THE
FRONT...CONDITIONS ARE RIPE FOR THE DEVELOPMENT OF DENSE FOG THIS
EVENING AND TONIGHT. AS THE IN SITU WEDGE WEAKENS AND IS DISPLACED
FURTHER NORTH...THE BL WILL REMAIN VERY MOIST AND STABLE OVERNIGHT.
ATTM PATCHY DENSE FOG HAS BEEN OBSERVED ACROSS THE PIEDMONT OF THE
CAROLINAS. MESOETA SFC CONDENSATION PRESSURE DEFICITS REMAIN LESS
THAN A MB OVER THE NC FOOTHILLS AND PIEDMONT THROUGH 12Z...WILL
EXPECT WIDESPREAD DENSE FOG TO DEVELOP AFTER MIDNIGHT.
ELSEWHERE...THE LLVLS WILL REMAIN WARM AND MOIST
OVERNIGHT...HOWEVER...SFC WINDS SOUTH OF THE WARM FRONT AND AHEAD OF
THE COLD FRONT MAY KEEP THE BL MIXED ENOUGH TO LIMIT WIDESPREAD
DENSE FOG. HAVE ISSUED A DENSE FOG ADVISORY FOR THE NC COUNTIES EAST
OF THE MTNS AND THE EXTREME NRN TIER OF THE SC UPSTATE THROUGH 8 AM
TO HIGHLIGHT. NEW 18Z MAV...DOES ADVERTISE AT LEAST A PERIOD OF
DENSE FOG AT MOST STATIONS...WHICH LOOKS GOOD. WILL ADD PATCHY DENSE
FOG TO THE AREAS OUTSIDE THE WATCH TO THE GRIDS.

THE REST OF THE FORECAST LOOKS GOOD AND WILL LEAVE IT BE. IF NEEDED
WILL COMPLETE ANOTHER UPDATE TO THE FORECAST LATER THIS EVENING.
&&

.PREVIOUS DISCUSSION...
THE FOLLOWING WAS ORIGINALLY ISSUED AT 240 PM EST THU DEC 9 2004

KGSP 88D LOOPS INDICATE BAND OF HVY PCPN CONTINUING TO SHIFT EAST
INTO THE CAROLINA PIEDMONT...WHILE JUST SCATTERED SHOWERS REMAIN IN
IT/S WAKE ACRS THE MTNS. GIVEN THIS PCPN MINIMA ACRS THE FLOOD WATCH
AREA...PLAN TO ALLOW IT TO EXPIRE ON SCHEDULE AT 6 PM. 18Z SFC MAP
SHOWS SUBSTANTIAL 3 HOUR PRESSURE FALLS WITHIN THE WEDGE ACRS THE
CWFA AND AS PCPN CONTINUES TO DIMINISH THROUGH EARLY EVENING...ONE
WOULD THINK THAT THE BNDRY WOULD SHIFT NORTHWARD WITHIN THE MEAN SW
FLOW. ALTHOUGH SHORT RANGE MODELS ARE HAVING TROUBLE PINNING IT
DOWN...LATER TONIGHT...AN INCREASE IN UPPER DIVERGENCE IS LIKELY SO
THE THREAT FOR SHOWER DEVELOPMENT...PERHAPS WIDESPREAD AGAIN WILL BE
ON THE INCREASE.

WILL PROGRESSIVELY DECREASE POPS THROUGH THE DAY FRIDAY AS LINGERING
MOISTURE STRUGGLES WITH EVER DECREASING AMOUNT OF LARGE SCALE LIFT.
GRADIENT EXPECTED TO TIGHTEN AS WELL...ESPECIALLY IN THE AFTERNOON
IN THE WAKE OF THE COLD FRONT. HIGHER ELEVATION ACCUMULATING SNOW
SHOWER THREAT STILL QUITE APPARENT FRI NIGHT AND/OR SATURDAY WITH
THE COMBINATION OF MOIST NW FLOW AND MID-LVL TROUGH SWINGING
THROUGH. MTN SNOW SHOWER CHANCES DECREASE SAT NITE AND NW FLOW
WANES WITH A QUIET SUNDAY EXPECTED WITH BACKING BUT DRY FLOW
AHEAD OF APRCHG ARCTIC FRONT
&&

LONG TERM (SUNDAY NIGHT THROUGH THURSDAY)...
A SERIES OF SHORT WAVES WILL CARVE OUT ANOTHER EASTERN L/WV TROUGH
BY MID WEEK...ALLOWING THE COLDEST AIR OF THE YEAR TO SURGE INTO THE
SOUTHEAST STATES BY TUESDAY. TEMPERATURES MAY STRUGGLE TO GET OUT OF
THE 30S TUESDAY AND WEDNESDAY ACROSS THE MOUNTAINS...WHILE DOWNSLOPE
FLOW SHOULD SOMEWHAT MITIGATE THE STRONG COLD ADVECTION EAST OF THE
BLUE RIDGE. PERSISTENT NORTHWEST FLOW WILL RESULT IN PERIODS OF
UPSLOPE SNOW SHOWERS ALONG THE TENN BORDER...OTHERWISE THE FORECAST
WILL REMAIN DRY THROUGH THE PERIOD.
&&

AVIATION...
THE HEAVY RAIN BAND MOVING ACROSS THE REGION ATTM SHOULD CLEAR KGSP
AND KHKY BY 21Z...AND KCLT BY 23Z. IFR CONDITIONS WILL ACCOMPANY THE
RAIN BAND...BUT VISBY SHOULD IMPROVE TO MVFR ONCE THE BAND MOVES
EAST. PLENTIFUL LOW LEVEL MOISTURE WILL LINGER ACROSS THE AREA INTO
TOMORROW...SO VCSH WILL BE CARRIED THROUGH THE OVERNIGHT HOURS.
VISBY AND CEILING TONIGHT WILL DEPEND LARGELY ON HOW FAR NORTH THE
WARM FRONT RETREATS OVERNIGHT. THE WIDESPREAD RAIN HAS LOCKED IN A
COLD POOL ACROSS THE AREA THIS AFTERNOON...WITH THE FRONT MORE OR
LESS STALLED JUST TO OUR SOUTH. BEST GUESS ATTM IS THAT THE BOUNDARY
WILL RESUME A SLOW NORTHWARD MOVEMENT ONCE THE RAIN HAS CLEARED THE
AREA...AND THAT ALL SITES EXCEPT KHKY WILL BE IN THE WARM SECTOR BY
MORNING. THE TAFS FEATURE MVFR FOG W/ IFR CEILINGS AT TERMINALS
EXPECTED TO BE SOUTH OF THE BOUNDARY OVERNIGHT...BUT WILL MAINTAIN
IFR CONDITIONS AT KHKY THROUGH MID MORNING.
&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...DENSE FOG ADVISORY FOR ZONES NCZ034-035-037-038-054>057-
     066>072-082 UNTIL 8 AM FRIDAY MORNING.
SC...DENSE FOG ADVISORY FOR ZONES SCZ008-009-014 UNTIL 8 AM
     FRIDAY MORNING.
&&

SHORT TERM (UPDATE)...NED

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
310 PM EST THU DEC 9 2004

GAZ010-017-018-026-028-029-NCZ033>037-048>059-062>072-082-SCZ001>014-
019-101100-
ABBEVILLE SC-ALEXANDER NC-ANDERSON SC-AVERY NC-BUNCOMBE NC-BURKE NC-
CABARRUS NC-CALDWELL NC-CATAWBA NC-CHEROKEE SC-CHESTER SC-
CLEVELAND NC-DAVIE NC-ELBERT GA-FRANKLIN GA-GASTON NC-GRAHAM NC-
GREATER GREENVILLE SC-GREATER OCONEE SC-GREATER PICKENS SC-
GREENVILLE MOUNTAINS SC-GREENWOOD SC-HABERSHAM GA-HART GA-HAYWOOD NC-
HENDERSON NC-IREDELL NC-LAURENS SC-LINCOLN NC-MACON NC-MADISON NC-
MCDOWELL NC-MECKLENBURG NC-MITCHELL NC-NORTHERN JACKSON NC-
OCONEE MOUNTAINS SC-PICKENS MOUNTAINS SC-POLK NC-RABUN GA-ROWAN NC-
RUTHERFORD NC-SOUTHERN JACKSON NC-SPARTANBURG SC-STEPHENS GA-
SWAIN NC-TRANSYLVANIA NC-UNION SC-UNION NC-YANCEY NC-YORK SC-
310 PM EST THU DEC 9 2004

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

.DAY ONE...

SCATTERED TO NUMEROUS SHOWERS WILL LINGER THROUGH TONIGHT. HEAVY
SHOWERS AND PERHAPS A THUNDERSTORM WILL BE SEEN AS WELL. HEAVY RAIN
EARLIER TODAY WILL CONTINUE TO RESULT IN HIGH WATER CONDITIONS IN A
FEW SPOTS.

.DAYS TWO THROUGH SEVEN...

SCATTERED TO NUMEROUS SHOWERS WILL CONTINUE ON FRIDAY.  AS COLD AIR
FILTERS INTO THE REGION BEHIND THE COLD FRONT...THE RAIN SHOWERS WILL
TRANSITION TO SNOW SHOWERS IN THE HIGHER ELEVATIONS OF THE MOUNTAINS
FRIDAY NIGHT.  SCATTERED SNOW SHOWERS WILL CONTINUE IN THE MOUNTAINS
WITH NORTHWEST FLOW ON SATURDAY.  THESE SNOW SHOWERS WILL GRADUALLY
DECREASE AS THE MOISTURE FEED DECREASES TOWARD THE END OF THE DAY.
THE LAST LOCATIONS TO SEE SNOW SHOWERS WILL BE IN THE TENNESSEE
BORDER LOCATIONS SATURDAY NIGHT.

FOR MORE INFORMATION ON THE EXPECTED SNOWFALL...SEE CAESPSGSP.

SCATTERED RAIN AND SNOW SHOWERS ARE AGAIN POSSIBLE IN THE NORTHERN
MOUNTAINS ON MONDAY.

NEXT WEEK WILL HAVE MUCH BELOW NORMAL TEMPERATURES.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT ANTICIPATED.

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
751 PM EST THU DEC 9 2004

GAZ026-028-029-SCZ010>012-019-100900-
ABBEVILLE SC-ANDERSON SC-ELBERT GA-FRANKLIN GA-GREENWOOD SC-HART GA-
LAURENS SC-
751 PM EST THU DEC 9 2004

...SEVERE WEATHER OUTLOOK...

A WARM FRONT WILL MOVE GRADUALLY NORTHWARD OVER THE SAVANNAH RIVER
VALLEY AND INTO THE UPSTATE OF SOUTH CAROLINA THROUGH LATE TONIGHT.
THE AIR MASS TO THE SOUTH OF THE WARM FRONT WILL BE SOMEWHAT UNSTABLE
OVERNIGHT WITH MUCH WARMER AND MORE HUMID AIR AT THE SURFACE. WIND
SHEAR WILL ALSO INCREASE LATER THIS EVENING.

SCATTERED THUNDERSTORMS WILL DEVELOP IN THE AIR MASS TO THE SOUTH OF
THE WARM FRONT OVERNIGHT. THERE IS A SMALL POSSIBILITY THAT A FEW OF
THE THUNDERSTORMS COULD PRODUCE SEVERE WEATHER IN FORM OF WIND DAMAGE
OR AN ISOLATED TORNADO...GIVEN THE EXPECTED STRENGTH OF THE WIND
SHEAR. WHAT REMAINS TO BE SEEN IS HOW FAR NORTH THE WARM FRONT WILL
MOVE OVERNIGHT...WHICH IS KEY TO THE SEVERE WEATHER POTENTIAL FOR
EXTREME NORTHEAST GEORGIA AND THE LOWER PIEDMONT REGION OF SOUTH
CAROLINA.

PRESENT INDICATIONS ARE THAT THE WARM FRONT WILL MOVE INTO THE AREA
FROM ELBERTON TO ABBEVILLE AND GREENWOOD BY LATE TONIGHT. THUS...A
POTENTIAL EXISTS FOR SEVERE THUNDERSTORMS ALONG AND IMMEDIATELY NORTH
OF THE WARM FRONT BOUNDARY...INTO THE AREA FROM HARTWELL TO ANDERSON
AND LAURENS...THROUGH LATE TONIGHT.

SPOTTER GROUPS SHOULD BE PREPARED TO ACTIVATE QUICKLY LATE THIS
EVENING AND OVERNIGHT. DISPATCHERS SHOULD ENSURE COUNTY
EMERGENCY MANAGEMENT OFFICIALS ARE AWARE OF THIS INFORMATION.

STAY TUNED TO NOAA WEATHER RADIO OR THE MEDIA FOR THE LATEST WEATHER
INFORMATION OR SEVERE WEATHER WATCHES OR WARNINGS.

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