Severe Thunderstorm Warning 75, NWS Greenville-Spartanburg, SC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
318 AM EDT SUN MAY 11 2008

.SYNOPSIS...
A STALLED FRONT JUST SOUTH OF THE FORECAST AREA WILL SLOWLY RETURN
NORTH AS A WARM FRONT TODAY. A DEEP LOW PRESSURE SYSTEM MOVING
NORTH OF THE OHIO RIVER VALLEY SUNDAY AFTERNOON WILL DRAG A STRONG
COLD FRONT THROUGH THE SOUTHERN APPALACHIANS LATE SUNDAY. DRY HIGH
PRESSURE WILL BUILD IN FROM THE WEST MONDAY AND TUESDAY. ANOTHER
COLD FRONT WILL APPROACH FROM THE WEST THURSDAY BEFORE STALLING IN
THE VICINITY AND KEEPING CONDITIONS UNSETTLED INTO NEXT WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...
SHOWERS/TSTMS WILL BECOME INCREASINGLY WIDESPREAD FROM UPGLIDE OVER
THE CAD...AND SOUTHEAST UPSLOPE FLOW OVER THE HIGHER TERRAIN AND THE
PIEDMONT FROM THE SW. THUNDER WILL BE MAINLY DUE TO ELEVATED
CONVECTION OVER THE SFC COOL LAYER...BUT THE BOUNDARY IS MAKING
HEADWAY INTO THE EXTREME SW PIEDMONT EARLY THIS MORNING.

AS THE WEDGE FRONT MOVES NE TOWARD THE I-85 CORRIDOR TOWARD
DAYBREAK...STRONG FORCING WILL CROSS THE REGION FROM THE SW. SEVERE
WEATHER WILL INCREASE OVER THE SOUTHEAST PIEDMONT DURING THE MORNING
HOURS AND SPREAD NE ACROSS THE CWA. ANOTHER SHOT OF STRONG
CONVECTION IS THEN EXPECTED THROUGH THE AFTERNOON AS THE TRAILING
COLD FRONT PUSHES THROUGH THE REGION. LOW LEVEL FLOW WILL VEER
SOUTHWEST AHEAD OF THE BOUNDARY AS THE WEDGE CONTINUES TO ERODE FROM
SW TO NE...BUT DEEP LAYER SHEAR WILL BE QUITE STRONG. THIS
SIGNIFICANT SEVERE WEATHER THREAT WILL CONTINUE TO BE HIGHLIGHTED IN
THE HWO.

WESTERLY WINDS WILL COME UP SHARPLY FROM THE WEST WITH PASSAGE OF
THE COLD FRONT LATE IN THE DAY. A HIGH WIND WARNING WILL BE ISSUED
FOR THE N MTNS AND ALONG PART OF THE ADJACENT E MTNS AND
ESCARPMENT...WITH A WIND ADVISORY FOR THE REST OF THE MTNS. A LAKE
WIND ADVISORY WILL BE ISSUED FOR THE PIEDMONT.

WINDS WILL TAPER OFF AT LOWER ELEVATIONS THIS EVE BUT STRONG WINDS
WILL CONTINUE FOR THE MTNS OVERNIGHT. TEMPS WILL COOL SIGNIFICANTLY
AND MORNING LOWS WILL DROP INTO THE UPPER 40S TO AROUND 50 ACROSS
THE PIEDMONT. MID 30S TO MID 40S ARE EXPECTED IN THE MTNS BUT WITH
THE WIND...FROST IS NOT EXPECTED.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 200 AM SUNDAY...GUSTY NORTHWEST WINDS AND SCATTERED UPSLOPE
RAIN SHOWERS WILL PERSIST INTO THE EARLY PART OF MONDAY...AS STRONG
LOW PRESSURE PULLS AWAY FROM THE MID-ATLANTIC COAST. OTHERWISE...
EXPECT A RELATIVELY COOL BEGINNING TO THE WORK-WEEK...AS TEMPS WILL
AVERAGE A COUPLE OF CATEGORIES BELOW CLIMATOLOGY. WINDS AND SHOWER
ACTIVITY WILL DIMINISH BY LATE MONDAY...AS PRESSURE GRADIENT RELAXES
AND MOISTURE PULLS AWAY FROM THE AREA.

HIGH PRESSURE BUILDS INTO THE REGION FOR TUE AND TUE NIGHT...WITH
DRY WEATHER EXPECTED WHILE TEMPS REBOUND TO NEAR-NORMAL LEVELS BY
TUE AFTERNOON.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 205 AM SUNDAY...THE LATTER PART OF THE WEEK APPEARS RATHER
UNSETTLED...AS A NORTHERN STREAM STORM SYSTEM DRAGS A FRONTAL
BOUNDARY INTO THE REGION BEFORE STALLING IT OVER/NEAR THE AREA
UNDERNEATH ZONAL FLOW ALOFT. THE GFS AND ECMWF SUGGEST PERIODIC WEAK
SHORT WAVES WILL LIFT OUT OF THE LOWER MISS VALLEY FROM TIME TO
TIME...POSSIBLY INSTIGATING PERIODIC WEAK CYCLOGENESIS AND SHOWERS
AND STORMS ALONG THE FRONT. WE WILL CONTINUE TO CARRY CHANCE POPS
THROUGH MUCH OF THE EXTENDED RANGE TO ACCOUNT FOR THIS
POSSIBILITY.

&&

.AVIATION /07Z SUNDAY THROUGH THURSDAY/...
STALLED SURFACE BOUNDARY REMAINS S OF AREA EARLY THIS MORNING.
UPSLOPE FLOW OVER THE WEDGE FRONT GETS GOING AROUND 07-08Z SW CWA.
CIGS WILL LOWER QUICKLY INTO THE MVFR RANGE...WITH TEMPO IFR
POSSIBLE TOWARD DAYBREAK IN SHOWERS. TSTMS CHANCES DEPEND ON DEGREE
OF EROSION OF THE COLD WEDGE...WITH KAND THE MOST LIKELY LOCATION
NEARER THE BOUNDARY. AS THE TRAILING COLD FRONT SWEEPS INTO THE
REGION...THUNDER WILL BECOME MORE LIKELY OVER A GREATER PORTION OF
THE AREA AS THE WEDGE QUICKLY ERODES FROM SOUTH TO NORTH.
HOWEVER...COVERAGE WILL LIKELY BE LOWER EXCEPT ALONG A SQUALL LINE
DEVELOPING AHEAD OF THE COLD FRONT. TEMPO THUNDER WILL BE REQUIRED
FOR THIS FEATURE AT SOME POINT THIS AFTN.

NE FLOW IN THE COLD AIR DAMMING REGION WILL STEADILY GIVE WAY TO
GUSTY SOUTHWEST FLOW BY THIS AFTN...WITH G30 KT POSSIBLE AT W TAF
SITES ONCE THE FRONT PASSES. CIGS WILL ONLY SLOWLY RECOVER TO LOW
END VFR VALUES FROM THE SW AS THE FRONT SWEEPS IN AND SHOWERS WILL
REMAIN POSSIBLE INTO THE EVENING AS THE UPPER TROUGH MOVES THROUGH.

OUTLOOK...LINGERING MOISTURE ON STRONG NW FLOW OVER THE MTNS COULD
ALLOW MVFR CIG RESTRICTIONS TO LINGER TONIGHT AT KAVL. WINDS WILL
ALSO TURN WEST THEN NORTHWEST...AND REMAIN VERY GUSTY THROUGH
MONDAY. CONDITIONS WILL STEADILY IMPROVE TUESDAY...WITH SLACKENING
WINDS AND VFR CONDITIONS. DIURNAL THUNDERSTORMS WILL RETURN MID TO
LATE WEEK AS A COLD FRONT MOVES IN FROM THE WEST AND STALLS NEAR THE
SOUTHERN APPALACHIANS.

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...HIGH WIND WATCH FROM LATE TONIGHT THROUGH MONDAY AFTERNOON FOR
     NCZ033-048>053-058-059-062>065-501>507-509.
SC...NONE.

&&

SYNOPSIS...JDL
NEAR TERM...RB
SHORT TERM...JDL
LONG TERM...JDL
AVIATION...RB

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
256 AM EDT SUN MAY 11 2008

GAZ010-017-018-NCZ035>037-056-057-068>072-082-508-510-SCZ001>014-019-
120700-
RABUN-HABERSHAM-STEPHENS-ALEXANDER-IREDELL-DAVIE-CATAWBA-ROWAN-
CLEVELAND-LINCOLN-GASTON-MECKLENBURG-CABARRUS-UNION NC-
GREATER RUTHERFORD-EASTERN POLK-OCONEE MOUNTAINS-PICKENS MOUNTAINS-
GREENVILLE MOUNTAINS-GREATER OCONEE-GREATER PICKENS-
GREATER GREENVILLE-SPARTANBURG-CHEROKEE-YORK-ANDERSON-ABBEVILLE-
LAURENS-UNION SC-CHESTER-GREENWOOD-
256 AM EDT SUN MAY 11 2008

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

.DAY ONE...TODAY AND TONIGHT

THUNDERSTORMS ARE MOVING IN FROM THE SOUTHWEST...MAINLY OVER
PIEDMONT SECTIONS OF NORTHEAST GEORGIA AND THE SOUTHERN UPSTATE OF
SOUTH CAROLINA. AS A WARM FRONT MOVES NORTHWARD TOWARD THE
PIEDMONT...A FEW OF THESE THUNDERSTORMS COULD BECOME SEVERE TOWARD
DAYBREAK. DAMAGING WIND GUSTS AND LARGE HAIL WOULD BE THE MAIN
THREAT FROM ANY THUNDERSTORMS THAT DEVELOP.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY

A STORM SYSTEM WILL APPROACH THE REGION FROM THE TENNESSEE VALLEY
ON SUNDAY...BRINGING WIDESPREAD RAINFALL AND SCATTERED STRONG
THUNDERSTORMS
TO THE AREA. SOME SEVERE THUNDERSTORMS WILL BE POSSIBLE DURING THE
MORNING HOURS...MAINLY IN AREAS SOUTHEAST OF INTERSTATE 85. AS A
STRONG COLD FRONT MOVES IN FROM THE WEST DURING THE AFTERNOON...A
LINE OF STRONG TO SEVERE THUNDERSTORMS WILL REDEVELOP. DAMAGING
WIND GUSTS...LARGE HAIL...AND ISOLATED TORNADOES WILL BE POSSIBLE
ON SUNDAY. LOCATIONS SOUTHEAST OF INTERSTATE 85 WILL BE
ESPECIALLY SUSCEPTIBLE THROUGHOUT THE DAY. VERY WINDY CONDITIONS
WILL LIKELY DEVELOP BEHIND THE COLD FRONT LATE SUNDAY.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL LIKELY BE NEEDED.

NCZ033-048>053-058-059-062>065-501>507-509-120700-
AVERY-MADISON-YANCEY-MITCHELL-SWAIN-HAYWOOD-BUNCOMBE-GRAHAM-
NORTHERN JACKSON-MACON-SOUTHERN JACKSON-TRANSYLVANIA-HENDERSON-
CALDWELL MOUNTAINS-GREATER CALDWELL-BURKE MOUNTAINS-GREATER BURKE-
MCDOWELL MOUNTAINS-EASTERN MCDOWELL-RUTHERFORD MOUNTAINS-
POLK MOUNTAINS-
256 AM EDT SUN MAY 11 2008

...HIGH WIND WATCH IN EFFECT FROM LATE TONIGHT THROUGH MONDAY
AFTERNOON...

THIS HAZARDOUS WEATHER OUTLOOK IS FOR WESTERN NORTH CAROLINA.

.DAY ONE...TODAY AND TONIGHT

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

   HIGH WIND WATCH.

THUNDERSTORMS WILL DEVELOP LATE TONIGHT ACROSS SOUTHWESTERN NORTH
CAROLINA...MAINLY SOUTH OF INTERSTATE 40. CLOUD TO GROUND
LIGHTNING STRIKES WILL BE THE MAIN THREAT...BUT A FEW
THUNDERSTORMS SOUTH OF THE SMOKIES COULD PRODUCE ISOLATED LARGE
HAIL AND DAMAGING WIND GUSTS TOWARD DAYBREAK.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY

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

   HIGH WIND WATCH.

A STORM SYSTEM WILL APPROACH THE REGION FROM THE TENNESSEE VALLEY
ON SUNDAY...BRINGING WIDESPREAD RAIN AND A FEW THUNDERSTORMS TO
THE AREA DURING THE MORNING. A STRONG COLD FRONT WILL THEN CROSS
THE REGION SUNDAY AFTERNOON. A FEW THUNDERSTORMS AHEAD OF THIS
COLD FRONT COULD PRODUCE DAMAGING WIND GUSTS AND LARGE HAIL.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL LIKELY BE NEEDED.

GAZ026-028-029-120700-
FRANKLIN-HART-ELBERT-
256 AM EDT SUN MAY 11 2008

...TORNADO WATCH 304 IN EFFECT UNTIL 10 AM EDT THIS MORNING...

THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTHEAST GEORGIA.

.DAY ONE...TODAY 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.

THUNDERSTORMS ARE MOVING OVER THE PIEDMONT SECTIONS OF NORTHEAST
GEORGIA AND THE SOUTHERN UPSTATE OF SOUTH CAROLINA. AS A WARM
FRONT MOVES NORTHWARD TOWARD THE PIEDMONT...A FEW OF THESE
THUNDERSTORMS COULD BECOME SEVERE TOWARD DAYBREAK. TORNADOES...
DAMAGING WIND GUSTS AND LARGE HAIL ARE POSSIBLE FROM ANY
THUNDERSTORMS THAT DEVELOP.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY

A STORM SYSTEM WILL APPROACH THE REGION FROM THE TENNESSEE VALLEY
ON SUNDAY...BRINGING WIDESPREAD RAINFALL AND SCATTERED STRONG
THUNDERSTORMS
TO THE AREA. SOME SEVERE THUNDERSTORMS WILL BE POSSIBLE DURING THE
MORNING HOURS...MAINLY IN AREAS SOUTHEAST OF INTERSTATE 85. AS A
STRONG COLD FRONT MOVES IN FROM THE WEST DURING THE AFTERNOON...A
LINE OF STRONG TO SEVERE THUNDERSTORMS WILL REDEVELOP. DAMAGING
WIND GUSTS...LARGE HAIL...AND ISOLATED TORNADOES WILL BE POSSIBLE
ON SUNDAY. LOCATIONS SOUTHEAST OF INTERSTATE 85 WILL BE
ESPECIALLY SUSCEPTIBLE THROUGHOUT THE DAY. VERY WINDY CONDITIONS
WILL LIKELY DEVELOP BEHIND THE COLD FRONT LATE SUNDAY.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL LIKELY BE NEEDED.

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
309 AM EDT SUN MAY 11 2008

GAZ017-018-SCZ001-004-110745-
GREATER OCONEE-HABERSHAM-OCONEE MOUNTAINS-STEPHENS-
309 AM EDT SUN MAY 11 2008

...A STRONG THUNDERSTORM WILL AFFECT CENTRAL OCONEE...EASTERN
HABERSHAM AND NORTHERN STEPHENS COUNTIES THROUGH 345 AM EDT...

AT 305 AM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM 3 MILES SOUTH OF TURNERVILLE...OR 6 MILES
NORTHEAST OF CLARKESVILLE...MOVING EAST AT 44 MPH.

* OTHER LOCATIONS AFFECTED INCLUDE BUT ARE NOT LIMITED TO
  TURNERVILLE...HOLLYWOOD...WESTMINSTER...WALHALLA...SENECA AND
  OAKWAY.

MOTHBALL SIZE HAIL...AND WIND GUSTS UP TO 40 MPH ARE EXPECTED WITH
THIS STORM.

LANE