Special Weather Statement, NWS Greenville-Spartanburg, SC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
257 PM EDT MON AUG 8 2011

.SYNOPSIS...
A WEAK FRONTAL BOUNDARY ALONG WITH A HOT AND HUMID AIRMASS WILL
LINGER ATOP THE REGION INTO TUESDAY. DRIER HIGH PRESSURE WILL BUILD
OVER THE AREA ON WEDNESDAY. ANOTHER FRONT WILL ENTER THE AREA ON
SATURDAY, BRINGING A CHANCE FOR RAIN AND THUNDERSTORMS.

&&

.NEAR TERM /THROUGH TUESDAY/...
THE NEXT 24 HOURS SHOULD BE CONVECTIVELY ACTIVE...WITH ONE BROKEN
LINE OF CONVECTION CONSOLIDATING IN ERN TN/WRN NC AT 19Z AND THE
POSSIBILITY OF MORE LATE TONIGHT. HAVE DRAMATICALLY RAISED THE POP
OVER THE MTNS TO DEAL WITH THE CONVECTIVE TREND. EAST OF THE MTNS
THE PICTURE IS NOT AS CLEAR AS THE AIR MASS IS NOT AS FAVORABLE
OWING TO DEWPT IN THE LOW/MID 60S...SO THERE MIGHT BE SOME STRUGGLE
TO MAINTAIN IT OFF THE BLUE RIDGE. THE NAM AND 4KM WRF SUGGEST THAT
LOW LEVEL CONVERGENCE IN THE WNW FLOW WILL MAINTAIN THE CONVECTION
DOWN ACROSS THE I-26/I-385 CORRIDOR...SO HAVE INCREASED THE POP
THERE AS WELL. OVER TOWARD I-77...NOT SO MUCH. SOME STRONGER MID
LEVEL FLOW WILL SUPPORT A WIND DAMAGE THREAT INTO THE EVENING. TEMP
TRENDS HAVE NOT KEPT UP WITH THE PREVIOUS FCST...SO A HEAT ADVISORY
SEEMS LESS LIKELY FOR THE LATE AFTERNOON.

OVERNIGHT...THE MODELS ARE SUGGESTING THAT ANOTHER MCS WILL DEVELOP
UPSTREAM OVER THE OZARKS OR MID MS VALLEY LATER THIS EVENING...AND
THAT IT WILL MAKE A RUN AT THE MTNS LATE TONIGHT. WILL ALLOW THE POP
TO WANE THIS EVENING AS THE FIRST CONVECTIVE LINE LEAVES...BUT WILL
RETAIN THE CHANCE POP ON THE TN BORDER IN CASE THIS WORKS OUT. MIN
TEMPS WERE KEPT ABOVE GUIDANCE...ESPECIALLY WITH THE POSSIBILITY OF
PLENTY OF CONVECTIVE DEBRIS CLOUDS.

ON TUESDAY...IF THERE ARE NO CONVECTIVE REMNANTS...AN MCV IS A VERY
REAL POSSIBILITY. WE REMAIN UNDER A BROAD UPPER TROF THAT IS
GENERALLY FAVORABLE WITH SOME WEAK UPPER Q CONVERGENCE. ALMOST THE
ENTIRE FCST AREA IS IN THE SLIGHT RISK BECAUSE OF THIS AND THE
STRONGER MID LEVEL FLOW. THE SREF HAS A VERY HIGH POP FOR THE
AFTERNOON SO SOME UPWARD ADJUSTMENT WAS MADE. TEMPS WERE NUDGED
TOWARD A GUIDANCE BLEND.

&&

.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/...
AS OF 2 PM MONDAY...THE SHORT TERM FCST PICKS UP AT 00Z ON WEDNESDAY
WITH THE AXIS OF THE GREAT LAKES H5 TROF ORIENTED N/S JUST TO OUR
WEST. THE MODELS SUGGEST THAT SOME SORT OF WEAK H5 SHORTWAVE WILL BE
MOVING OVER THE FCST AREA AT THE BEGINNING OF THE PERIOD FOLLOWED BY
A SERIES OF ADDITIONAL UPPER SHORTWAVES TRANSLATING OVER THE REGION
LATE WED AND INTO THURS. HEIGHTS BEGIN TO SLOWLY RISE AGAIN TOWARDS
THE END OF THE PERIOD AS THE WEST CONUS H5 RIDGE MODERATELY
BUILDS. LATE TUES AND EARLY WEDNESDAY...THE LOW LVL FRONTAL
BOUNDARY SHOULD MOVE SE OF THE CWFA AND USHER IN DRIER NWLY FLOW.
GREATEST CHANCE FOR ANY WIDESPREAD CONVECTION WILL BE DURING THE
FIRST 6 HRS OR SO OF THE PERIOD WITH THE BOUNDARY LAYER PW VALUES
DROPPING FAIRLY QUICKLY AFTER 06Z. EXPECT MOSTLY DRY CONDITIONS WITH
MODERATE DOWNSLOPE FLOW AND JUST A SLIGHT CHANCE POP OVER THE
NORTHERN AND CENTRAL NC MTS DURING THE DAY/EVENING. HIGHS WILL BE A
BIT COOLER BUT STILL PROGGED TO REACH THE MID 90S OVER THE LOWER
ELEVATIONS. ON THURS...THE CENTER OF THE SFC HIGH WILL SLIDE JUST TO
OUR NORTH PROVIDING MORE NORTHERLY LOW LVL FLOW AND BRINGING TEMPS
DOWN A FEW MORE DEGREES TO THE LOWER 90S OVER THE PIEDMONT AND
FOOTHILLS. I KEPT A SLIGHT CHANCE OVER THE WESTERN NC MTS AND FAR NE
GA ZONES FROM ABOUT NOON TO 7PM...HOWEVER PROFILES MAY BE TOO DRY TO
SEE ANY PRECIP.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
AS OF 3 PM MONDAY...A BLEND OF THE ECMWF AND GFS WILL BE USED FOR
THE EXTENDED RANGE FORECAST. A LONG WAVE TROF WILL REMAIN EAST OF
THE MISSISSIPPI RIVER VALLEY THROUGH THE LATE WEEK AND WEEKEND. ON
FRIDAY...MID LEVEL HEIGHTS REMAIN SLIGHTLY NORTHWEST WITH WEAK HIGH
PRESSURE CENTERED OVER THE MID ATLANTIC STATES. BASED ON THE LLVL
THICKNESSES AND DECENT INSOLATION IT APPEARS THAT HIGH TEMPERATURES
WILL REMAIN A FEW DEGREES ABOVE NORMAL. FORECAST SOUNDINGS INDICATE
THAT GREATEST POTENTIAL INSTABILITY WILL OCCUR ACROSS THE UPPER
SAVANNAH RIVER VALLEY AND THE UPSTATE OF SC. I WILL ADVERTISE SCHC
POPS FOR AFTERNOON AND EVENING TSRA.

SATURDAY AND SUNDAY...A NOTABLE S/W WILL DIVE ACROSS THE MID WEST
AND OHIO RIVER VALLEY...POSSIBLY MOVING ACROSS THE REGION ON SUNDAY.
FORECAST SOUNDINGS INDICATE WIDESPREAD WEAK INSTABILITY EACH
AFTERNOON AND EVENING. BASED ON THE SIGNIFICANT S/W...INCREASING
WIND FIELDS...AND WIDESPREAD INSTABILITY IT APPEARS THAT 30 TO 50
POPS ARE JUSTIFIED EACH DAY. ON MONDAY...MID LEVEL TROF AXIS APPEARS
TO AMPLIFY ACROSS THE REGION WITH SOME WRAP AROUND MOISTURE. BASED
ON NATIONAL GUIDANCE AND MID LEVEL PATTERN IT APPEARS THAT AT LEAST
SCHC POPS ARE REASONABLE DURING THE AFTERNOON AND EVENING.
TEMPERATURES SHOULD RANGE AROUND NORMAL THROUGH THE WEEKEND INTO
MONDAY.

&&

.AVIATION /19Z MONDAY THROUGH SATURDAY/...
AT KCLT...VFR CONDITIONS THROUGH THE PERIOD. FOR THIS AFTERNOON AND
EVENING...MAINLY A WIND FCST. TCLT RADAR WIND PROFILE SHOWS NW IN
THE BOUNDARY LAYER SO EXPECT NW WINDS TO CONTINUE AT THE SFC FOR AT
LEAST THE REMAINDER OF THE DAYLIGHT HOURS. FOR CLOUDS...ONLY A FEW
HIGH-BASED STRATOCU TO DEAL WITH...ALTHO THERE IS A VERY REMOTE
POSSIBILITY OF A SHOWER LATE THIS AFTERNOON. AM WATCHING CONVECTION
MOVING ACROSS ERN TN WITH SOME INTEREST. WESTERLY WIND ALOFT IS LESS
FAVORABLE FOR IT REACHING THE PIEDMONT. THERE IS A LOW CHANCE OF ANY
RESTRICTIONS IN THE MORNING. SOME CONVECTIVE DEBRIS CLOUDS SHOULD
ROLL IN AFTER SUNRISE TUESDAY. THINK ANY DEEPER CONVECTION WILL
PROBABLY HOLD OFF UNTIL AFTER THE END OF THE TAF PERIOD.

ELSEWHERE...GENERALLY A WESTERLY COMPONENT TO THE WIND THIS
AFTERNOON...FUNNELLED BY THE TERRAIN. CONVECTION OVER ERN TN WILL BE
WATCHED FOR IMPACT AT KAVL AND OTHER TAF SITES AND WILL AMEND
ACCORDINGLY. THE BEST CHANCE MIGHT BE AROUND KGSP AROUND 21Z AS
CONVERGENCE IN WNW FLOW MAY AID THE REDEVELOPMENT OF THE
CONVECTION...AS SHOWN BY THE NAM AND WRF-NMM MODELS. FOR NOW...WILL
LEAVE IT OUT. LATER TONIGHT A MORE ORGANIZED AREA OF SHRA/TSTMS MAY
MOVE INTO THE MTNS. SOME FOG IS POSSIBLE AT KAVL AROUND SUNRISE.
THERE SHOULD BE MORE CONVECTIVE DEBRIS CLOUDS AFTER SUNRISE TUESDAY.

OUTLOOK...MOISTURE WILL GRADUALLY DIMINISH EARLY NEXT WEEK IN
PERSISTENT WESTERLY FLOW. STILL EXPECT ISOLD-SCT SHWRS/TSTMS THRU
THE PERIOD.

AN EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLE SHOWING THE
PERCENTAGE OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED ISSUANCE
CATEGORY IS AVAILABLE AT FOLLOWING LINK (USE LOWER CASE)...

WWW.WEATHER.GOV/GSP/AVIATION/TABLES.HTM

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.

&&

SYNOPSIS...JPT
NEAR TERM...PM
SHORT TERM...JPT
LONG TERM...NED
AVIATION...PM

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
554 AM EDT MON AUG 8 2011

GAZ018-026-028-029-NCZ035>037-056-057-068>072-082-502-504-506-508-
510-SCZ004>014-019-091000-
STEPHENS-FRANKLIN-HART-ELBERT-ALEXANDER-IREDELL-DAVIE-CATAWBA-ROWAN-
CLEVELAND-LINCOLN-GASTON-MECKLENBURG-CABARRUS-UNION NC-
GREATER CALDWELL-GREATER BURKE-EASTERN MCDOWELL-GREATER RUTHERFORD-
EASTERN POLK-GREATER OCONEE-GREATER PICKENS-GREATER GREENVILLE-
SPARTANBURG-CHEROKEE-YORK-ANDERSON-ABBEVILLE-LAURENS-UNION SC-
CHESTER-GREENWOOD-
554 AM EDT MON AUG 8 2011

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

.DAY ONE...TODAY AND TONIGHT.

AS AFTERNOON HEAT INDEX VALUES REACH INTO THE LOWER 100S...
ISOLATED THUNDERSTORMS ARE EXPECTED TO DEVELOP. IT IS NOT OUT OF
THE QUESTION THAT A COUPLE OF THESE STORMS WILL PRODUCE DAMAGING
WIND GUSTS OR HAIL TO THE SIZE OF QUARTERS.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY.

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

NONE.

GAZ010-017-NCZ033-048>053-058-059-062>065-501-503-505-507-509-
SCZ001>003-091000-
RABUN-HABERSHAM-AVERY-MADISON-YANCEY-MITCHELL-SWAIN-HAYWOOD-BUNCOMBE-
GRAHAM-NORTHERN JACKSON-MACON-SOUTHERN JACKSON-TRANSYLVANIA-
HENDERSON-CALDWELL MOUNTAINS-BURKE MOUNTAINS-MCDOWELL MOUNTAINS-
RUTHERFORD MOUNTAINS-POLK MOUNTAINS-OCONEE MOUNTAINS-
PICKENS MOUNTAINS-GREENVILLE MOUNTAINS-
554 AM EDT MON AUG 8 2011

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

.DAY ONE...TODAY AND TONIGHT.

ISOLATED THUNDERSTORMS ARE EXPECTED TO DEVELOP TODAY. IT IS NOT OUT OF
THE QUESTION THAT A COUPLE OF THESE STORMS WILL PRODUCE DAMAGING
WIND GUSTS OR HAIL TO THE SIZE OF QUARTERS.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY.

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

NONE.

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
915 AM EDT MON AUG 08 2011

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0708 PM     TSTM WND DMG     1 E BOILING SPRINGS SC  35.04N 81.96W
08/07/2011                   SPARTANBURG        SC   911 CALL CENTER

            POWERLINES DOWN OFF OF KNOLLWOOD COURT. TIME ESTIMATED
            FROM RADAR.

&&

ZHARGROV

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
1038 AM EDT MON AUG 08 2011

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0728 PM     HAIL             2 NE SPARTANBURG        34.97N 81.90W
08/07/2011  E1.75 INCH       SPARTANBURG        SC   POST OFFICE

            CUSTOMER AT DRAYTON POST OFFICE REPORTED GOLF BALL SIZE
            HAIL THAT DAMAGED HER YARD. TIME ESTIMATED FROM RADAR.

&&

ZHARGROV

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
208 PM EDT MON AUG 8 2011

NCZ051-058-081845-
GRAHAM-SWAIN-
208 PM EDT MON AUG 8 2011

...STRONG THUNDERSTORMS WILL AFFECT GRAHAM AND WESTERN SWAIN COUNTIES
THROUGH 245 PM EDT...

AT 204 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
STRONG THUNDERSTORMS ALONG A LINE EXTENDING FROM TALASSEE TO 6 MILES
SOUTHEAST OF CITICO TO 6 MILES WEST OF MURPHY...MOVING EAST AT 25
MPH.

THESE STORMS WILL BE NEAR...
  TAPOCO...
  SANTEETLAH LAKE...
  FONTANA VILLAGE...
  ROBBINSVILLE...
  FONTANA LAKE...

PEOPLE IN GRAHAM AND WESTERN SWAIN COUNTIES...INCLUDING THE FOLLOWING
LOCATIONS...

TAPOCO...SANTEETLAH LAKE...FONTANA VILLAGE...ROBBINSVILLE...FONTANA
LAKE AND STECOAH...

SHOULD MONITOR THE WEATHER SITUATION CLOSELY. LISTEN FOR POSSIBLE
WARNINGS AND BE PREPARED TO TAKE APPROPRIATE ACTION SHOULD SEVERE
WEATHER THREATEN.

MOTHBALL SIZE HAIL...AND WIND GUSTS UP TO 50 MPH ARE EXPECTED WITH
THESE STORMS.

FREQUENT LIGHTNING IS OCCURRING WITH THIS STORM. IF OUTDOORS...STAY
AWAY FROM ISOLATED HIGH OBJECTS SUCH AS TREES. MOVE INDOORS IF
POSSIBLE. WHEN INDOORS...STAY AWAY FROM WINDOWS AND DOORS AND AVOID
USING TELEPHONES UNLESS IT IS AN EMERGENCY. TRY TO UNPLUG UNNECESSARY
ELECTRICAL APPLIANCES BEFORE THE THUNDERSTORM APPROACHES.

LAT...LON 3537 8401 3541 8403 3548 8392 3553 8388
      3553 8383 3557 8377 3558 8360 3557 8353
      3526 8369 3524 8373 3525 8384 3521 8396
      3523 8401 3531 8404 3536 8404

NED

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
313 PM EDT MON AUG 8 2011

NCZ052-059-062-063-082000-
HAYWOOD-MACON-NORTHERN JACKSON-SOUTHERN JACKSON-
313 PM EDT MON AUG 8 2011

...STRONG THUNDERSTORMS WILL AFFECT CENTRAL HAYWOOD...EASTERN MACON
AND JACKSON COUNTIES THROUGH 400 PM EDT...

AT 311 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
STRONG THUNDERSTORMS ALONG A LINE EXTENDING FROM NEWFOUND GAP TO 5
MILES SOUTH OF ALARKA TO 4 MILES NORTHEAST OF HIAWASSEE...MOVING EAST
AT 30 MPH.

THESE STORMS WILL BE AFFECT LOCATIONS NEAR...
  SYLVA...
  CULLOWHEE...
  THORPE RESERVOIR...
  HIGHLANDS...

WIND GUSTS OF 40 TO 50 MPH ARE EXPECTED WITH THESE STORMS.

LAT...LON 3533 8337 3533 8334 3535 8333 3540 8334
      3541 8336 3546 8336 3547 8332 3553 8323
      3551 8318 3555 8316 3560 8299 3510 8301
      3506 8305 3502 8301 3500 8340

LANE