Special Weather Statement, NWS Greenville-Spartanburg, SC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
252 PM EDT THU AUG 9 2012

.SYNOPSIS...
A STRONG LOW PRESSURE SYSTEM WILL OVER THE GREAT LAKES WILL PUSH A
COLD FRONT ACROSS THE REGION FROM THE WEST LATE FRIDAY. THE FRONT
WILL PUSH SOUTH OF THE AREA ON SUNDAY. MEANWHILE ANOTHER FRONT WILL
APPROACH THE AREA BY MID WEEK.

&&

.NEAR TERM /THROUGH FRIDAY/...
AS OF 230 PM...WATER VAPOR IMAGERY SHOWS A DIGGING UPSTREAM TROUGH
MOVING THROUGH TN THIS AFTN. SEVERAL CONVECTIVE CLUSTERS DEVELOPED
ACROSS CNTRL/ERN TN...NE AL...AND NW GA AHEAD OF THIS FEATURE IN THE
MODERATELY UNSTABLE AIRMASS. HEATING AND CONVECTION OVER OUR
FORECAST AREA WERE LIMITED EARLY BY CONSIDERABLE HIGH CLOUDS...BUT
QUICKLY REBOUNDING SFC BASED CAPES AT OR ABOVE 3000 J/KG...COMBINED
WITH SRLY UPSLOPE FLOW INTO THE HIGH TERRAIN...AND THE ARRIVAL OF
THE CONVECTION FROM THE SW WARRANT CATEGORICAL POPS IN SW
SECTIONS...RANGING DOWN TO CHC IN THE NW NC PIEDMONT INTO THE
EVENING HOURS. ENTERTAINED THE IDEA OF A SHORT FUSE FLASH FLOOD
WATCH FOR THE SW MTNS...BUT UPSTREAM RATES NEAR THE GA/AL BORDER
APPEAR TO BE TAPERING OFF SOME. THE MID LEVEL DRY PUNCH IS GRADUALLY
MOISTENING UP TO RELAX THE THETA E LAPSE...BUT PLENTY OF DCAPE/CAPE
IS AVAILABLE OVER THE SE HALF FOR A CONTINUED MICROBURST AND
MARGINAL LARGE HAIL THREAT.

THE SHORTWAVE WILL DAMPEN AS IT MOVES INTO THE REGION TONIGHT...BUT
IT MAY STILL PROVIDE ENOUGH FORCING TO KEEP SCT TSRA GOING THIS
EVENING...WITH MAINLY SCT SHRA OVERNIGHT. THE MAIN UPPER TROUGH AXIS
EXTENDING SWD FROM GREAT LAKES LOW PRES WILL THEN SHARPEN UP WEST OF
THE MTNS THROUGH FRI. 850 MB FLOW SHOULD STRENGTHEN SOMEWHAT AHEAD
OF THIS FEATURE...BUT ALSO VEER A BIT TO CAP LOW LEVEL BULK SHEAR.
THE BEST DEEP LAYER Q VECTOR CONVERGENCE WILL WORK BACK INTO THE
AREA FROM THE WEST TOMORROW AFTN...WITH THE SFC COLD FRONT
APPROACHING FROM THE NW JUST REACHING THE MTNS TOWARD THE END OF THE
PERIOD. THE MODEST INCREASE IN BULK SHEAR AND LESS THAN IMPRESSIVE
LAPSE RATES ALOFT MAKE THE SEVERE THREAT A BIT UNCERTAIN.
HOWEVER...SUCH A WELL FORCED SYSTEM THIS TIME OF YEAR SHOULD
CERTAINTY PRODUCE SOME SEVERE TSTMS...SO THE SLIGHT RISK APPEARS
WELL PLACED FOR DAY 2.

&&

.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
AS OF 215 PM THURSDAY...A COLD FRONT SHOULD BE ENTERING THE AREA
FROM THE NW AT 00Z SAT. CURRENT INDICATIONS ARE THAT THE FRONT
WILL BE SLOW TO CLEAR THE AREA AS THE UPPER TROUGH AXIS LAGS TO THE
WEST. THIS WILL KEEP A SOLID THREAT OF AT LEAST SCATTERED TO NUMEROUS
SHOWERS/THUNDERSTORMS GOING OVER THE SE PORTION OF THE AREA FRI
NIGHT WHICH WILL THEN CONTINUE INTO SAT. THE 12Z NAM IS MUCH QUICKER
IN MOVING THE DEEP MOISTURE/PRECIP EASTWARD ON SAT. THE GFS AND GEM
ARE CONSIDERABLY SLOWER/WETTER AS THEY DEVELOP A WEAK FRONTAL WAVE
ON SAT. IN SITUATIONS LIKE THIS...THE SREF USUALLY RESOLVES TO SOME
EXTENT THE DISCONTINUITIES IN THE OPERATIONAL RUNS. HENCE...HAVE
LEANED ON THE SREF FOR POPS/QPF FOR FRI NIGHT AND SAT. THIS YIELDS
LIKELY POPS OVER THE SE UPSTATE INTO THE SOUTHERN NC PIEDMONT...
WITH SCATTERED TYPE POPS WESTWARD TO ABOUT GREENVILLE AND NE/SW FROM
THERE. UPPER TROUGH AXIS FINALLY MOVES THROUGH SAT NIGHT WHICH
SHOULD SWEEP THE REMAINING MOISTURE EASTWARD. SURFACE HIGH PRESSURE
WILL BUILD OVER THE REGION ON SUN AND PRODUCE CONSIDERABLE SUNSHINE
WITH NEAR CLIMO TEMPS...AND CONFORTABLE RH IN THE AFTERNOON.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AS OF 145 PM THURSDAY...UPPER FLOW SHOULD BEGIN ESSENTIALLY ZONAL
OVER THE REGION EARLY NEXT WEAK AND THEN GENERALLY REVERT BACK TO A
TROUGH IN THE EAST AND A RIDGE TO THE WEST. HOWEVER...THE
OPERATIONAL MODELS LOOK WILDLY OUT OF PHASE BY THE END OF NEXT
WEEK..SO THIS THIS COULD CHANGE. FOR THE SENSIBLE WEATHER...WILL GENERALLY
FOLLOW THE HPC GUIDANCE WHICH USED A BLEND OF THE ECM/GFS/UK MET
EARLY ON...AND THEN A GFS/ECM BLEND LATE IN THE PERIOD. THIS BREAKS
DOWN TO SURFACE HIGH PRESSURE MOVING EAST OF THE AREA ON MON BUT
STILL CONTROLLING THE WEATHER. HENCE...ONLY SOME VERY LOW END POPS
OVER THE MOUNTAINS MON AFTERNOON AND TEMPS A LITTLE ABOVE AVERAGE.
LOOKS LIKE A WEAK COLD FRONT SHOULD MOVE ACROSS THE AREA TUE INTO
TUE NIGHT. THEREFORE...WILL RAMP UP POPS INTO THE CHANCE RANGE FOR
THAT. FOR WED AND THU...WEAK HIGH PRESSURE SHOULD BE OVER THE AREA
WITH GENERALLY DRY CONDITIONS AND TEMPS NEAR CLIMO EXPECTED. CAN'T RULE OUT
SOME WIDELY SCT MOUNTAIN CONVECTION...BUT LOW POPS FOR NOW.

&&

.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
AT KCLT...IN SPITE OF ALL THE HIGH LEVEL CLOUDINESS TODAY...SFC
BASED CAPE VALUES AROUND KCLT HAVE RISEN ABOVE 3000 J/KG ON THE
LATEST LAPS ANALYSIS. CONVECTIVE COVERAGE IS INCREASING FROM THE
SW...AND DEVELOPING OUTFLOWS SHOULD IMPROVE PIEDMONT COVERAGE
THROUGH 21Z. WILL FEATURE TEMPO TSRA FROM 21Z TO 01Z...FOLLOWED BY
VCSH FOR A GOOD CHUNK OF THE OVERNIGHT AS A SHORTWAVE PASSES
OVERHEAD. THE ABUNDANT LOW LEVEL MOISTURE AND SW UPGLIDE FLOW SHOULD
YIELD MVFR CIGS TOWARD DAYBREAK IN LINE WITH THE LATEST MET
GUIDANCE. WILL BRING VCSH BACK MID MORNING...WITH PROB TSRA 16Z TO
18Z WITH THE ARRIVAL OF ADDITIONAL UPPER SUPPORT FROM THE WEST BY
MIDDAY FRI.

ELSEWHERE...AN AREA OF SOLID CONVECTION HAS DEVELOPED WEST OF THE
APPALACHIANS THIS AFTERNOON AHEAD OF A SHORTWAVE. ADDITIONAL MTN
RIDGE TOP CONVECTION IS DEVELOPING IN LIGHT SRLY UPSLOPE FLOW...AND
KAVL SHOULD SEE TSRA FIRST BY AROUND 19Z. THE FOOTHILL TAF SITES
WILL EXPERIENCE TEMPO TSRA FROM THE SW...WITH A KAND ARRIVAL AROUND
20Z...AND KGMU TO KGSP BY 21Z. KHKY COVERAGE REMAINS A BIT MORE IN
DOUBT GIVEN THE WEAK FORCING TO THE N AND RELATIVE INSTABILITY
MINIMA NEARBY. WILL CONTINUE TO RIDE ON AN AFTN VCTS THERE. THE
MOIST SRLY FLOW AT LOW LEVELS HAS ALSO PRODUCED SOME MVFR CIGS IN
THE UPSTATE...BUT THESE SHOULD CONTINUE TO LIFT AND SCATTER WITH
MIXING UNTIL THE TSRA ARRIVE. A RETURN TO MVFR CIGS IS LIKELY
THROUGHOUT OVERNIGHT...WITH IFR CIGS EXPECTED IN THE FRENCH BROAD
VALLEY. MOISTURE CONTINUES TO DEEPEN INTO FRI WITH THE APPROACH OF A
MORE PROMINENT UPPER TROUGH AND UPSTREAM COLD FRONT.

OUTLOOK...A COLD FRONT WILL SLOWLY CROSS THE AREA FRI NIGHT THROUGH
SAT...WITH DRIER HIGH PRES BUILDING IN FROM THE W THE LATTER HALF OF
THE WEEKEND. WEAK HIGH PRESSURE WILL LINGER THROUGH EARLY NEXT WEEK.

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...PAT
NEAR TERM...HG
SHORT TERM...LG
LONG TERM...LG
AVIATION...HG

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
243 PM EDT THU AUG 9 2012

GAZ010-017-018-026-028-029-NCZ033-035>037-048>053-056>059-062>065-
068>072-082-501>510-SCZ001>014-019-101845-
RABUN-HABERSHAM-STEPHENS-FRANKLIN-HART-ELBERT-AVERY-ALEXANDER-
IREDELL-DAVIE-MADISON-YANCEY-MITCHELL-SWAIN-HAYWOOD-BUNCOMBE-CATAWBA-
ROWAN-GRAHAM-NORTHERN JACKSON-MACON-SOUTHERN JACKSON-TRANSYLVANIA-
HENDERSON-CLEVELAND-LINCOLN-GASTON-MECKLENBURG-CABARRUS-UNION NC-
CALDWELL MOUNTAINS-GREATER CALDWELL-BURKE MOUNTAINS-GREATER BURKE-
MCDOWELL MOUNTAINS-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-ABBEVILLE-LAURENS-UNION SC-CHESTER-GREENWOOD-
243 PM EDT THU AUG 9 2012

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

.DAY ONE...THIS AFTERNOON AND TONIGHT.

SHOWERS AND THUNDERSTORMS WILL CONTINUE TO DEVELOP ACROSS THE
WESTERN CAROLINAS AND NORTHEAST GEORGIA FROM THE SOUTHWEST
THROUGH THE LATE AFTERNOON AND EVENING HOURS. SOME OF THESE
THUNDERSTORMS WILL BE CAPABLE OF PRODUCING LOCALLY DAMAGING WIND
GUSTS AND LARGE HAIL...ESPECIALLY SOUTHEAST OF THE INTERSTATE 85
CORRIDOR. THE THUNDERSTORMS WILL ALSO PRODUCE TORRENTIAL RAINFALL
AT RATES OF 1 TO 2 INCHES PER HOUR. EXCESSIVE RAINFALL COULD
RESULT IN LOCATIONS REPEATEDLY AFFECTED BY THUNDERSTORMS. ISOLATED
FLOODING IS POSSIBLE...ESPECIALLY OVER THE CENTRAL AND SOUTHERN
MOUNTAINS OF WESTERN NORTH CAROLINA.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY.

A STRONG COLD FRONT AND UPPER LEVEL DISTURBANCE WILL APPROACH THE
REGION ON FRIDAY. THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS
ASSOCIATED WITH THE FRONT. DAMAGING WIND GUSTS WILL BE THE
PRIMARY THREAT...ESPECIALLY OVER FOOTHILL AND PIEDMONT LOCATIONS
FRIDAY AFTERNOON AND EVENING.

.SPOTTER INFORMATION STATEMENT...

SKYWARN SPOTTERS ARE REQUESTED TO FORWARD ANY REPORTS OF LARGE
HAIL...DAMAGING WINDS...TORNADOES OR FLASH FLOODING TO OUR OFFICE.

GERAPETRITIS

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
641 PM EDT THU AUG 9 2012

NCZ068-503-504-506-508-092315-
BURKE MOUNTAINS-CLEVELAND-EASTERN MCDOWELL-GREATER BURKE-GREATER
RUTHERFORD-
641 PM EDT THU AUG 9 2012

...STRONG THUNDERSTORMS WILL AFFECT BURKE...NORTHEASTERN
RUTHERFORD...NORTHWESTERN CLEVELAND AND SOUTHEASTERN MCDOWELL
COUNTIES THROUGH 715 PM EDT...

AT 639 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
STRONG THUNDERSTORMS ALONG A LINE EXTENDING FROM 3 MILES NORTHWEST OF
DYSARTSVILLE TO 3 MILES NORTHWEST OF CASAR...MOVING NORTHEAST AT 40
MPH.

PEOPLE IN BURKE...NORTHEASTERN RUTHERFORD...NORTHWESTERN CLEVELAND
AND SOUTHEASTERN MCDOWELL COUNTIES...INCLUDING THE FOLLOWING
LOCATIONS...

DYSARTSVILLE...CASAR...MORGANTON...VALDESE...RUTHERFORD COLLEGE...
CONNELLY SPRINGS AND ICARD...

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

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

FREQUENT LIGHTNING IS OCCURRING WITH THIS STORM. IF OUTDOORS...TRY TO
GET INDOORS OR INTO A HARD TOPPED VEHICLE. OTHERWISE...STAY AWAY FROM
OPEN AREAS AND ISOLATED HIGH OBJECTS SUCH AS TREES. WHEN INDOORS...
STAY AWAY FROM WINDOWS AND DOORS AND AVOID USING WIRED ELECTRONIC
DEVICES. TRY TO UNPLUG UNNECESSARY APPLIANCES BEFORE THE STORM
APPROACHES.

LAT...LON 3594 8180 3578 8156 3578 8154 3576 8138
      3562 8149 3557 8153 3556 8153 3545 8161
      3557 8202

NED

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
650 PM EDT THU AUG 09 2012

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

0635 PM     TSTM WND GST     5 NNE RUTHERFORDTON     35.43N 81.94W
08/09/2012  M54 MPH          RUTHERFORD         NC   AWOS

&&

MCAVOY

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
656 PM EDT THU AUG 09 2012

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

0540 PM     TSTM WND DMG     LAURENS                 34.50N 82.03W
08/09/2012                   LAURENS            SC   911 CALL CENTER

            A TREE FELL ON A POWER LINE ON HILLTOP ROAD.

&&

JOH

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
720 PM EDT THU AUG 09 2012

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

0619 PM     TSTM WND DMG     FOREST CITY             35.34N 81.87W
08/09/2012                   RUTHERFORD         NC   911 CALL CENTER

            TREES DOWN THROUGHOUT THE AREA

&&

LG

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
724 PM EDT THU AUG 09 2012

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

0659 PM     TSTM WND DMG     MORGANTON               35.74N 81.70W
08/09/2012                   BURKE              NC   TRAINED SPOTTER

            TREES AND POWER LINES DOWN ON SPAINHOUR RD AND ALONG 181.

&&

LG

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
732 PM EDT THU AUG 9 2012

SCZ007-008-013-100000-
CHEROKEE-SPARTANBURG-UNION-
732 PM EDT THU AUG 9 2012

...A STRONG THUNDERSTORM WILL AFFECT EASTERN SPARTANBURG...
NORTHWESTERN UNION AND SOUTHERN CHEROKEE COUNTIES THROUGH 800 PM
EDT...

AT 729 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM 4 MILES WEST OF JONESVILLE...OR 10 MILES
NORTHWEST OF UNION...MOVING NORTH AT 20 MPH.

THIS STORM WILL IMPACT LOCATIONS NEAR...
  JONESVILLE...
  PACOLET...
  THICKETTY...

WIND GUSTS UP TO 40 MPH...AND TORRENTIAL RAIN ARE EXPECTED WITH THIS
STORM.

LAT...LON 3512 8177 3505 8151 3471 8159 3476 8200

NED