Severe Thunderstorm Warning 331, NWS Greenville-Spartanburg, SC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
1108 AM EDT WED AUG 5 2009

.SYNOPSIS...
A COLD FRONT WILL APPROACH FROM THE NORTHWEST TONIGHT...MOVE JUST
SOUTH OF OUR AREA THURSDAY...THEN MOVE BACK NORTH AS A WARM FRONT
THURSDAY NIGHT AND FRIDAY.  A STRONG RIDGE OF HIGH PRESSURE WILL
DEVELOP ACROSS THE SOUTHEAST STATES FRIDAY THROUGH MONDAY...THOUGH
WITH CONTINUED MOISTURE UNDER THE RIDGE. THE RIDGE WILL BREAK DOWN
NEXT TUESDAY AS ANOTHER COLD FRONT APPROACHES FROM THE NORTHWEST.

&&

.NEAR TERM /THROUGH TONIGHT/...
AT 15Z...SKY COVER ACROSS THE CWA WAS SUNNY TO MOSTLY SUNNY.
RECENT SATELLITE IMAGES INDICATE THAT AN OLD OUTFLOW BOUNDARY ACROSS
NRN GA AND EXTREME WESTERN NC AT 15Z. IN ADDITION...A POTENT S/W
WAS LOCATED ON WATER VAPOR OVER EASTERN TN. THE OUTFLOW BOUNDARY
SHOULD CONTINUE TO SLOWLY SLIDE EAST THROUGH THE EARLY AFTERNOON.
THE VORT MAX IS EXPECTED TO CROSS THE NRN MTNS EARLY THIS AFTERNOON
AND CONTINUE EAST ACROSS THE FOOTHILLS AND PIEDMONT LATE THIS
AFTERNOON. AHEAD OF THESE FEATURES...TEMPERATURES WILL PEAK A DEGREE
OR TWO ABOVE NORMAL WITH DEWPOINTS IN THE MID 60S. CAPE VALUES
ACROSS THE CWA SHOULD BECOME MARGINALLY UNSTABLE WITH DCAPE VALUES
BETWEEN 600-1000 J/KG. BASED ON TIMING OF THE S/W AND
INSTABILITY...I WILL FORECAST SHRA/TSRA TO DEVELOP ACROSS THE MTNS
BETWEEN 17-20Z. STEERING FLOW SHOULD CARRY THE CONVECTION
EAST...POSSIBLY ORGANIZING ALONG A COLD POOL OVER THE NC FOOTHILLS.
A BAND OF TSRA MAY SWEEP ACROSS THE REMAINDER OF THE FOOTHILLS AND
NC PIEDMONT BETWEEN 20-3Z. ELSEWHERE...SCT COVERAGE OF SHRA/TSRA
SHOULD DEVELOP DURING THE AFTERNOON AND REMAIN UNTIL MID TO LATE
EVENING. THE MAIN THREAT ASSOCIATED WITH TODAY/S STORMS WILL BE SVR
WIND GUSTS...A FEW STRONGER STORM CLUSTERS COULD PRODUCE LARGE HAIL.
I WILL INCREASE POPS...ESPECIALLY ACROSS THE NC ZONES. CURRENT
WORDING IN THE HWO HIGHLIGHTS THE THREATS WELL.

&&

.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 230 AM WEDNESDAY...A DIFFLUENT UPPER FLOW PATTERN WILL
CONTINUE ACROSS THE AREA THU/THU NIGHT...AS THE ERN UPPER TROUGH
AXIS MOVES INTO NEW ENGLAND AND RIDGING PERSISTS OVER THE SOUTHERN
PLAINS. DEEP LAYER DRYING IS INDICATED EARLY THU JUST BEHIND THE
WAVE DEPARTING TOWARD THE COAST. DESPITE THE FAVORABLE MCS TRACK
STEERING FLOW FROM THE UPPER MIDWEST TO THE SOUTHERN
APPALACHIANS...THE MODELS ARE NOT TOO KEEN ON DEVELOPING ANY
SIGNIFICANT CONVECTIVE SYSTEM THU/THU NIGHT. PLUS...A NW
DOWNSLOPE FLOW WILL HELP TO KEEP CONVECTION AT BAY EAST OF THE HIGH
TERRAIN IN THE DRIER AIR. POPS HAVE THUS BEEN LOWERED TO SLIGHT
CHANCE IN ALL BUT THE MOST UNSTABLE SRN PIEDMONT SECTIONS.

A WEAK COLD FRONT IS EXPECTED TO SETTLE SOUTHWARD ACROSS THE
FORECAST AREA THURSDAY NIGHT...WITH SFC HIGH PRES BUILDING OVER TO
THE NORTH THROUGH FRIDAY. MEANWHILE...RIDGING ALOFT WILL BUILD
EASTWARD OVER THE DEEP SOUTH...PUSHING THE MCS TRACK FARTHER TO THE
NORTH. THE BEST CHANCE FOR ANY FORCING FRI WILL PROBABLY BE
ASSOCIATED WITH A DEVELOPING LOW LEVEL SOUTHEASTERLY UPSLOPE FLOW
LATE IN THE DAY. TEMPERATURES WILL BE NEAR NORMAL THROUGH THE
PERIOD...WITH LOW LEVEL MOISTURE STEADILY REBOUNDING THROUGH FRI
NIGHT.

&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 230 AM WEDNESDAY...STRONG RIDGING WILL DEVELOP OVER THE
SOUTHEAST SATURDAY THROUGH TUESDAY. SOUTHERLY 850 MB FLOW WILL
IMPROVE THE UPSLOPE COMPONENT OVER THE AREA SATURDAY...AS ATLANTIC
AND GULF MOISTURE CONTINUE TO MOISTEN THE BOUNDARY LAYER AND PRODUCE
BETTER DIURNAL CONVECTIVE COVERAGE DURING THE AFTN AND EVENING
HOURS. ISOLATED TO SCATTERED CONVECTION WILL THEN CONTINUE UNDER THE
RIDGE SUN THROUGH MON...SUPPRESSED ONLY SLIGHTLY BY SOME DEGREE OF
WEAK SUBSIDENCE CAPPING ALOFT. NRN TIER ENERGY RIDING OVER THE RIDGE
SHOULD HAVE LITTLE IMPACT ON THE FORECAST AREA...UNTIL A GRADUAL
BREAKDOWN IN THE RIDGE DEVELOPS ON TUESDAY. CONDITIONS WILL REMAIN
HOT AND HUMID THROUGH THE PERIOD...THOUGH A BIT COOLER ON TUESDAY
WITH FALLING HEIGHTS.

&&

.AVIATION /15Z WEDNESDAY THROUGH SUNDAY/...
LIGHT WINDS AND VFR CONDITIONS AT ALL THE TERMINAL LOCATIONS TO
START THE TAF PERIOD. TSTMS ARE EXPECTED TO DEVELOP ACRS THE MTNS
TOWARD MIDDAY...PERHAPS AFFECTING KAVL AS SOON AS EARLY AFTERNOON.
ELSEWHERE...SW WINDS TO INCREASE 6-8 KTS AS VFR LVL CU DEVELOPS.
SCATTERED TSTMS ARE EXPECTED TO DEVELOP OFF THE HIGHER TERRAIN
AND SPREAD INTO THE PIEDMONT INTO EARLY EVENING. A CB MENTION
WILL BE CARRIED AT ALL PIEDMONT TERMINALS TO COVER THREAT.
STATISTICAL GUIDANCE IN GOOD AGREEMENT ACRS THE BOARD IN DEVELOPING
VSBY RESTRICTIONS OVERNIGHT AND WILL INTRODUCE MVFR AT ALL
LOCATIONS.

AT KCLT...LIGHT/VARIABLE WINDS WITH HIGH LVL CLOUDS TO GIVE WAY
TO SSW WINDS ABT 8-10 KTS BY MIDDAY WITH DEVELOPING VFR LVL CU.
SCATTERED TSTM ACTIVITY EXPECTING TO DEVELOP INTO THE PIEDMONT
DURING LATE AFTERNOON AND HAVE INTRODUCED CB MENTION TO COVER
THREAT. MID-LVL DRYING ATOP LINGER MOIST LLVLS WILL GIVE RISE
TO LATE NIGHT BR POTENTIAL.

OUTLOOK...SHOWERS AND THUNDERSTORMS EXPECTED TO DEVELOP EACH
AFTERNOON AND EVENING THROUGH EARLY NEXT WEEK. LIGHT PATCHY EARLY
MORNING FOG OR HAZE COULD OCCUR EACH MORNING...ESPECIALLY WITHIN THE
MTN VALLEYS.

&&

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

&&

SYNOPSIS...HG
NEAR TERM...NED
SHORT TERM...HG
LONG TERM...HG
AVIATION...CSH

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
550 AM EDT WED AUG 5 2009

GAZ010-017-018-026-028-029-NCZ033-035>037-048>053-056>059-062>065-
068>072-082-501>510-SCZ001>014-019-061000-
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-
550 AM EDT WED AUG 5 2009

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

.DAY ONE...TODAY AND TONIGHT.

AN APPROACHING UPPER LEVEL DISTURBANCE WILL ALLOW SHOWERS AND
THUNDERSTORMS TO BECOME NUMEROUS ACROSS THE WESTERN CAROLINAS AND
NORTHEAST GEORGIA THIS AFTERNOON. THUNDERSTORMS MAY BE MORE
SCATTERED IN NATURE ACROSS PIEDMONT SECTIONS. ANY THUNDERSTORMS
THAT DEVELOP WILL HAVE THE POTENTIAL TO PRODUCE LARGE HAIL...WITH
HAILSTONES THE SIZE OF PENNIES OR LARGER...AND DAMAGING WIND GUSTS
IN EXCESS OF 60 MPH. KEEP A CLOSE EYE ON THE WEATHER TODAY IN CASE
ANY SEVERE WEATHER WATCHES OR WARNINGS BECOME NECESSARY.

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

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

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

HG

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
103 PM EDT WED AUG 5 2009

SCZ014-051745-
CHESTER-
103 PM EDT WED AUG 5 2009

...A STRONG THUNDERSTORM WILL AFFECT EASTERN CHESTER COUNTY THROUGH
145 PM EDT...

AT 1255 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM NEAR RICHBURG...OR 9 MILES EAST OF CHESTER...
MOVING EAST AT 15 MPH.

* OTHER LOCATIONS AFFECTED INCLUDE BUT ARE NOT LIMITED TO RICHBURG...
  FORT LAWN AND EDGEMOOR.

SMALL HAIL...AND WIND GUSTS UP TO 50 MPH ARE EXPECTED WITH THIS
STORM.

07

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
107 PM EDT WED AUG 5 2009

NCZ053-065-051800-
BUNCOMBE-HENDERSON-
107 PM EDT WED AUG 5 2009

...A STRONG THUNDERSTORM WILL AFFECT BUNCOMBE AND NORTHERN HENDERSON
COUNTIES THROUGH 200 PM EDT...

AT 107 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM NEAR AVERY CREEK...OR 7 MILES SOUTH OF
ASHEVILLE...MOVING NORTHEAST AT 10 MPH.

* OTHER LOCATIONS AFFECTED INCLUDE BUT ARE NOT LIMITED TO DOWNTOWN
  ASHEVILLE...ASHEVILLE MALL...I-26 AT I-40...FAIRVIEW...SWANNANOA...
  SKYLAND...MILLS RIVER...FLETCHER...BLACK MOUNTAIN...BILTMORE
  FOREST...BENT CREEK...AVERY CREEK AND ASHEVILLE.

SMALL HAIL...AND WIND GUSTS UP TO 50 MPH ARE EXPECTED WITH THIS
STORM.

07

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
121 PM EDT WED AUG 05 2009

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

0110 PM     HAIL             9 SSE ASHEVILLE         35.45N 82.49W
08/05/2009  E0.75 INCH       BUNCOMBE           NC   BROADCAST MEDIA

            WINDS WERE ALSO ESTIMATED TO BE BETWEEN 40 - 45 MPH.

&&

LUKER

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
137 PM EDT WED AUG 5 2009

GAZ010-NCZ062-051830-
MACON-RABUN-
137 PM EDT WED AUG 5 2009

...A STRONG THUNDERSTORM WILL AFFECT RABUN AND SOUTHERN MACON
COUNTIES THROUGH 230 PM EDT...

AT 137 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM 4 MILES NORTHWEST OF LAKE BURTON...OR 11 MILES
WEST OF CLAYTON...MOVING EAST AT 15 MPH.

* OTHER LOCATIONS AFFECTED INCLUDE BUT ARE NOT LIMITED TO LAKE
  BURTON...TIGER...SKY VALLEY...MOUNTAIN CITY...MOCCASIN CREEK STATE
  PARK...DILLARD...CLAYTON...SCALY AND OTTO.

SMALL HAIL...AND WIND GUSTS UP TO 50 MPH ARE EXPECTED WITH THIS
STORM.

07

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
141 PM EDT WED AUG 5 2009

NCZ033-049-050-051845-
AVERY-MITCHELL-YANCEY-
141 PM EDT WED AUG 5 2009

...A STRONG THUNDERSTORM WILL AFFECT NORTHERN MITCHELL...NORTHERN
YANCEY AND WESTERN AVERY COUNTIES THROUGH 245 PM EDT...

AT 141 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM 3 MILES NORTHWEST OF RAMSEYTOWN...OR 7 MILES
SOUTH OF ERWIN...MOVING EAST AT 15 MPH.

* OTHER LOCATIONS AFFECTED INCLUDE BUT ARE NOT LIMITED TO
  RAMSEYTOWN...POPLAR...MINNEAPOLIS...BULADEAN...BANDANA AND
  BAKERSVILLE.

SMALL HAIL...AND WIND GUSTS UP TO 50 MPH ARE EXPECTED WITH THIS
STORM.

07

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
146 PM EDT WED AUG 5 2009

SCZ006-010-011-051845-
ABBEVILLE-ANDERSON-GREATER GREENVILLE-
146 PM EDT WED AUG 5 2009

...A STRONG THUNDERSTORM WILL AFFECT NORTHERN ABBEVILLE...SOUTHERN
ANDERSON AND SOUTHERN GREENVILLE COUNTIES THROUGH 245 PM EDT...

AT 146 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM 3 MILES NORTH OF IVA...OR 12 MILES SOUTH OF
ANDERSON...MOVING NORTHEAST AT 15 MPH.

* OTHER LOCATIONS AFFECTED INCLUDE BUT ARE NOT LIMITED TO SECESSION
  LAKE...BROADWAY LAKE...STARR...PRINCETON...IVA...HONEA PATH...DUE
  WEST...DONALDS...BELTON AND ANTREVILLE.

SMALL HAIL...AND WIND GUSTS UP TO 50 MPH ARE EXPECTED WITH THIS
STORM.

07