Severe Thunderstorm Warning 328, NWS Greenville-Spartanburg, SC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
253 PM EDT TUE AUG 4 2009

.SYNOPSIS...
A TROUGH OF LOW PRESSURE WILL REMAIN IN PLACE OVER THE AREA THROUGH
THURSDAY. A STRONG RIDGE OF HIGH PRESSURE WILL THEN DEVELOP OVER THE
SOUTHEAST ON FRIDAY AND STRENGTHEN THROUGH SUNDAY. WARM AND HUMID
CONDITIONS WILL PERSIST.

&&

.NEAR TERM /THROUGH WEDNESDAY/...
AT 1850Z...ISOLATED SLOW-MOVING TSRA EXISTED ACROSS THE NC MTNS AND
FOOTHILLS. COVERAGE OF SHRA/TSRA SHOULD BECOME NUM TO SCT OVER THE
NC MTNS AS A COOL POOL ASSOCIATED WITH AN UPSTREAM MCS SURGES ACROSS
THE NC MTNS AND FOOTHILLS. ISOLATED COVERAGE MAY DEVELOP ACROSS THE
PIEDMONT OF THE CAROLINAS AND NE GA. LAPS CAPE ANALYSIS INDICATES
THAT VALUES RANGE FROM 2000-2500 J/KG ACROSS THE WESTERN NC MTNS TO
1000-1500 J/KG ACROSS THE PIEDMONT. FZLVLS REMAIN AROUND 15
KFT...LIMITING SVR HAIL EVENTS. HOWEVER...DCAPE VALUES RANGE FROM
400-900 J/KG ACROSS THE CWA...POSSIBLY SUPPORTING A FEW SVR WIND
EVENTS THIS AFTERNOON AND EVENING. BY MID EVENING...COVERAGE SHOULD
DECREASE ACROSS THE CWA. I WILL KEEP A MENTION OF SCT TO ISO
SHRA/TSRA ACROSS THE NC MTNS. DEBRIS CLOUDS ARE FORECAST TO STREAM
NW TO SE OVERNIGHT...AIDING LOW TEMPERATURES A DEGREE OR TWO ABOVE
NORMAL.

WEDNESDAY...DEBRIS CLOUDS WILL CONTINUE TO STREAM ACROSS THE CWA.
HOWEVER...MILD THICKNESSES AND SLIGHT STRENGTHENING IN THE RETURN
FLOW SHOULD RESULT IN SLIGHTLY ABOVE NORMAL HIGH TEMPERATURES.
FORECAST SOUNDINGS INDICATE A SLIGHTLY WEAKER MID LEVEL INVERSION
ALONG WITH A LOWER LFC. REMNANTS MCS ACTIVITY/MCV/COOL POOL COMBINED
WITH DIURNAL INSTABILITY SHOULD RESULT IN NUM TO SCT SHRA AND TSRA
DURING THE AFTERNOON AND EVENING. MARGINAL WIND
SHEAR/INSTABILITY...SLIGHTLY LOWER FZLVL...AND DRY BL AIR MAY
SUPPORT SEVERAL SVR EVENTS. WE WILL MENTION IN THE HWO.

&&

.SHORT TERM /WEDNESDAY NIGHT THROUGH SATURDAY NIGHT/...
AS OF 230 PM TUESDAY...FRONT MOVES ACROSS CWA WED NIGHT THEN
STALLS/WASHES OUT OVER AREA. EVEN WITH COOLING EXPECT WEAK FORCING
OVERNIGHT SO KEPT CHANCE POPS UNTIL AFTER MIDNIGHT THEN SLIGHT
CHANCE THRU DAYBREAK. HIGH PRES REMAINS OFF THE SE COAST AND BRINGS
MOISTURE UP OVER AREA DURG DAY THU. GFS AND NAM BOTH SHOW WEAK
PVA...COMBINED WITH HEATING AND A SLY MOISTURE FEED...KEPT CHANCE
POPS THU. LOOK FOR SLIGHTLY BLO AVG HIGHS THU AFTN.

WEAK UPPER RIDGE BUILDS IN FROM THE W FRI WITH WEAK NVA INDICATED.
MOIST S FLOW CONTINUES IN LOW LEVELS HOWEVER...SO WITH TEMPS WARMING
TO ABOVE AVG AND WEAK UPSLOPE...HELD ON TO CHANCE AFTN POPS ACRS S
2/3 CWA...SLIGHT CHANCE N.

ALTHOUGH UPPER RIDGE TRIES TO BUILD IN FROM THE SW SAT...UPPER TROF
REMAINS ALONG E COAST WITH WEAK SHORTWAVES MOVG OVER CWA IN NW FLOW.
SFC BOUNDARY IS EXPECTED TO STAY WELL N OF THE AREA WHILE 850MB SW
FLOW BRINGS GULF MOISTURE UP OVER THE REGION. WITH THIS SUMMERTIME
PATTERN IN MIND...KEPT CHANCE POPS SAT. TEMPS SHOULD BE A CATEGORY
OR SO ABOVE AVG.

&&

.LONG TERM /SUNDAY THROUGH TUESDAY/...
AS OF 205 PM TUESDAY...BOTH THE 12Z GFS AND 00Z ECMWF HAS THE CENTER
OF THE UPPER RIDGE OVER GEORGIA OR ALABAMA AT 00Z SUNDAY.  THIS
RIDGE IS SLIGHTLY STRONGER FROM YESTERDAYS RUN.  THIS STRENGHTENS
THE CONFIDENCE THAT WE WILL HAVE HOT TEMPERATURES FORECAST TO REACH
THE MID 90S IN NON MOUNTAIN AREAS SUNDAY TO MONDAY.  DIURNAL
CONVECTION WILL CONTINUE...BUT INCREASE AS A COLD FRONT GETS CLOSER
INTO THE FIRST HALF OF THE WEEK.  THIS FRONT SHOULD REACH OUR AREA
FROM THE NORTH LATE TUESDAY OR TUESDAY NIGHT.  POPS WILL BE HIGHER
WITH THE PASSAGE OF THIS FRONT AND UPPER HEIGHTS WILL BE FALLING
INTO MID WEEK.  THEREFORE...THE HEAT WAVE SHOULD END WITH THIS FRONT
AND THE SET UP OF YET ANOTHER EAST STATES UPPER TROUGH.  THE EC HAS
GREATER AMPLITUDE AT THE END OF THIS FORECAST PERIOD.

&&

.AVIATION /19Z TUESDAY THROUGH SUNDAY/...
ISO SHRA AND TSRA WILL CONTINUE TO DEVELOP OVER THE HIGH TERRAIN
THROUGH THIS EVENING. KAVL AND KHKY WILL SEE THE GREATEST CHCS FOR
DEEP CONVECTION. HOWEVER...CHCS APPEAR TOO LOW TO MENTION IN THE
TAF...I WILL TEMPO CB IN THE SKY GROUP FOR KAVL BETWEEN 22-1Z.
OTHERWISE...CONDITIONS WILL REMAIN VFR THE REST OF THIS AFTERNOON
AND EVENING WITH LIGHT SOUTHWEST WINDS. OVERNIGHT...HIGH DEBRIS
CLOUDS WILL ADVANCE OUT OF THE NORTHWEST ACROSS THE WESTERN
CAROLINAS. A MARGINALLY DRY BL AND BKN HIGH CLOUDS SHOULD REDUCE THE
POTENTIAL FOR PRE DAWN FOG. I WILL TEMPO 5SM FOR BR AT KAVL AROUND
SUNRISE. AFTER SUNRISE...SOUTHWEST WINDS SHOULD STRENGTHEN TO 5-8
KTS. DEEP CONVECTION IS NOT EXPECTED TO INITIATE UNTIL MID TO LATE
AFTERNOON...WILL FORECAST SCT CU AROUND 050 KFT.

AT KCLT...A LIGHT NORTH TO VARIABLE WIND WILL REMAIN OVER THE
TERMINAL THROUGH MID AFTERNOON. OTHERWISE...WINDS SHOULD FAVOR A
SOUTHWEST DIRECTION WITH SPEEDS RANGING FROM 4-7 KTS. SCT VFR CU IS
EXPECTED TO LINGER THROUGH SUNSET. MTN SHRA/TSRA MAY SPREAD INTO THE
FOOTHILLS LATE THIS AFTERNOON AND EVENING...BUT SHOULD DISSIPATE
BEFORE REACHING THE PIEDMONT. HIGH DEBRIS CLOUDS WILL INCREASE FROM
THE NORTHWEST THIS EVENING...LIKELY BECOMING BKN BY 2Z AND REMAINING
THROUGH SUNRISE. THE COMBINATION OF THE HIGH SKY COVER AND 4-6
DEGREE DEWPOINT DEPRESSION WILL NOT FAVOR FOG FORMATION OVERNIGHT.
AFTER SUNRISE...SOUTHWEST WINDS SHOULD STRENGTHEN TO 5-8 KTS. DEEP
CONVECTION IS NOT EXPECTED TO INITIATE UNTIL MID TO LATE
AFTERNOON...WILL FORECAST SCT CU AROUND 050 KFT.

OUTLOOK...SHOWERS AND THUNDERSTORMS EXPECTED TO DEVELOP EACH
AFTERNOON AND EVENING FROM WEDNESDAY 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...DEO
NEAR TERM...NED
SHORT TERM...RB
LONG TERM...DEO
AVIATION...NED

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
333 PM EDT TUE AUG 4 2009

GAZ010-017-018-026-028-029-NCZ033-035>037-048>053-056>059-062>065-
068>072-082-501>510-SCZ001>014-019-051945-
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-
333 PM EDT TUE AUG 4 2009

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

.DAY ONE...THIS AFTERNOON AND TONIGHT.

THUNDERSTORMS WILL CONTINUE TO DEVELOP ACROSS THE NORTH CAROLINA
MOUNTAINS THIS AFTERNOON AND EVENING WITH SCATTERED STORMS MOVING
OUT ACROSS THE FOOTHILLS AND PIEDMONT. A FEW STORMS COULD PRODUCE
DAMAGING WIND GUSTS OR LARGE HAIL.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY.

ORGANIZED THUNDERSTORMS WILL LIKELY MOVE INTO THE NORTH CAROLINA
MOUNTAINS WEDNESDAY MORNING...THEN INTENSIFY WITH HEATING AND
INCREASING DYNAMICS...BEFORE SPREADING ACROSS THE FOOTHILLS AND
PIEDMONT DURING THE AFTERNOON AND EVENING. LARGE HAIL AND DAMAGING
WINDS WILL BE POSSIBLE WITH SOME OF THESE STORMS.

.SPOTTER INFORMATION STATEMENT...

NONE.

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
338 PM EDT TUE AUG 4 2009

NCZ056-042045-
CATAWBA-
338 PM EDT TUE AUG 4 2009

...A STRONG THUNDERSTORM WILL AFFECT SOUTHERN CATAWBA COUNTY THROUGH
445 PM EDT...

AT 337 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM 6 MILES SOUTH OF ICARD...OR 10 MILES SOUTHWEST OF
HICKORY...MOVING EAST AT 10 MPH.

THIS STORM WILL BE NEAR...
  NEWTON...
  MAIDEN...

SMALL HAIL...AND WIND GUSTS OF 30 TO 40 MPH ARE EXPECTED WITH THIS
STORM.

KRENTZ

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
402 PM EDT TUE AUG 4 2009

NCZ508-042100-
GREATER RUTHERFORD-
402 PM EDT TUE AUG 4 2009

...A STRONG THUNDERSTORM WILL AFFECT NORTH CENTRAL RUTHERFORD COUNTY
THROUGH 500 PM EDT...

AT 401 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM NEAR THERMAL CITY...OR 11 MILES NORTH OF
RUTHERFORDTON...MOVING SOUTH AT 10 MPH.

SMALL HAIL...AND WIND GUSTS OF 30 TO 40 MPH ARE EXPECTED WITH THIS
STORM.

INTENSE LIGHTNING IS OCCURRING WITH THIS STORM. IF OUTDOORS...STAY
AWAY FROM ISOLATED HIGH OBJECTS SUCH AS TREES.

KRENTZ

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
502 PM EDT TUE AUG 4 2009

NCZ509-510-SCZ007-042200-
EASTERN POLK-POLK MOUNTAINS-SPARTANBURG-
502 PM EDT TUE AUG 4 2009

...STRONG THUNDERSTORMS WILL AFFECT NORTHERN SPARTANBURG AND
SOUTHERN POLK COUNTIES THROUGH 600 PM EDT...

AT 501 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
STRONG THUNDERSTORMS ALONG A LINE EXTENDING FROM 5 MILES NORTHEAST OF
COLUMBUS TO 3 MILES WEST OF TRYON...MOVING SOUTHEAST AT 10 MPH.

* OTHER LOCATIONS AFFECTED INCLUDE BUT ARE NOT LIMITED TO LAKE
  BOWEN...TRYON...SALUDA...MILL SPRING...COLUMBUS...LANDRUM...
  INMAN...FINGERVILLE...CHESNEE AND CAMPOBELLO.

SMALL HAIL...AND WIND GUSTS OF 30 TO 40 MPH ARE EXPECTED WITH THESE
STORMS.

KRENTZ

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
528 PM EDT TUE AUG 4 2009

NCZ065-SCZ003-042230-
GREENVILLE MOUNTAINS-HENDERSON-
528 PM EDT TUE AUG 4 2009

...A STRONG THUNDERSTORM WILL AFFECT NORTHWESTERN GREENVILLE AND
SOUTHERN HENDERSON COUNTIES THROUGH 630 PM EDT...

AT 527 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM 3 MILES EAST OF JONES GAP STATE PARK...OR 13
MILES SOUTH OF HENDERSONVILLE...MOVING SOUTHEAST AT 15 MPH.

* OTHER LOCATIONS AFFECTED INCLUDE BUT ARE NOT LIMITED TO JONES GAP
  STATE PARK...TIGERVILLE...MARIETTA...CLEVELAND AND CAESARS HEAD.

WIND GUSTS OF 30 TO 40 MPH ARE EXPECTED WITH THIS STORM.

KRENTZ

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
558 PM EDT TUE AUG 04 2009

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

0538 PM     TSTM WND DMG     7 N BOILING SPRINGS SC  35.15N 81.98W
08/04/2009                   SPARTANBURG        SC   TRAINED SPOTTER

            SPOTTER REPORTED ONE TREE DOWN ON HIS PROPERTY AND UP TO
            1/4 INCH HAIL.

&&

JPT

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
609 PM EDT TUE AUG 4 2009

SCZ008-042300-
CHEROKEE-
609 PM EDT TUE AUG 4 2009

...A STRONG THUNDERSTORM WILL AFFECT CHEROKEE COUNTY THROUGH 700 PM
EDT...

AT 606 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM CAPABLE OF PRODUCING PEA SIZE HAIL...AND WIND
GUSTS OF 40 TO 50 MPH. THE STORM WAS LOCATED 6 MILES NORTHWEST OF
GAFFNEY...MOVING SOUTHEAST AT 10 MPH.

FREQUENT LIGHTNING AND VERY HEAVY RAINFALL ARE ALSO EXPECTED WITH
THIS STORM.

PEOPLE IN GAFFNEY...

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

LANE