Severe Thunderstorm Warning 406, NWS Greenville-Spartanburg, SC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
310 PM EDT SAT AUG 25 2007

.SYNOPSIS...
AN UPPER LEVEL DISTURBANCE AND ASSOCIATED COLD FRONT MOVE IN FROM
THE NORTHWEST ON SUNDAY...BECOME STATIONARY...AND SLOWLY DISSIPATE
AS THE UPPER RIDGE BUILDS BACK OVER OUR REGION DURING THE FIRST HALF
OF THE WEEK.

&&

.NEAR TERM /THROUGH SUNDAY/...
EXPECT AFTN AND EVENING CONVECTION TO DISSIPATE WITH LOSS OF DAYTIME
HEATING. SOME STORMS WILL BE SEVERE...WITH DAMAGING WINDS BEING THE
GREATEST THREAT. THE GFS HAS QPF OVERNIGHT ACROSS THE MTNS...WITH
THE NAM GOING DRY BY 6Z SUNDAY. THE DIFFERENCES IN THE TIMING OF A
WEAK VORT MAX AND PASSAGE OF WIND SHIFT/PRE-FRONTAL TROUGH ACROSS
THE MTNS IS RATHER SUBTLE (ABOUT 6 HOURS). BOTH HAVE SOME
INSTABILITY WELL INTO THE OVERNIGHT HOURS. SO GIVEN THE POTENTIAL
FOR SOME LIFT ACROSS THE MTNS...ESPECIALLY THE WESTERN SLOPES OF THE
GREAT SMOKIES AND CENTRAL NC MTNS...KEPT SLIGHT CHC POP FOR THUNDER
OVERNIGHT. COLD FRONT APPROACHES AND IS PROGGED TO BE WITHIN THE
CWFA BY 18Z SUNDAY. AGAIN...PLENTY OF INSTABILITY IN PLACE. SO WENT
WITH SOLID CHANCE EVERYWHERE (40-50%) FOR SUNDAY AFTN. THE POTENTIAL
FOR PULSE SEVERE THUNDERSTORMS SHOULD BE A BIT HIGHER SUNDAY WITH
INCREASED COVERAGE OF THUNDERSTORMS EXPECTED. WITH MORE CLOUD COVER
AND LOWER HEIGHTS ALOFT...MAX TEMPS WILL BE IN THE LOWER 90S
PIEDMONT...80S MTN VALLEYS.

&&

.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
SHORT WAVE TROF MOVES OUT OF THE AREA SUNDAY NIGHT THEN WEAK UPPER
RIDGING RETURNS FOR MONDAY AND TUESDAY. NAM APPEARED TO BE THE
OUTLIER WITH THE GULF COAST LOW SHEARING OUR AND MOVING NORTHEAST
INTO OUR AREA. OTHERWISE...ITS PATTERN IS SIMILAR TO THE GFS.
FRONTAL SYSTEM MOVES TO OUR SOUTH SUNDAY NIGHT AND STALLS THERE FOR
MONDAY. SCATTERED CONVECTION SUNDAY EVENING BECOMES MORE ISOLATED
AFTER MIDNIGHT...BUT COULD LINGER TOWARD MORNING CLOSER TO THE FRONT.
ABOVE NORMAL LOWS EXPECTED SUNDAY NIGHT. MODELS HAVE DECENT LOW
LEVEL MOISTURE AND CONVERGENCE ALONG WITH INSTABILITY MONDAY.
HOWEVER...THE GFS KEEPS CONVECTION MAINLY OVER THE SOUTH WHILE THE
NAM HAS IT OVER THE MTNS AND SOUTHEAST OF THE CWFA. WITH LITTLE IN
THE WAY OF SYNOPTIC FORCING...EXPECT ISOLATED DIURNAL CONVECTION
WEST OF THE BLUE RIDGE WITH SCT CONVECTION ALONG AND EAST OF IT.
ABOVE NORMAL HIGHS MONDAY BACK INTO THE LOWER 90S OUTSIDE OF THE
MTNS AND NEAR 90 MTN VALLEYS.

EXPECT CONVECTION TO BECOME ISOLATED MONDAY NIGHT AND END BY
MIDNIGHT WITH LOSS OF HEATING AND LACK OF SYNOPTIC FORCING. LOWS NEAR
NORMAL NC FOOTHILLS/PIEDMONT...BUT A FEW DEGREES ABOVE NORMAL
ELSEWHERE.

FRONT WASHES OUT ON TUESDAY...WITH SOME SORT OF COASTAL LOW FORMING
OFF CAPE HATTERAS. LESS IN THE WAY OF LOW LEVEL CONVERGENCE BUT
MOISTURE STILL DECENT. ATMOSPHERE REMAINS UNSTABLE...BUT MODELS
STILL CANNOT QUITE AGREE ON WHICH LOCATION HAS THE BEST CHC OF
CONVECTION. USING MODEL BLEND...HAVE SCATTERED CONVECTION ALONG AND
SOUTH OF I-85 AND ISOLATED NORTH. HIGHS A DEGREE OR TWO COOLER THAN
MONDAY...BUT STILL SEVERAL DEGREES ABOVE NORMAL.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
UPPER RIDGE WEAKENS AND RETROGRADES WEDNESDAY AND IS REPLACED BY A
TROF THURSDAY. THIS TROF HOLDS ON THROUGH SATURDAY. SFC HIGH
PRESSURE MOVES IN WEDNESDAY. COULD SEE SOME ISOLATED DIURNAL
CONVECTION OVER THE MTNS...BUT MOISTURE AND INSTABILITY LIMITED.
ABOVE NORMAL TEMPERATURES ONCE AGAIN TUE NITE AND WEDNESDAY. FRONTAL
SYSTEM MOVES IN THURSDAY AND REMAINS STALLED JUST TO OUR SOUTH
FRIDAY AND SATURDAY. ISOLATED DIURNAL CONVECTION THURSDAY WITH ABOVE
NORMAL TEMPS...BUT MAYBE A DEGREE OR TWO COOLER THAN WEDNESDAY. THEN
THE MUCH ANTICIPATED AND HOPED FOR PATTERN CHANGE STILL FORECAST
FRIDAY AND SATURDAY. IF THIS OCCURS...THEN WE SHOULD SEE SCATTERED
CONVECTION WITH NEAR NORMAL LOWS AND BELOW NORMAL HIGHS.

&&

.AVIATION /19Z SATURDAY THROUGH THURSDAY/...
SCT SHWRS/TSTMS...HAVE DEVELOPED OVER THE PAST COUPLE OF HOURS OVER
THE MTNS W OF KAVL. EXPECT SIMILAR COVERAGE AS YESTERDAY (MTNS AND
WRN PIEDMONT (KAND/KGMU/KGSP)...WITH ISOLD COVERAGE AROUND KCLT.
CONTINUED CB CLOUDS ALL AREAS EXCEPT KCLT...WITH VCTS AT KAVL.

COLD FRONT APPROACHES THE REGION SUNDAY SO EXPECT LARGER COVERAGE OF
AFTN-EVE CONVECTION SUNDAY INTO THE FIRST PART OF NEXT WEEK. PATCHY
MORNING FOG WILL ALSO BE POSSIBLE EACH DAY...ESPECIALLY MTN VALLEYS.

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...AIR QUALITY ACTION DAY UNTIL 9 PM EDT THIS EVENING FOR NCZ036-
     037-057-069>072-082.
SC...NONE.

&&

SYNOPSIS...RWH
NEAR TERM...ARK
SHORT TERM...RWH
LONG TERM...RWH
AVIATION...ARK

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
413 PM EDT SAT AUG 25 2007

GAZ010-017-018-026-028-029-NCZ033-035-048>053-056-058-059-062>065-
068-501>510-SCZ001>014-019-262015-
RABUN-HABERSHAM-STEPHENS-FRANKLIN-HART-ELBERT-AVERY-ALEXANDER-
MADISON-YANCEY-MITCHELL-SWAIN-HAYWOOD-BUNCOMBE-CATAWBA-GRAHAM-
NORTHERN JACKSON-MACON-SOUTHERN JACKSON-TRANSYLVANIA-HENDERSON-
CLEVELAND-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-
413 PM EDT SAT AUG 25 2007

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

.DAY ONE...THIS AFTERNOON AND TONIGHT

A FEW SEVERE STORMS WILL BE POSSIBLE THIS EVENING. THE MAIN SEVERE
THREAT IS EXPECTED TO BE DAMAGING WINDS.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY

A FEW SEVERE STORMS WILL BE POSSIBLE AGAIN SUNDAY AFTERNOON AND
EARLY EVENING. THE MAIN SEVERE THREAT IS EXPECTED TO BE DAMAGING
WINDS. HEAT INDEX VALUES WILL BE AROUND 100 DEGREES OVER THE
SOUTHERN PORTIONS OF NORTHEAST GEORGIA AND THE SOUTHERN AND
EASTERN UPSTATE SUNDAY AFTERNOON.

SOME SEVERE WEATHER IS AGAIN POSSIBLE LATE MONDAY.

.SPOTTER INFORMATION STATEMENT...

WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER
CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES.

NCZ036-037-057-069>072-082-262015-
IREDELL-DAVIE-ROWAN-LINCOLN-GASTON-MECKLENBURG-CABARRUS-UNION NC-
413 PM EDT SAT AUG 25 2007

...AIR QUALITY ACTION DAY IN EFFECT UNTIL 9 PM EDT THIS EVENING...

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PIEDMONT NORTH CAROLINA.

.DAY ONE...THIS AFTERNOON AND TONIGHT

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

   AIR QUALITY ACTION DAY.

ISOLATED THUNDERSTORMS WILL CONTINUE INTO THE EARLY EVENING OVER
THE AREA.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY

A FEW SEVERE STORMS WILL BE POSSIBLE SUNDAY AFTERNOON AND EARLY
EVENING. THE MAIN SEVERE THREAT IS EXPECTED TO BE DAMAGING WINDS.
HEAT INDEX VALUES WILL BE AROUND 100 DEGREES SUNDAY AFTERNOON.

SOME SEVERE WEATHER IS AGAIN POSSIBLE LATE MONDAY.

.SPOTTER INFORMATION STATEMENT...

WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER
CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES.

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
419 PM EDT SAT AUG 25 2007

SCZ013-252045-
UNION-
419 PM EDT SAT AUG 25 2007

...A STRONG THUNDERSTORM WILL AFFECT WESTERN UNION COUNTY THROUGH 445
PM EDT...

AT 419 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM 3 MILES NORTH OF CROSS KEYS...OR 9 MILES
SOUTHWEST OF UNION...MOVING SOUTHEAST AT 5 MPH.

THIS STORM WILL BE NEAR...
  CROSS KEYS BY 435 PM EDT.

PEA SIZE 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. 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.

HG

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
422 PM EDT SAT AUG 25 2007

SCZ012-252045-
LAURENS-
422 PM EDT SAT AUG 25 2007

...A STRONG THUNDERSTORM WILL AFFECT EASTERN LAURENS COUNTY THROUGH
445 PM EDT...

AT 422 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM 5 MILES EAST OF JOANNA...OR 13 MILES NORTHWEST OF
NEWBERRY. THIS STORM WAS NEARLY STATIONARY.

PEA SIZE 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. 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.

HG

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
445 PM EDT SAT AUG 25 2007

SCZ012-252130-
LAURENS-
445 PM EDT SAT AUG 25 2007

...A STRONG THUNDERSTORM WILL AFFECT EASTERN LAURENS COUNTY THROUGH
530 PM EDT...

AT 445 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM 3 MILES SOUTH OF CROSS KEYS...OR 12 MILES
SOUTHWEST OF UNION...MOVING SOUTHWEST AT 5 MPH.

THIS STORM WILL BE NEAR...
  4 MILES NORTHEAST OF CLINTON BY 530 PM EDT.

PEA SIZE 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. 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.

HG

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
508 PM EDT SAT AUG 25 2007

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

0432 PM     TSTM WND DMG     CROSS KEYS              34.63N 81.78W
08/25/2007                   UNION              SC   COUNTY OFFICIAL

            TREES AND POWER LINE BLOWN DOWN ON OLD BUNCOMBE ROAD. PEA
            SIZED HAIL ALSO REPORTED.

&&

JEFFT

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
513 PM EDT SAT AUG 25 2007

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

0500 PM     TSTM WND DMG     2 E CLINTON             34.48N 81.83W
08/25/2007                   LAURENS            SC   COUNTY OFFICIAL

            TREES DOWN ALONG I-26 JUST EAST OF CLINTON.

&&

BSH

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
515 PM EDT SAT AUG 25 2007

SCZ007-008-252145-
CHEROKEE-SPARTANBURG-
515 PM EDT SAT AUG 25 2007

...A STRONG THUNDERSTORM WILL AFFECT NORTHEASTERN SPARTANBURG AND
WESTERN CHEROKEE COUNTIES THROUGH 545 PM EDT...

AT 510 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM NEAR CHESNEE...OR 14 MILES WEST OF GAFFNEY...
MOVING SOUTH AT 15 MPH.

THIS STORM WILL BE NEAR...
  MAYO BY 525 PM EDT.
  COWPENS BY 545 PM EDT.

PEA SIZE 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. 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.

HG