Special Weather Statement, NWS Greenville-Spartanburg, SC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
244 PM EDT SAT AUG 6 2011

.SYNOPSIS...
HIGH PRESSURE WILL BUILD INTO THE REGION FROM THE SOUTH ON
SUNDAY...THOUGH ANOTHER WEAK FRONT MAY STALL OVER THE MOUNTAINS LATE
SUNDAY AND REMAIN THERE TO START THE WEEK.  THE FRONT GETS PUSHED
SOUTH OF OUR AREA IN MID WEEK AS HIGH PRESSURE FROM THE NORTH BRINGS
SOME DRIER WEATHER.

&&

.NEAR TERM /THROUGH SUNDAY/...
AS OF 145 PM...CONVECTION HAS FINALLY INITIATED ACRS THE NC MTNS
WITHIN LAST COUPLE OF HOURS. LAPS ANALYSIS SHOWS PLENTY OF SBCAPE
VERY MOIST BL. DEEP WLY FLOW (15-20 KTS) IS ENUF TO PUSH THE STORMS
SLOWLY EAST FROM THE MTNS INTO THE PIEDMONT THIS AFTN AND EVENING.
LIKELY POPS STILL LOOKS GOOD. THE NAM BUFKIT MBE VELOCITIES ARE VERY
SLOW ACRS THE PIEDMONT. SO POTENTIAL FOR TRAINING STORMS EXISTS. AND
GIVEN PWATS STILL OVER 2.00 INCHES...A SMALL HEAVY RAIN THREAT STILL
EXISTS TODAY. SEVERE THREAT IS STILL LOW...BUT WITH FREEZING LEVELS
DOWN TO 14.5 TO 15 KFT WITH SOME FLOW...IT IS A LITTLE HIGHER THAT
LAST FEW DAYS.

REST OF TONIGHT...QUASI-ZONAL FLOW ACRS THE NORTHERN TIER OF THE
CONUS CONTINUES. GUIDANCE IN AGREEMENT ON A 700 MB JETLET TRACKING
ACRS THE OHIO VALLEY OVERNIGHT. VERY GOOD MOISTURE FLUX AND
LINGERING INSTBY MAY SUSTAIN CONVECTION UPSTREAM THRU THE NIGHT.
CONVECTION HAS BEEN ONGOING ALL DAY ACRS CENTRAL KY/TN...AND THE
DEBRIS MOISTURE FROM THAT CLUSTER WILL WORK INTO THE CWFA. SO MOSTLY
CLOUDY SKIES EXPECTED WITH DWINDLING CONVECTION EXPECTED. SOME
UPSTREAM PRECIP MAY MOVE INTO THE NC MTNS BEFORE DAYBREAK. LOWS WILL
CONTINUE TO BE MILD UNDER CLOUDS AND HUMIDITY (UPR 60S MTNS AND
LWR-MID 70S PIEDMONT).

SUNDAY...OVERALL W/NWLY FLOW CONTINUES TO STRENGTHEN AS TROFINESS
AMPLIFIES SLIGHTLY OVER THE NORTHEAST STATES. A WEAKENING MCV IS
PROGGED TO TRACK THRU THE CWFA DURING THE AFTN. SLIGHTLY BETTER
DOWNSLOPE EAST OF THE MTNS MAY MIX DWPTS INTO THE MID 60S...BUT
STILL EXPECT AT LEAST SCATTERED CONVECTION TO DEVELOP (POSSIBLY
NUMEROUS SHWRS/TSTMS IN THE MTNS). HYDRO CONCERNS SHUD BE LOWER WITH
THE INCREASED FLOW...BUT SEVERE THREAT WILL CONTINUE (MAINLY ISOLD
WET MICROBURSTS). TEMPS BACK INTO THE UPR 80S MTN VLYS AND MID-UPR
90S PIEDMONT...BUT MIXED DWPTS SHUD KEEP HEAT INDEX BELOW 105.

&&

.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
AS OF 100 PM SAT...THE UPPER LEVEL JET STREAM SHOULD STRETCH
FROM THE OH VALLEY TO SRN NEW ENGLAND SUN NIGHT THROUGH TUE AS A
BROAD BUT SHALLOW TROUGH DEVELOPS OVER THE E. THIS WILL ALLOW
RIPPLES OF UPPER DIVERGENCE AND OCCASIONAL SHORTWAVES TO CROSS THE
FORECAST AREA...ESPECIALLY THE NRN TIER...THROUGH THE PERIOD. THE
PROFILES DO SHOW SOME MID AND UPPER DRYING IN THE WNW FLOW ON SUN
NIGHT AND MON. HOWEVER...UPSTREAM MCS DEVELOPMENT OVER THE MIDWEST
IS VERY LIKELY AND THE SRN APPALACHIANS WILL SIT SQUARELY DOWNSTREAM
OF ANY ACTIVITY IN THE WNW FLOW ALOFT. WILL THUS NEED SOLID WRN MTN
CHC POPS THROUGH THE PERIOD. A SFC TROUGH WILL REMAIN ACROSS THE
PIEDMONT MON THROUGH TUE...BUT PRECIP CHANCES WILL BE MORE DIURNAL
IN NATURE THERE...AND GENERALLY IN THE LOWER CHANCE RANGE. IN THE
IMPROVING WESTERLY FLOW ALOFT...20 TO 30 KT OF 6 KM BULK SHEAR COULD
BE REALIZED AT TIMES. SOME ORGANIZATION OF DISCRETE CONVECTIVE CELLS
COULD BE POSSIBLE ACROSS FOOTHILL AND PIEDMONT AREAS EACH AFTERNOON
IF THIS SHEAR MATERIALIZES. HEAT INDEX VALUES COULD APPROACH 105
ALONG THE SE FRINGE MON AFTN...BUT TEMPS SHOULD BE A CATEGORY COOLER
ON TUE IF A WEAK FRONTAL ZONE LAYS OVER INTO THE AREA FROM THE NW AS
EXPECTED.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
AS OF 230 PM SATURDAY...THE GFS AND ECMWF CONTINUE TO BE IN FAIRLY
GOOD AGREEMENT WITH THE UPPER LEVEL TROFINESS OVER THE EASTERN PART
OF THE NATION.  FOR THE SECOND HALF OF THE UPCOMING WEEK.  THE
SURFACE FRONT WILL PUSH SOUTH OF THE AREA TUESDAY NIGHT WITH A
SECONDARY FRONT COMING DOWN FROM THE NORTH ON WEDNESDAY BUT LITTLE
IF ANY MOISTURE WILL BE PRESENT.  GENERALLY DRY WEATHER IS EXPECTED
INTO NEXT WEEKEND. THE GFS HOLDS OFF THE MOISTURE UNTIL FRIDAY THEN
BRINGS IN MINOR VORTS FROM THE WEST ALONG WITH ITS EASTERN GULF LOW.
THE ECMWF KEEPS ALL DRY OVER OUR REGION UNTIL LATE SATURDAY BUT
MOISTURE IS NOT AS ROBUST AS IN THE GFS.  MOISTURE WILL CONTINUE TO
INCREASE AHEAD THE NEXT APPROACHING COLD FRONT WHICH WILL ARRIVE
FROM THE NORTHWEST NEXT SUNDAY.  TEMPERATURES WILL BE ABOVE NORMAL
BY ONE TO TWO CATEGORIES THROUGH THE PERIOD.

&&

.AVIATION /19Z SATURDAY THROUGH THURSDAY/...
AT KCLT...CIGS SHUD LIFT TO VFR BY 18Z...WITH VFR CONDITIONS
EXPECTED INTO THE EVENING. THE EXCEPTION WILL BE SHRA AND
TSRA...WHICH ARE STILL EXPECTED TO BECOME NUMEROUS ACRS THE AREA
LATE AFTN AND EVENING. THEY ARE NOT ORGANIZED SUCH THAT NO TEMPO CAN
BE MADE YET. BUT THE MAIN WINDOW OF GREATEST COVERAGE IS EXPECTED TO
BE 20Z TO 02Z. OVERNIGHT...THERE WILL BE PLENTY OF MID-UPR LEVEL
CLOUDINESS WHICH SHUD LIMIT FOG DEVELOPMENT. BUT CONSENSUS AMONGST
GUIDANCE IS FOR MVFR HZ TO DEVELOP BY DAYBREAK SUNDAY. WINDS WILL BE
LIGHT OR CALM AND FAVOR A SWLY DIRECTION THRU THE PERIOD.

ELSEWHERE...ALL SITES EXPECTED TO BE VFR BY 18Z...WITH MAIN CONCERN
GOING FORWARD BEING CONVECTION. DEEP CONVECTION THIS AFTERNOON
EXPECTED TO BECOME NUMEROUS BEFORE DISSIPATING THIS EVENING. AT TIME
OF ISSUANCE...STORMS FILLING IN JUST WEST OF KAVL. SO CONFIDENCE
HIGH ENUF FOR DIRECT IMPACT TO ADD TEMPO IFR IN TSRA. STORMS WILL
ROLL OFF THE MTNS TO AFFECT THE UPSTATE SITES AND KHKY IN THE 19 TO
02Z TIME FRAME. MID LEVEL CLOUDINESS WILL LINGER THRU THE OVERNIGHT
AND LIMIT LATE NIGHT VSBY RESTRICTIONS (FOR NOW JUST HAVE MVFR AT
KAVL).

OUTLOOK...MOISTURE WILL GRADUALLY DIMINISH INTO EARLY NEXT WEEK AS
LOW LEVEL FLOW TURNS TOWARD THE WEST. HOWEVER...CHANCES FOR ISOLATED
TO WIDELY SCATTERED AFTERNOON/EVENING SHOWERS/TS WILL REMAIN THROUGH
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...DEO
NEAR TERM...ARK
SHORT TERM...HG
LONG TERM...DEO
AVIATION...ARK

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
417 AM EDT SAT AUG 6 2011

GAZ010-017-018-026-028-029-NCZ033-035>037-048>053-056>059-062>065-
068>072-082-501>510-SCZ001>014-019-070830-
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-
417 AM EDT SAT AUG 6 2011

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

.DAY ONE...TODAY AND TONIGHT.

SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS ARE EXPECTED TO
DEVELOP OVER THE REGION TODAY. STORMS SHOULD MOVE A LITTLE MORE
QUICKLY TODAY THAN THEY DID ON FRIDAY. HOWEVER...THE AIRMASS OVER
THE WESTERN CAROLINAS AND NORTHEAST GEORGIA REMAINS EXTREMELY
MOIST AND SOME THUNDERSTORMS WILL PRODUCE LOCALLY EXCESSIVE
RAINFALL. A FEW STORMS MAY ALSO PRODUCE SMALL AREAS OF DAMAGING
WINDS.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY.

A WEAK FRONT WILL STALL OVER THE MOUNTAINS ON SUNDAY. THE FRONT WILL
PROVIDE A FOCUS FOR SCATTERED THUNDERSTORMS SUNDAY AND MONDAY.
SOME OF THE THUNDERSTORMS MAY BECOME SEVERE AND PRODUCE DAMAGING
WINDS.

.SPOTTER INFORMATION STATEMENT...

NONE.

14

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
521 PM EDT SAT AUG 6 2011

SCZ013-014-062200-
CHESTER-UNION-
521 PM EDT SAT AUG 6 2011

...A STRONG THUNDERSTORM WILL AFFECT NORTHEASTERN UNION AND WESTERN
CHESTER COUNTIES THROUGH 600 PM EDT...

AT 517 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM 3 MILES SOUTHWEST OF ADAMSBURG...OR 4 MILES
NORTHEAST OF UNION...MOVING EAST AT 15 MPH.

THIS STORM WILL BE NEAR...
  LOCKHART...

WIND GUSTS OF 30 TO 40 MPH ARE EXPECTED WITH THIS STORM. BRIEF HEAVY
RAIN CAN ALSO BE EXPECTED.

LAT...LON 3469 8168 3487 8163 3485 8147 3484 8146
      3482 8147 3483 8125 3481 8115 3457 8122

RB

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
535 PM EDT SAT AUG 6 2011

NCZ071-072-062215-
CABARRUS-MECKLENBURG-
535 PM EDT SAT AUG 6 2011

...A STRONG THUNDERSTORM WILL AFFECT NORTHERN MECKLENBURG AND WESTERN
CABARRUS COUNTIES THROUGH 615 PM EDT...

AT 534 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM 4 MILES WEST OF HUNTERSVILLE...OR 13 MILES
NORTHWEST OF UNC CHARLOTTE...MOVING SOUTHEAST AT 15 MPH.

THIS STORM WILL BE NEAR...
  HUNTERSVILLE...
  CHARLOTTE MOTOR SPEEDWAY...

WIND GUSTS OF 30 TO 40 MPH ARE EXPECTED WITH THIS STORM. BRIEF HEAVY
RAIN CAN ALSO BE EXPECTED.

LAT...LON 3519 8066 3534 8096 3535 8096 3536 8093
      3537 8098 3539 8096 3544 8096 3545 8094
      3547 8095 3551 8093 3542 8054

RB

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
558 PM EDT SAT AUG 6 2011

NCZ037-057-062245-
DAVIE-ROWAN-
558 PM EDT SAT AUG 6 2011

...A STRONG THUNDERSTORM WILL AFFECT NORTHERN ROWAN AND SOUTHERN
DAVIE COUNTIES THROUGH 645 PM EDT...

AT 555 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM NEAR COOLEEMEE...OR 5 MILES SOUTH OF
MOCKSVILLE...MOVING EAST AT 15 MPH.

THIS STORM WILL BE NEAR...
  COOLEEMEE...
  SPENCER...

WIND GUSTS OF 30 TO 40 MPH ARE EXPECTED WITH THIS STORM. BRIEF HEAVY
RAIN CAN ALSO BE EXPECTED.

LAT...LON 3562 8030 3576 8071 3594 8064 3589 8041
      3585 8038 3582 8047 3579 8047 3577 8045
      3574 8045 3572 8038 3573 8034 3571 8032
      3568 8033 3564 8029

RB

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
607 PM EDT SAT AUG 6 2011

SCZ014-062245-
CHESTER-
607 PM EDT SAT AUG 6 2011

...A STRONG THUNDERSTORM WILL AFFECT SOUTHERN CHESTER COUNTY THROUGH
645 PM EDT...

AT 603 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM 4 MILES SOUTHEAST OF LEEDS...OR 10 MILES
SOUTHWEST OF CHESTER...MOVING EAST AT 10 MPH.

THIS STORM WILL BE NEAR...
  BLACKSTOCK...

WIND GUSTS OF 30 TO 40 MPH ARE EXPECTED WITH THIS STORM. BRIEF HEAVY
RAIN CAN ALSO BE EXPECTED.

LAT...LON 3456 8117 3456 8142 3457 8143 3464 8142
      3471 8140 3466 8099 3454 8103

RB

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
637 PM EDT SAT AUG 6 2011

NCZ071-072-062315-
CABARRUS-MECKLENBURG-
637 PM EDT SAT AUG 6 2011

...A STRONG THUNDERSTORM WILL AFFECT EASTERN MECKLENBURG AND SOUTHERN
CABARRUS COUNTIES THROUGH 715 PM EDT...

AT 633 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM NEAR UNC CHARLOTTE...MOVING EAST AT 20 MPH.

THIS STORM WILL BE NEAR...
  HARRISBURG...
  CONCORD...
  MIDLAND...

WIND GUSTS OF 30 TO 40 MPH ARE EXPECTED WITH THIS STORM. A PERIOD OF
HEAVY RAIN CAN ALSO BE EXPECTED.

LAT...LON 3521 8048 3519 8051 3519 8053 3521 8055
      3520 8056 3525 8083 3542 8082 3541 8036
      3539 8036

RB

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
700 PM EDT SAT AUG 6 2011

NCZ057-062330-
ROWAN-
700 PM EDT SAT AUG 6 2011

...A STRONG THUNDERSTORM WILL AFFECT SOUTHEASTERN ROWAN COUNTY
THROUGH 730 PM EDT...

AT 658 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM 3 MILES SOUTHWEST OF HIGH ROCK...OR 14 MILES
SOUTHEAST OF SALISBURY...MOVING EAST AT 10 MPH.

WIND GUSTS OF 30 TO 40 MPH ARE EXPECTED WITH THIS STORM. A PERIOD OF
HEAVY RAIN CAN ALSO BE EXPECTED.

LAT...LON 3551 8037 3550 8040 3567 8034 3567 8030
      3564 8029 3564 8026 3558 8020 3555 8020
      3552 8018 3550 8018

RB