Special Weather Statement, NWS Greenville-Spartanburg, SC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
609 PM EDT THU AUG 2 2012

.SYNOPSIS...
WEAK HIGH PRESSURE WILL REMAIN ACROSS THE AREA THROUGH SATURDAY. THE
HIGH PRESSURE WILL START TO BREAK DOWN FROM THE NORTHWEST ON
SUNDAY...WITH A SURFACE COLD FRONT APPROACHING THE REGION
MONDAY...AND LINGERING IN THE VICINITY THROUGH WEDNESDAY.

&&

.NEAR TERM /THROUGH FRIDAY/...
2200 UTC UPDATE...POPS HAVE BEEN RAISED IN UNION COUNTY NC..AND SKY
COVER UPDATED FROM SATELLITE IMAGERY.

PREVIOUS DISCUSSION...IT/S A LITTLE SURPRISING THAT CONVECTION HAS
BEEN AS STRONG AS IT/S BEEN OVER THE NC FOOTHILLS THE PAST HOUR AS
THE WESTERN CAROLINAS ARE ON THE BACK SIDE OF A VIGOROUS SHORT WAVE
OVER THE NC COASTAL PLAIN. HOWEVER...THERE IS A WEAK SFC BNDRY
TRAILING THIS FEATURE WHICH IS EVIDENT AS A LINE OF ENHANCED CU THAT
CURRENTLY EXTENDS ACROSS THE CHARLOTTE METRO AREA...NORTHWESTWARD TO
THE BLUE RIDGE WEST OF MARION. DESPITE THE UNFAVORABLE SYNOPTIC
SCALE FORCING...STORMS HAVE BEEN ABLE TO DEVELOP ALONG THIS
BNDRY...WITH WEAKER CONVECTION INITIATING OVER THE MOUNTAINS. DCAPE
VALUES RANGE FROM 1100-1500 ACROSS THE FORECAST AREA ACCORDING TO
THE SPC MESO-ANALYSIS AND THE STRONGER STORMS THAT FORM ARE LIKELY
TO PRODUCE DAMAGING WINDS AND SOME HAIL. IN FACT...THE CONVECTION IS
LIABLE TO LAST A WAYS INTO THE EVENING AS THE STORMS WILL PRODUCE
POTENT OUTFLOW BNDRYS. HOPEFULLY THEY WILL SUBSIDE AFTER SUNSET
CONSIDERING THE LACK OF ANY GOOD UPSTREAM SHORTWAVES. I/D EXPECT
STORMS THIS AFTN TO PRODUCE WIND DAMAGE WITH 60 DBZ CORES AT 19-20
KFT AND/OR 55 DBZ CORES UP AROUND 24 KFT.

LATE IN THE DAY ON FRIDAY THE NAM AND GFS AGREE IN BRINGING AN MCV
INTO THE MTNS...OR PERHAPS A LITTLE WEST OF THE REGION. IN
FACT...THE OVERALL SYNOPTIC PATTERN SUPPORTS INCREASING TROUGHINESS
OVER THE DEEP SOUTH BETWEEN TWO STRONG RIDGES...ONE OVER THE PLAINS
AND ONE OVER THE WESTERN ATLANTIC. LAYER RH VALUES WILL BEGIN TO
INCREASE ACROSS THE REGION LATE FRIDAY...RESULTING IN AN
INCREASINGLY FRIENDLY ENVIRONMENT FOR CONVECTION. POPS HAVE BEEN
RAISED INTO THE HIGH CHANCE TO LOW LIKELY RANGE OVER THE MTNS. THE
PIEDMONT WILL REMAIN UNDER WEAK NVA THROUGH THE DAYLIGHT HOURS AND
POPS HAVE BEEN KEPT LOWER IN THESE ZONES. EVEN WITH THE MOISTENING
ATMOSPHERE...A FEW SEVERE STORMS ARE A GOOD BET IN THE
AFTN...ESPECIALLY OVER THE MOUNTAINS AND FOOTHILLS.

&&

.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
AS OF 230 PM THU...THE SHORT RANGE WILL FEATURE THE PASSAGE OF A
WEAK WAVE ALOFT LATE FRIDAY NIGHT AND SATURDAY MORNING...WHICH MAY
SERVE TO KEEP CONVECTION FIRING WELL INTO THE OVERNIGHT HOURS GIVEN
THE RELATIVELY DEEP MOISTURE THAT SHOULD BE IN PLACE. SEE NOTHING
THAT SHOULD DISCOURAGE DEEP CONVECTION FROM DEVELOPING WITH DAYTIME
HEATING AGAIN ON SATURDAY...WITH STORMS BECOMING NUMEROUS ACROSS THE
HIGHER TERRAIN LATE IN THE DAY. THE STORMS SHOULD PUSH OFF THE BLUE
RIDGE IN THE EVENING AND EVENTUALLY DIE OFF LATE AT NIGHT...AS
USUAL...SINCE THE UPPER WAVE SHOULD NOT BE AROUND TO HELP MAINTAIN.
EXPECT MORE OF THE SAME ON SUNDAY AS THE SETUP DOES NOT REALLY
CHANGE MUCH. PROFILES LOOK RELATIVELY MOIST AND TEMPS ARE RELATIVELY
WARM AT MID LEVELS...WHICH MAY SERVE TO CUT BACK ON SEVERE STORM
CHANCES. TEMPS WILL STAY NEAR CLIMO.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AS OF 115 PM THU...THE LATEST GUIDANCE THROUGH THE MEDIUM RANGE
FAVORS MAINTAINING A WEAKNESS AT 500 MB BETWEEN THE ATLANTIC
SUBTROPICAL HIGH AND THE ANTICYCLONE OVER THE SOUTHWESTERN U.S.. THE
GFS LEAVES AN AREA OF WEAK Q CONVERGENCE DRAPED ACROSS THE WESTERN
CAROLINAS THROUGH WEDNESDAY AND KEEPS THE RIGHT ENTRANCE REGION OF
THE UPPER JET OVERHEAD. AT THE SURFACE...AN OLD FRONTAL BOUNDARY
SHOULD BE STALLED ACROSS THE OH VALLEY. A LIGHT S OR SW FLOW AT LOW
LEVELS WILL MAINTAIN A SUPPLY OF MOISTURE. IN GENERAL...THIS WOULD
APPEAR TO FAVOR AN ENHANCEMENT TO OUR USUAL DIURNAL THUNDERSTORM
CHANCES...SO THAT IS ESSENTIALLY WHAT WILL BE PUT IN THE FCST. THERE
MIGHT BE A SLIGHTLY IMPROVED CHANCE ON WEDNESDAY AS AN UPPER LEVEL
FEATURE MOVES BY TO OUR NORTH. ANY OF THE DAYS THROUGH MID WEEK
COULD SEE NUMEROUS STORMS...BUT FOR NOW WILL LIMIT THE CHANCE TO THE
40 PCT RANGE. THURSDAY SHOULD HAVE SLIGHTLY DIMINISHED CHANCES IN
THE WAKE OF THE NORTHERN WAVE. TEMPS IN GENERAL WILL STAY NEAR
CLIMATOLOGY WITH THE WARMEST DAY BEING THURSDAY.

&&

.AVIATION /22Z THURSDAY THROUGH TUESDAY/...
AT KCLT...A LINE OF TOWERING CU HAVE DEVELOPED IN A WEST TO EAST
ORIENTED BAND ACROSS THE AIRFIELD. CLOSER TO THE MOUNTAINS
THUNDERSTORMS HAVE ALREADY DEVELOPED ALONG THIS BAND. THEY HAVE ALSO
DEVELOPED AROUND 40 MI EAST OF THE AIRFIELD ALONG THE BAND AS WELL.
THERE IS A GOOD CHANCE THAT TSTMS WILL FIRE CLOSER TO...OR
OVER...THE AIRFIELD WITHIN THE NEXT COUPLE HOURS AND A TEMPO GROUP
FOR THUNDER HAS BEEN ADDED. THIS MAY NEED TO BE EXTENDED...BUT WITH
WEAK WINDS AND FORCING...CONFIDENCE IN A TEMPO GROUP IS TOO LOW TO
INCLUDE AFTER 20 UTC. WINDS WILL GENERALLY BE LIGHT OUT OF THE SOUTH
THE REST OF THE DAY AND OVERNIGHT. HOWEVER...THUNDERSTORM OUTFLOW
BNDRYS WILL LIKELY RESULT IN STRONGER AND VARIABLE WINDS AT TIMES.

ELSEWHERE...TOWERING CU ARE DEVELOPING IN THE VCNTY OF KAVL AND
KHKY...AND VCTS HAS BEEN ADDED TO THESE SITES FOR THE REMAINDER OF
THE AFTN. THE UPSTATE IS CLEAR AND THE CHANCES FOR CONVECTION LOOK
LESS CERTAIN. HOWEVER...OUTFLOW BNDRYS MAY KICK OFF STORMS LATER
TODAY...ESPECIALLY OVER THE WEST...AND VCTS HAS BEEN ADDED TO KAND
LATER IN THE AFTN. KAVL MAY SEE A BRIEF PERIOD OF LOW CIGS OR FOG
AGAIN TONIGHT. IF IT DOESN/T RAIN AT THE AIRFIELD THEY PROBABLY
WON/T SEE ANYTHING...BUT IF IT DOES A LONGER PERIOD OF RESTRICTIONS
IS LIKELY AS THE FOG SETS UP.

OUTLOOK...ISLD/SCT AFTN-EVE TSTMS ACROSS THE AREA EACH DAY. MTN VLYS
WILL SEE BEST CHANCE OF MORNING LOW CLOUDS/FOG.

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...JAT/MCAVOY
SHORT TERM...PM
LONG TERM...PM
AVIATION...MCAVOY

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
150 PM EDT THU AUG 2 2012

GAZ010-017-018-026-028-029-NCZ033-035>037-048>053-056>059-062>065-
068>072-082-501>510-SCZ001>014-019-031800-
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-
150 PM EDT THU AUG 2 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.

ISOLATED TO WIDELY SCATTERED THUNDERSTORMS WILL DEVELOP ACROSS
THE AREA THIS AFTERNOON. ISOLATED SEVERE THUNDERSTORMS WILL BE
POSSIBLE...WITH LOCALLY DAMAGING WINDS AND LARGE HAIL BEING THE
PRIMARY THREATS. FREQUENT CLOUD TO GROUND LIGHTNING AND LOCALLY
HEAVY RAINFALL CAN OCCUR WITH ANY THUNDERSTORM. THE BEST CHANCE
FOR SEVERE STORMS WILL BE ACROSS THE FOOTHILLS AND PIEDMONT OF
WESTERN NORTH CAROLINA.

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

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

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

MCAVOY

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
328 PM EDT THU AUG 2 2012

NCZ064-022015-
TRANSYLVANIA-
328 PM EDT THU AUG 2 2012

...A STRONG THUNDERSTORM WILL AFFECT EASTERN TRANSYLVANIA COUNTY
THROUGH 415 PM EDT...

AT 324 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM NEAR BREVARD...MOVING SOUTHEAST AT 10 MPH.

DIME SIZE HAIL...AND WIND GUSTS UP TO 40 MPH ARE EXPECTED WITH THIS
STORM.

LAT...LON 3517 8259 3515 8259 3512 8267 3513 8268
      3511 8269 3510 8272 3529 8283 3533 8271

KRENTZ

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
343 PM EDT THU AUG 02 2012

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

0156 PM     TSTM WND DMG     MARION                  35.68N 82.01W
08/02/2012                   MCDOWELL           NC   EMERGENCY MNGR

            TREES DOWN ON W HENDERSON ST IN MARION. TIME ESTIMATED BY
            RADAR.

&&

MOORE

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
349 PM EDT THU AUG 02 2012

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

0230 PM     HAIL             SUGAR HILL              35.58N 82.04W
08/02/2012  E0.75 INCH       MCDOWELL           NC   PUBLIC

            DIME SIZED HAIL AROUND SUGAR HILL COMMUNITY.

&&

MOORE

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
538 PM EDT THU AUG 02 2012

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

0340 PM     TSTM WND DMG     1 SSW TUXEDO            35.21N 82.44W
08/02/2012                   HENDERSON          NC   911 CALL CENTER

            MULTIPLE TREES DOWN ON US HWY 25.

&&

JOH

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
551 PM EDT THU AUG 2 2012

NCZ082-022230-
UNION-
551 PM EDT THU AUG 2 2012

...A STRONG THUNDERSTORM WILL AFFECT EASTERN UNION COUNTY THROUGH 630
PM EDT...

AT 548 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM 5 MILES SOUTHWEST OF NEW SALEM...OR 9 MILES
NORTHEAST OF MONROE...MOVING SOUTHEAST AT 5 MPH.

* OTHER LOCATIONS AFFECTED INCLUDE BUT ARE NOT LIMITED TO
  UNIONVILLE...WINGATE...STURDIVANTS...NEW SALEM AND MARSHVILLE.

SMALL HAIL...WIND GUSTS OF 40 TO 50 MPH AND TORRENTIAL RAIN ARE
EXPECTED WITH THIS STORM.

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 3510 8028 3484 8031 3481 8034 3481 8038
      3506 8056 3518 8042 3518 8038 3513 8027

07

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
637 PM EDT THU AUG 2 2012

NCZ071-072-022315-
CABARRUS-MECKLENBURG-
637 PM EDT THU AUG 2 2012

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

AT 636 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM NEAR HARRISBURG...OR NEAR UNC CHARLOTTE...MOVING
SOUTHEAST AT 5 MPH.

THIS STORM WILL IMPACT LOCATIONS NEAR...
  HARRISBURG...
  HARRISBURG...

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

LAT...LON 3528 8046 3512 8069 3533 8085 3544 8068

KRENTZ