Special Weather Statement, NWS Greenville-Spartanburg, SC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
242 PM EDT THU JUN 12 2014

.SYNOPSIS...
AN UPPER LEVEL TROUGH IS CURRENTLY MAKING ITS WAY ACROSS THE AREA. A WEAK
COLD FRONT WILL APPROACH AND CROSS THE CWA FROM THE NORTHWEST AND SHOULD
STALL OUT TO OUR SOUTH OVER THE LATTER HALF OF THE WEEKEND. THIS
FRONT WILL THEN DISSIPATE AS A BERMUDA HIGH BUILDS IN FROM THE EAST
TOWARD THE BEGINNING OF THE WORK WEEK.

&&

.NEAR TERM /THROUGH FRIDAY/...
AS OF 235 PM EDT...RADAR COVERAGE REMAINS FAIRLY ROBUST THIS AFTN
AHEAD OF A MID/UPPER LEVEL SHORTWAVE MOVING NORTHEAST ACROSS THE
FORECAST AREA. DESPITE THE CLOUDS AHEAD OF THE WAVE...LAPS SBCAPE
VALUES ARE RUNNING 1500 TO 2500 J/KG AND SHOULD RISE...ESPECIALLY
EAST OF INTERSTATE 77...THROUGH LATE AFTN. THE BEST 850 TO 500 MB
DPVA WILL CROSS THE AREA FROM SW THROUGH 00Z. THIS WILL BE
COINCIDENT WITH THE BEST 850 MB THETA E PLUME ACROSS THE HEART OF
THE FORECAST AREA LATE THIS AFTERNOON. SLIGHTLY IMPROVING LATE DAY
SRLY FLOW AHEAD OF THE WAVE SHOULD HELP KEEP CELLS MOVING TO CURTAIL
SOME OF THE HEAVY RAINFALL THREAT. THE BEST OVERLAP OF
FORCING...INSTABILITY...AND A WEAK MID LEVEL DRY PUNCH SHOULD IMPACT
MAINLY INTERSTATE 77 AND POINTS EAST THROUGH EARLY EVENING. THIS IS
WHERE THE MARGINAL SEVERE TSTM THREAT WILL BE THE HIGHEST THROUGH
EARLY EVENING. POPS REMAIN HIGH LIKELY OR CATEGORICAL AHEAD OF THE
UPPER FEATURE IN THE NE HALF.

A BRIEF LULL IN UPPER FORCING IS EXPECTED TONIGHT BEFORE ANOTHER H5
SHORTWAVE CROSSES THE REGION FROM THE WEST FRI AFTN. HOWEVER...
CONTINUED LOW LEVEL MOISTURE AND NORTHWEST FLOW INTO THE NC MTNS
WILL KEEP ISOLD TO SCT UPSLOPE SHOWERS TRIGGERING ALONG THE TN
BORDER OVERNIGHT. IN RESPONSE TO THE UPPER WAVE FRI...A LOW LEVEL
SURFACE TO 850 MB REFLECTION MAY HELP TO FOCUS CONVERGENCE AND AID
COVERAGE THROUGH THE DAY...HOWEVER...THIS FEATURE APPEARS OVERDONE
ON THE NAM. WILL FEATURE MAINLY SOLID CHC POPS...WITH THE HIGHEST
VALUES OVER THE MTNS AND LOWEST CHANCES OVER THE PIEDMONT FRI AFTN.
AN APPROACHING SFC COLD FRONT SHOULD REMAIN WEST OF THE MTN CHAIN
THROUGH LATE FRI. TEMPS SHOULD REBOUND CLOSER TO CLIMO WITH LESS
PRECIP EARLY IN THE DAY.

&&

.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
AS OF 130 PM THURSDAY...A 500 MB SHORTWAVE TROF IS PROGGED TO CROSS
THE CWFA FRIDAY NIGHT...THEN STALL AND SHEAR OUT ACRS THE DEEP SOUTH
TO THE CAROLINAS...AS IT GETS TRAPPED UNDER A BUILDING UPPER RIDGE.
THERE WILL BE AN ACCOMPANYING WEAK SFC COLD FRONT...WHICH WILL PUSH
INTO THE CWFA FRIDAY NIGHT. THE BNDRY STALLS OUT ROUGHLY BELOW THE
MID LVL VORT LOBE FROM SRN AL...THRU CENTRAL GA AND THE SC
MIDLANDS...TO JUST SOUTH OF THE OUTER BANKS. GUIDANCE IN
DISAGREEMENT ON THE DEPICTION OF A LLVL WAVE DEVELOPING ALONG THE
FRONTAL BNDRY INVOF NRN GA...AND TAKING IT SLOWLY ACRS THE CAROLINAS
SATURDAY THRU SUNDAY. THE 12Z NAM AND CMC ARE MORE BULLISH WITH THIS
CIRCULATION...AND HAVE MORE QPF RESPONSE. THE GFS AND ECWMF ARE
NEBULOUS WITH ANY SFC REFLECTION OF THE WAVE...AND ARE OVERALL DRIER
ACRS THE CWFA. GIVEN THE WEAK MID AND UPR FORCING WITH BUILDING
RIDGE...I THINK THE NAM IS SUSPECT...AND WILL GO MORE IN LINE WITH
THE GFS/ECWMF SOLNS.

SO I EXPECT CONVECTION TO WANE WITH LOSS OF HEATING FRIDAY
NIGHT...DESPITE FRONT IN THE AREA. THEN ISOLD TO SCT DIURNAL
CONVECTION FOR SATURDAY AND SUNDAY...HIGHEST SOUTH. DEPENDING ON HOW
MUCH DRY AIR CAN FILTER IN FROM THE NORTH (AS SFC HIGH ENTERS THE
GREAT LAKES)...THE I-40 CORRIDOR MAY BE DRY SATURDAY. TEMPS WILL BE
NEAR NORMAL.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AS OF 1245 EDT PM THURSDAY...A BROAD UPPER RIDGE OF H5 HIGH WILL
PERSIST ACROSS MUCH OF THE SOUTHEAST U.S. SUN NIGHT INTO TUESDAY
BEFORE IT WEAKENS AND SHIFT EAST BY WED AS AN UPPER LOW PRESSURE
TROUGH DIGS INTO THE CENTRAL CONUS. THE TROUGH WILL THEN SLOWLY MOVE
EAST ACROSS THE EASTERN STATES WITH ITS TROUGH AXIS CROSSING THE CWA
BY EARLY FRIDAY.

AT THE SURFACE...A SUBTROPICAL HIGH CENTERED OVER THE WESTERN
ATLANTIC WILL CONTINUE TO RIDGE INTO THE FORECAST AREA SUN NIGHT
INTO WED. THE COMBINATION OF PERSISTENT MOIST S/SWLY FLOW AND
DIURNAL BUOYANCY WILL PROMOTE AFTERNOON SHOWERS AND THUNDERSTORMS ON
EACH DAY FAVORING IN THE MTNS ZONES. GIVEN WEAKLY SHEARED ALOFT AND
SHORT MBE VECTOR...WE CAN EXPECT RATHER SLOW MOVING CELLS GENERATING
HEAVY DOWNPOURS. A FEW SEVERE STORMS POSSIBLE OVER AREAS WITH BETTER
INSTABILITY. BY THURSDAY...HIGH WILL WEAKEN AND SHIFT EAST OF THE
AREA AS A COLD FRONT APPROACHES FROM THE NW. THE FRONT IS EXPECTED
TO CROSS THE CW LATE THU INTO EARLY FRI RESULTING IN BETTER COVERAGE
OF CONVECTION. WITH INCREASING WIND SHEAR AND MODERATE INSTABILITY
ALONG AND AHEAD OF THE FRONT...THERE IS THE POTENTIAL FOR SEVERE
WEATHER DURING THE FROPA. TEMPERATURES WILL START OUT NEAR NORMAL
MONDAY AND A GRADUAL WARMING TREND EXPECTED THRU DAY 7.

&&

.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
AT KCLT...ROBUST TSTM COVERAGE MOVING NE FROM THE SC UPSTATE SHOULD
REACH THE AIRFIELD IN THE ADVERTISED 19Z TO 23Z TEMPO PERIOD. SOME
GUSTS ARE LIKELY ALONG WITH TEMPO RESTRICTIONS IN LOWER CIGS/VSBY.
THERE IS SOME POTENTIAL FOR BRIEF REDUCTION TO IFR...BUT TSTMS OVER
UPSTREAM OBSERVING LOCATIONS DID NOT REACH IFR...SO WILL KEEP
RESTRICTIONS AT MVFR FOR NOW. EXPECT IMPROVEMENT THROUGH LATE
EVENING. THERE IS SOME POTENTIAL FOR OVERNIGHT RESTRICTIONS GIVEN
THE EXPECTED RAINFALL AT THE AIRFIELD...BUT MOS/MODELS ARE NOT
BULLISH ON THIS SO WILL JUST HINT AT SCATTERED LOW CLOUDS.
ANTICIPATE A SHIFT TO BRIEF LIGHT WESTERLY FLOW FRI MORNING BEFORE
WINDS BACK TO WSW OR SW AHEAD OF THE NEXT APPROACHING WAVE. WILL
HOLD OFF ON ANY FRI PRECIP MENTION UNTIL AFTER 18Z.

ELSEWHERE...THE PASSING UPPER WAVE WILL PRODUCE CONSIDERABLE
SHRA/TSTM COVERAGE ACROSS THE MTNS AND FOOTHILLS THROUGH LATE
AFTN/EARLY EVENING. THIS WILL CONTINUE TO BE HANDLED VIA TEMPO
GROUPS FOR TSRA WITH ASSOCIATED MVFR RESTRICTIONS. ANTICIPATE
IMPROVEMENT FROM THE SW INTO THE EVENING HOURS...WITH ANY LINGERING
NIGHTTIME VCSH ONLY NEAR KAVL IN NW UPSLOPE FLOW FROM THE TN BORDER.
WILL KEEP KAVL RESTRICTIONS AT MVFR FOR NOW GIVEN THE NW WINDS
OVERNIGHT...BUT FOG AND LOWER CLOUDS COULD FORM IN THE FRENCH BROAD
VALLEY IF THE WINDS SUFFICIENTLY SLACKEN. SHOWER COVERAGE WILL
RETURN FROM THE WEST THROUGH LATER FRI MORNING AS ANOTHER UPPER
SHORTWAVE APPROACHES. ANTICIPATE MAINLY SW SFC WINDS AT THE FOOTHILL
SITES...EXCEPT SRLY EARLY TURNING NW AT KAVL THIS EVENING.

OUTLOOK...MAINLY SCATTERED AFTERNOON AND EVENING THUNDERSTORMS WILL
CONTINUE INTO EARLY NEXT WEEK. THE BEST CHANCE FOR RESTRICTIONS
WILL BE IN TSRA AND ALSO IN THE MTN VALLEYS EACH MORNING WHERE LOW
CLOUDS AND FOG MAY FORM...AND IN AREAS WHERE RAIN FALLS THE DAY
BEFORE.

CONFIDENCE TABLE...

            18-24Z        00-06Z        06-12Z        12-18Z
KCLT       HIGH  99%     HIGH 100%     HIGH 100%     HIGH 100%
KGSP       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KAVL       MED   62%     HIGH  82%     MED   76%     HIGH  96%
KHKY       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KGMU       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KAND       MED   69%     HIGH  85%     HIGH 100%     HIGH 100%

THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE
HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE
FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)

WWW.WEATHER.GOV/GSP/AVIATION_TABLES

&&

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

&&

SYNOPSIS...STAARMANN
NEAR TERM...HG
SHORT TERM...ARK
LONG TERM...JOH
AVIATION...HG

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
1104 AM EDT THU JUN 12 2014

GAZ010-017-018-026-028-029-NCZ033-035>037-048>053-056>059-062>065-
068>072-082-501>510-SCZ001>014-019-131515-
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-
1104 AM EDT THU JUN 12 2014

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

.DAY ONE...TODAY AND TONIGHT.

NUMEROUS THUNDERSTORMS ARE EXPECTED TO DEVELOP ACROSS THE AREA
THIS AFTERNOON AND EVENING. THE THUNDERSTORMS WILL MOVE
SLOWLY...BRINGING A THREAT OF LOCALLY HEAVY RAINFALL TO AFFECTED
AREAS. ANY SERIES OF THUNDERSTORMS AFFECTING THE SAME LOCATION
COULD PRODUCE LOCALIZED FLASH FLOODING. THE PRIMARY THREAT WITH
THE THUNDERSTORMS WILL BE CLOUD TO GROUND LIGHTNING...BUT BRIEF
GUSTY WINDS AND HAIL ARE POSSIBLE. THE GREATEST THREAT OF DAMAGING
WIND GUSTS AND QUARTER SIZE HAIL WILL BE NEAR THE INTERSTATE 77
CORRIDOR IN THE PIEDMONT OF THE WESTERN CAROLINAS LATE THIS
AFTERNOON AND EARLY THIS EVENING.

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

..FRIDAY...NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.
..SATURDAY...NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.
..SUNDAY...NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.
..MONDAY...NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.
..TUESDAY...NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.
..WEDNESDAY...NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

SPOTTERS ARE ASKED TO RELAY ANY REPORTS OF FLOODING...DAMAGING
WINDS...OR LARGE HAIL TO THE NATIONAL WEATHER SERVICE.

GERAPETRITIS

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
212 PM EDT THU JUN 12 2014

NCZ068-SCZ008-121900-
CHEROKEE-CLEVELAND-
212 PM EDT THU JUN 12 2014

...A STRONG THUNDERSTORM WILL AFFECT NORTHWESTERN CHEROKEE AND
SOUTHERN CLEVELAND COUNTIES THROUGH 300 PM EDT...

AT 210 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM 5 MILES NORTHEAST OF COWPENS NATIONAL
BATTLEFIELD...OR 8 MILES NORTHWEST OF GAFFNEY...MOVING NORTHEAST AT
15 MPH.

THIS STORM WILL IMPACT LOCATIONS NEAR...
  BOILING SPRINGS NC...
  SHELBY...

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

THE COMBINATION OF GUSTY WINDS AND WET SOIL CONDITIONS WILL CAUSE
SCATTERED TREES AND POWER LINES TO FALL. SEEK SHELTER INSIDE AN
INTERIOR ROOM.

LAT...LON 3519 8139 3503 8177 3518 8182 3518 8177
      3523 8176 3527 8174 3542 8154

JOH

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
257 PM EDT THU JUN 12 2014

NCZ036-056-069-121945-
CATAWBA-IREDELL-LINCOLN-
257 PM EDT THU JUN 12 2014

...A STRONG THUNDERSTORM WILL AFFECT EASTERN LINCOLN...SOUTHWESTERN
IREDELL AND SOUTHEASTERN CATAWBA COUNTIES THROUGH 345 PM EDT...

AT 254 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM NEAR BOGER CITY...OR NEAR LINCOLNTON...MOVING
NORTHEAST AT 10 MPH.

THIS STORM WILL IMPACT LOCATIONS NEAR...
  IRON STATION...
  MAIDEN...
  DENVER...

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

THE COMBINATION OF GUSTY WINDS AND WET SOIL CONDITIONS WILL CAUSE
SCATTERED TREES AND POWER LINES TO FALL. SEEK SHELTER INSIDE AN
INTERIOR ROOM.

LAT...LON 3554 8080 3551 8088 3552 8090 3548 8095
      3541 8114 3541 8127 3552 8135 3577 8098

JOH

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
308 PM EDT THU JUN 12 2014

NCZ068-070-SCZ008-009-122015-
CHEROKEE-CLEVELAND-GASTON-YORK-
308 PM EDT THU JUN 12 2014

...A STRONG THUNDERSTORM WILL AFFECT NORTHWESTERN YORK...NORTHEASTERN
CHEROKEE...GASTON AND SOUTHEASTERN CLEVELAND COUNTIES THROUGH 415 PM
EDT...

AT 306 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM 5 MILES NORTHEAST OF BLACKSBURG...OR 10 MILES
SOUTHEAST OF SHELBY...MOVING NORTHEAST AT 10 MPH.

THIS STORM WILL IMPACT LOCATIONS NEAR...
  KINGS MOUNTAIN...
  CROWDERS MOUNTAIN STATE PARK...
  BESSEMER CITY...

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

PLEASE REPORT DAMAGING WINDS...HAIL...OR FLOODING TO THE NATIONAL
WEATHER SERVICE GREENVILLE SPARTANBURG BY CALLING TOLL FREE...1...
800...2 6 7...8 1 0 1...OR BY POSTING ON OUR FACEBOOK PAGE...OR TWEET
IT USING HASHTAG NWSGSP. YOUR MESSAGE SHOULD DESCRIBE THE EVENT AND
SPECIFIC LOCATION WHERE IT OCCURRED.

LAT...LON 3516 8102 3504 8146 3518 8160 3542 8131
      3541 8127

CDG