Severe Thunderstorm Warning 31, NWS Greenville-Spartanburg, SC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
318 PM EDT SAT MAY 10 2014

.SYNOPSIS...
BERMUDA HIGH PRESSURE WILL STRENGTHEN OVER THE SOUTHEAST SUNDAY
THROUGH TUESDAY. A STRONG LOW PRESSURE SYSTEM MOVING EAST FROM THE
PLAINS WILL BRING A COLD FRONT TO THE AREA BY THURSDAY...WITH A
SIGNIFICANT COOLDOWN EXPECTED LATE WEEK INTO THE WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
AS OF 230 PM...AS EXPECTED...CONVECTION HAS EXPLODED ACRS THE
PIEDMONT FROM NE GA INTO THE SW NC PIEDMONT...WHERE CAPE VALUES OF
1500-2000 J/KG WERE ANALYZED BY THE LAPS. STORMS ARE REACHING
MARGINAL CORE HEIGHTS (55 DBZ NEAR 22 KFT) WHICH MAY BE ENUF TO
PRODUCE 1" HAIL AND DAMAGING WIND GUSTS. OVERALL...STILL EXPECT
MAINLY SUB-SEVERE STORMS AND SHOWERS WITH BRIEF TORRENTIAL DOWNPOURS
AND GUSTY WINDS. THE CELLS SEEM TO HAVE ENUF MOVEMENT TO LIMIT HEAVY
RAIN/FLOODING THREAT. CONVECTION SHUD WANE FAIRLY QUICKLY WITH LOSS
OF HEATING...AS ATMOSPHERE WILL BE WORKED OVER AND AN UPPER
SHORTWAVE WILL EXIT TO THE EAST.

OVERNIGHT...THE NAM AND GFS FCST SNDGS SHOW PLENTY OF MID LVL AND
UPR LVL DRYING BEHIND A PASSING SHORTWAVE...WHILE THE LLVLS REMAIN
MOIST. A COLD FRONT APPEARS TO WASH OUT TO THE NORTH OF THE
CWFA...SO WINDS WILL REMAIN LIGHT OR CALM AS WELL. GUIDANCE MAY BE
UNDERDONE ON FOG POTENTIAL. CERTAINLY IF SKIES CAN CLEAR EARLY
ENUF...THERE MAY BE AREAS OF FOG...POSSIBLY DENSE. TEMPS ARE FCST TO
FALL INTO THE 50S MTNS AND LWR 60S...WHICH IS WELL BELOW THE CURRENT
DWPTS.

SUNDAY...THE 500 MB HIGH BEGINS TO REASSERT ITSELF ACRS THE
SOUTHEAST STATES...WITH A BERMUDA HIGH TO THE EAST. OUR AREA SEEMS
TO BE IN BETWEEN THE BETTER MOISTURE TO SOUTH AND STRONGER
SUBSIDENCE AND DRIER AIR TO THE NORTH. THE NAM HAS PLENTY OF BL
MOISTURE ACRS THE AREA WITH A LIGHT SE FLOW. WHILE THE GFS IS ON
AVERAGE ABOUT 5 DEG LOWER OF DWPTS AND HAS A WEAK SW/W FLOW. THIS
RESULTS IN MORE CAPE ON THE NAM...ESP ACRS THE PIEDMONT.
HOWEVER...EVEN WITH THE INCREASED CAPE...THE NAM DOES NOT LOOK TOO
EXCITED ABOUT CONVECTION. I OPTED TO ONLY MAKE MINOR TWEAKS TO THE
POPS INHERITED FROM LAST NIGHT. STILL EXPECT AT LEAST ISOLD SHWRS
AND TSTMS...PERHAPS A LITTLE BETTER COVERAGE IN THE MTNS WHERE
DIFFERENTIAL MTN HEATING SHUD PROVIDE BEST TRIGGERING. TEMPS ARE
EXPECTED TO REBOUND INTO THE UPR 70S TO LWR 80S...AND MID 80S ACRS
THE PIEDMONT.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/...
AS OF 300 PM EDT SATURDAY...A PROMINENT 588 DM H5 RIDGE WILL BE IN
PLACE ACROSS THE SOUTHEAST ON MONDAY...WITH A HIGH AMPLITUDE PATTERN
FIRMLY IN PLACE BETWEEN A DEEP CENTRAL CONUS TROUGH AND EAST COAST
RIDGE BY TUE. DESPITE THE RIDGING AND RESULTANT MID LEVEL
INVERSION...PERSISTENT LOW LEVEL SRLY UPSLOPE FLOW SHOULD PROVIDE
TRIGGERING ACROSS THE MTNS. WILL THUS FEATURE MAINLY SCATTERED
DIURNAL CONVECTION MON AND TUE AFTN...WITH A FOCUS IN THE MTNS.
EXPECT WARM TEMPS THROUGH THE PERIOD.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
AS OF 300 PM EDT SATURDAY...UPPER DIVERGENCE AND IMPROVING SRLY FLOW
WILL AID CONVECTIVE COVERAGE STARTING WED...AND A MORE NON DIURNAL
NATURE IS EXPECTED GIVEN THE APPROACHING HIGH AMPLITUDE TROUGH AND
ASSOCIATED SURFACE FRONT. THE DEEPEST FORCING AND MOISTURE SHOULD
ARRIVE THU AS A BROAD AREA OF STRONG Q VECTOR CONVERGENCE CROSSES
THE REGION...ESPECIALLY DURING THE AFTN/EVENING HOURS. THIS COULD
LEAD TO STRONG TO SEVERE CONVECTION...BUT THE TIMING REMAINS
SOMEWHAT UNCERTAIN. IN ADDITION...MOST OF THE MODELS STILL DEPICT A
TROPICAL FEATURE MOVING NWD FROM THE FL COASTAL WATERS TO THE
CAROLINA COASTAL WATERS THU. THIS SHOULD REMAIN EAST OF THE AREA.

THE DEEP ERN TROUGH WILL PERSIST FRI THROUGH SAT...BUT WITH DRIER
AIR AND COOLER TEMPERATURES ARRIVING. ADDITIONAL ENERGY ROUNDING THE
TROUGH WILL BE HARD TO TIME...BUT THE BEST CONSENSUS FOR THE NEXT
VORT LOBE AND ASSOC MOISTURE APPEARS ON SAT...AND THERE MAY BE SOME
LOW LEVEL WAVE FORMATION ALONG A BAROCLINIC ZONE. WILL FEATURE LOW
END CHC GIVEN THE STEEP LAPSE RATES UNDER THE TROUGH.

&&

.AVIATION /19Z SATURDAY THROUGH THURSDAY/...
AT KCLT...AS WITH THE 15Z AMD...EXPECT SHRA AND TSRA TO START
DEVELOPING AND/OR MOVING INTO THE CLT AREA WITHIN THE NEXT COUPLE
HOURS...WITH MAX COVERAGE EXPECTED TO BE IN THE 19-22Z TIME FRAME.
LIKE YESTERDAY...EXPECT BRIEF TORRENTIAL DOWNPOURS...LIGHTNING...AND
GUSTY WINDS WITH ANY STORMS THAT IMPACT THE TERMINAL DIRECTLY. FROM
THERE...COVERAGE SHUD WANE FAIRLY QUICKLY UPON SUNSET...AS INSTBY
WANES. GUIDANCE SHOWS PLENTY OF DRYING OF THE MID AND UPR LVLS
OVERNIGHT...BUT LINGERING LLVL MOISTURE. SO THERE MAY BE SOME PATCHY
FOG DEVELOPMENT. GUIDANCE IS NOT IN GOOD AGREEMENT ON VSBY
RESTRICTIONS AT KCLT. FOR NOW...WILL GO WITH A COUPLE HOURS OF MVFR
VSBY AROUND DAYBREAK. HIGH PRES BUILDS IN ON SUNDAY...SO EXPECTING
ONLY ISOLD CONVECTION ACRS THE PIEDMONT SUNDAY AFTN. WINDS WILL
FAVOR SW THRU THIS EVENING...EXCEPT VRB NEAR TS. THEN GOING CALM OR
LGT/VRB THIS EVENING THRU SUNDAY MORNING.

ELSEWHERE...AS EXPECTED...CONVECTION HAS REALLY STARTED TO TAKE OFF
ACRS THE UPSTATE. GIVEN THE CURRENT COVERAGE...WILL HAVE VCTS AND
TEMPO TSRA AT ALL THREE UPSTATE TAF SITES. CONVECTION SHUD START TO
DIMINISH AND HEAD EAST OF THE TERMINALS BY LATE AFTN/EARLY EVENING
GUSTY WINDS AND BRIEF MVFR OR EVEN IFR RESTRICTIONS CAN BE EXPECTED
WITH ANY DIRECT IMPACTS. THERE IS LESS INSTBY AT KAVL AND KHKY...SO
EXPECTING MAINLY SHRA THRU THE REST OF THE AFTN. THE MID AND UPR
LVLS WILL BEGIN TO DRY OUT THIS EVENING...BUT LLVL MOISTURE WILL
LINGER THRU THE OVERNIGHT. WINDS SHUD GO CALM OR LGT/VRB AT PRETTY
MUCH ALL TAF SITES. WITH THE MOIST BOUNDARY LAYER...THERE MAY BE
PATCHY FOG DEVELOPMENT. SO SOME VSBY RESTRICTIONS WERE ADDED TO ALL
TAF SITES LATE TONIGHT THRU DAYBREAK SUNDAY. THE BEST CHANCES FOR
FOG WILL BE IN THE WEST (KAVL AND KAND)...AS THEY WILL CLEAR
EARLIEST. VFR CONDITIONS ARE EXPECTED NOT LONG AFTER SUNRISE...WITH
MOSTLY CLEAR SKIES. HIGH PRES BUILDING IN SHUD LIMIT CONVECTION TO
MAINLY ISOLD IN THE PIEDMONT AND WIDELY SCATTERED IN THE MTNS SUNDAY
AFTN.

OUTLOOK...HIGH PRESSURE RETURNS SUNDAY AND MONDAY...BUT AFTERNOON
AND EVENING CONVECTION WILL BE POSSIBLE BOTH DAYS. WEDNESDAY AND
THURSDAY FEATURE A SLOW MOVING COLD FRONT...YIELDING A BETTER CHANCE
OF RESTRICTIONS IN PROLONGED PRECIPITATION.

CONFIDENCE TABLE...

            19-01Z        01-07Z        07-13Z        13-19Z
KCLT       HIGH 100%     HIGH 100%     HIGH  91%     HIGH 100%
KGSP       HIGH 100%     HIGH 100%     HIGH 100%     HIGH  96%
KAVL       HIGH 100%     HIGH  94%     HIGH  83%     HIGH  96%
KHKY       HIGH 100%     HIGH  94%     HIGH  80%     HIGH 100%
KGMU       HIGH 100%     HIGH 100%     HIGH 100%     HIGH  96%
KAND       HIGH 100%     HIGH 100%     HIGH  90%     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...HG
NEAR TERM...ARK
SHORT TERM...HG
LONG TERM...HG
AVIATION...ARK

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
546 AM EDT SAT MAY 10 2014

GAZ010-017-018-026-028-029-NCZ033-035>037-048>053-056>059-062>065-
068>072-082-501>510-SCZ001>014-019-111000-
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-
546 AM EDT SAT MAY 10 2014

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

.DAY ONE...TODAY AND TONIGHT.

SCATTERED THUNDERSTORMS WILL DEVELOP ACROSS THE WESTERN CAROLINAS
AND NORTHEAST GEORGIA AGAIN TODAY...MAINLY THIS AFTERNOON. THE
STRONGER THUNDERSTORMS MAY OCCUR OVER THE PIEDMONT OF THE
CAROLINAS. ONE OR TWO OF THE STORMS MAY GROW LARGE ENOUGH TO
PRODUCE DAMAGING WIND GUSTS AND LARGE HAIL. OTHERWISE...THE MOST
LIKELY THREATS ARE FREQUENT CLOUD TO GROUND LIGHTNING AND HEAVY
DOWNPOURS.

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

..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.
..THURSDAY...NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.
..FRIDAY...NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

NONE.

PM

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
143 PM EDT SAT MAY 10 2014

GAZ028-029-SCZ010-011-101830-
ABBEVILLE-ANDERSON-ELBERT-HART-
143 PM EDT SAT MAY 10 2014

...STRONG THUNDERSTORMS WILL AFFECT SOUTHWESTERN ANDERSON...WESTERN
ABBEVILLE...EASTERN HART AND ELBERT COUNTIES THROUGH 230 PM EDT...

AT 138 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
STRONG THUNDERSTORMS ALONG A LINE EXTENDING FROM 5 MILES SOUTH OF
BOWMAN TO ELBERTON...MOVING NORTHEAST AT 30 MPH.

THESE STORMS WILL IMPACT LOCATIONS NEAR...
  BOWMAN...
  RUCKERSVILLE...
  LAKE RUSSELL...
  HARTWELL...
  IVA...
  SECESSION LAKE...

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

GUSTY WINDS CAN BLOW DOWN TREES THAT ARE DEAD...OR THAT HAVE WEAKENED
ROOT SYSTEMS. OUTDOOR FURNITURE AND SIMILAR ITEMS CAN BE TOSSED
AROUND IF NOT ANCHORED. SEEK SHELTER INDOORS.

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 3413 8306 3416 8309 3457 8283 3435 8245
      3399 8285

JOH

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
146 PM EDT SAT MAY 10 2014

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

0145 PM     HAIL             MAULDIN                 34.79N  82.30W
05/10/2014  E0.50 INCH       GREENVILLE         SC   PUBLIC

            PUBLIC REPORT OF PEA TO HALF INCH HAIL ALONG BUTLER
            ROAD.

&&

HG

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
216 PM EDT SAT MAY 10 2014

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

0215 PM     HAIL             SIMPSONVILLE            34.73N  82.26W
05/10/2014  E0.75 INCH       GREENVILLE         SC   PUBLIC

            PUBLIC REPORT OF DIME SIZE HAIL.

&&

HG

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
222 PM EDT SAT MAY 10 2014

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

0218 PM     HAIL             SIMPSONVILLE            34.73N  82.26W
05/10/2014  E0.75 INCH       GREENVILLE         SC   TRAINED SPOTTER

            SPOTTER REPORT OF DIME SIZE HAIL ON SOUTH MAIN STREET.

&&

HG

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
222 PM EDT SAT MAY 10 2014

NCZ071-072-082-101900-
CABARRUS-MECKLENBURG-UNION-
222 PM EDT SAT MAY 10 2014

...A STRONG THUNDERSTORM WILL AFFECT NORTHWESTERN UNION...MECKLENBURG
AND SOUTH CENTRAL CABARRUS COUNTIES IN THE PIEDMONT OF NORTH CAROLINA
THROUGH 300 PM EDT...

AT 219 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM NEAR PINEVILLE...OR 9 MILES SOUTH OF CENTER CITY
CHARLOTTE...MOVING NORTHEAST AT 25 MPH.

THIS STORM WILL IMPACT LOCATIONS NEAR...
  SOUTHPARK MALL...
  FREEDOM PARK...
  MCALPINE CREEK PARK...
  EASTLAND MALL...
  MINT HILL...
  HIDDEN VALLEY...

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

GUSTY WINDS CAN BLOW DOWN TREES THAT ARE DEAD...OR THAT HAVE WEAKENED
ROOT SYSTEMS. OUTDOOR FURNITURE AND SIMILAR ITEMS CAN BE TOSSED
AROUND IF NOT ANCHORED. SEEK SHELTER INDOORS.

HEAVY RAINS MAY FLOOD AREAS WITH POOR DRAINAGE...SUCH AS DITCHES AND
UNDERPASSES. AVOID THESE AREAS AND DO NOT CROSS FLOODED ROADS. WATER
LEVELS OF SMALL STREAMS AND RIVERS MAY ALSO RISE RAPIDLY. SEEK HIGHER
GROUND IF THREATENED BY FLOOD WATERS.

LAT...LON 3498 8078 3504 8088 3511 8094 3509 8096
      3509 8097 3539 8081 3526 8048

JOH

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
247 PM EDT SAT MAY 10 2014

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

0225 PM     HAIL             SIMPSONVILLE            34.73N  82.26W
05/10/2014  E0.75 INCH       GREENVILLE         SC   PUBLIC

            REPORT OF DIME TO PENNY HAIL ROCKY CREEK AND GEORGIA
            ROADS.

&&

HG