Hail and Damaging Wind in South Carolina, April 26, 2012

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
1156 AM EDT THU APR 26 2012

.SYNOPSIS...
A COLD FRONT WILL APPROACH THE AREA FROM THE NORTH RESULTING IN
UNSETTLED WEATHER. THIS COLD FRONT IS EXPECTED TO BECOME
STATIONARY FROM WEST TO EAST ACROSS OUR AREA FRIDAY AND SATURDAY.
THE FRONT WILL MOVE OFF TO THE SOUTH ON SUNDAY AS A CANADIAN HIGH
BUILDS OVER THE REGION. THEN THE HIGH WILL LINGER THROUGH THE EARLY
PART OF NEXT WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 1130 AM...THE MCS HAS FINALLY WEAKENED BELOW SEVERE LEVELS.
SOME NEW CONVECTION HAS BEEN TRYING TO FIRE ALONG A SUBTLE BNDRY
WITHIN THE MCV ACRS THE SRN NC MTNS. BUT THIS ACTIVITY HAS NOT BEEN
TOO STRONG. SO HAVE CANCELLED THE REMAINDER OF THE WATCH.

FOR THIS AFTN AND EVENING...VERY UNSTABLE AIR EXISTS AHEAD OF AN
APPROACHING COLD FRONT IN KY/TN. NUMEROUS TSTMS ARE EXPECTED TO
DEVELOP ALONG AND AHEAD OF THE FRONT THIS AFTN...WITH ACTIVITY
LIKELY AFFECTING THE NC MTNS BY LATE AFTN. THE CURRENT POP/WX TRENDS
STILL LOOK GOOD. WE ARE UNDER A SLIGHT RISK ACRS THE ENTIRE AREA FOR
THIS ACTIVITY...WHICH WILL LIKELY CONTINUE TO ROLL OFF THE MTNS INTO
THE PIEDMONT THIS EVENING.

PREVIOUS DISCUSSION...
THROUGH THE EVENING HOURS...THE SW TO NE FRONT MAY PUSH EAST OVER
THE FOOTHILLS AND PIEDMONT. FORECAST SOUNDINGS ACROSS THE CWA THIS
MORNING INDICATE A SIGNIFICANT H8 INVERSION. THIS INVERSION SHOULD
KEEP THE FOOTHILLS AND PIEDMONT CAPPED THROUGH MUCH OF THE DAY.
ACROSS THE MTNS...THE VALUES OF CIN ASSOCIATED WITH THE INVERSION IS
LESS...AND THE POTENTIAL FOR UPSTREAM CONVECTION TRACKING ACROSS THE
MTNS IS CERTAINLY POSSIBLE. I WILL KEEP CHC POPS OVER THE MTNS AND
SCHC OR LESS POPS EAST THROUGH 20Z. INTO THE EARLY EVENING
HOURS...THE APPROACH OF THE COLD FRONT WILL WEAKEN THE INVERSION AND
CONVECTION SHOULD GRADUALLY DEVELOP ALONG AND AHEAD OF THE FRONT. I
WILL INCREASE POPS TO LIKELY ACROSS THE TN BORDER COUNTIES AND
INDICATE SCT POPS EAST. FORECAST SOUNDINGS ACROSS THE MTNS INDICATE
THAT LLVL HELICITY WILL INCREASE TO AROUND 200 M2/S2...EHI ABOVE
2...AND SWEAT CLOSE TO 400. THE SHEAR COMBINED WITH SFC BASED CAPES
AROUND 2K J/KG AND WBZ AROUND 7.5 KFT SHOULD FAVOR THE DEVELOPMENT
OF SVR TS...ESPECIALLY ALONG THE TN LINE. SPC OUTLOOKS THIS AREA
WITH A SLIGHT RISK...HIGHLIGHTING THE POSSIBILITY OF SVR HAIL AND
WIND. WE WILL CONTINUE TO MENTION THE THREAT OF SVR TSRA ACROSS THE
NC MTNS IN THE HWO.

TONIGHT...CONVECTION WILL GRADUALLY ASHE OUT AROUND
MIDNIGHT...LIKELY LEAVING ISO SHRA AND TSRA NEAR THE GA/SC/NC
INTERSECTION INTO THE EARLY MORNING HOURS. NAM AND GFS INDICATE THAT
COOLER THICKNESSES WILL SLOWLY PUSH SOUTH ACROSS THE REGION
OVERNIGHT. USING A BLEND OF MOS...LOW TEMPERATURES ARE EXPECTED TO
RANGE FROM THE L50S ACROSS THE MTNS TO NEAR 60 ACROSS THE UPPER
SAVANNAH RIVER VALLEY.

&&

.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 330 AM THURSDAY...THE SHORT TERM FORECAST PICKS UP AT 12Z ON
FRIDAY WITH THE EASTERN CONUS UPPER TROF SLOWLY LIFTING NE AND THE
SOUTHERN STREAM BECOMES FAIRLY ZONAL. A WEAK UPPER RIDGING WILL
BUILD INTO THE SOUTHEAST U.S. SATURDAY AND ANOTHER UPPER TROF OVER
QUEBEC DIGS SOUTH BY EARLY SUNDAY.

AT THE SURFACE...A LOW PRESSURE WILL MOVE OFF THE NEW ENGLAND COAST
THURSDAY NIGHT/EARLY FRIDAY...AND DRAG A COLD FRONT SOUTHWARD INTO
OUR AREA. THE LATEST MODELS CONTINUE TO INDICATE THAT THE FRONT
BECOMES STATIONARY INVOF THE SOUTHERN EDGE OF THE CWA BY 12Z FRIDAY.
THEN THE FRONT WILL LIFT BACK NORTHWARD BY FRIDAY AFTERNOON. THE
LATEST MODEL SOUNDINGS HAVE TRENDED WEAKER WIND SHEAR AND LESS CAPE
VALUES THAN THE PREVIOUS RUNS. NEVERTHELESS...WITH SOME DEGREE OF
CONVERGENCE AND WEAK DIURNAL INSTABILITY...WE COULD SEE A
DEVELOPMENT OF SHOWERS AND THUNDERSTORMS ALONG THE FRONTAL BOUNDARY.
A MODEL BLEND FOR POPS RESULTS IN SOLID CHANCE POP WORKING FROM SW
TO NE DURING THE DAY AND INTO FRIDAY EVENING. THE FRONT WILL LIFT
NORTH OF THE AREA SATURDAY AS THE SUBTROPICAL HIGH BUILDS OVER THE
SOUTHEAST U.S. THE FRONT WILL REMAIN JUST TO OUR NORTH KEEPING OUR
WEATHER MOSTLY DRY AND WARMER TEMPS.

&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 230 AM THURSDAY...THE MEDIUM RANGE FORECAST PICKS UP AT 12Z ON
SUNDAY WITH WEAK UPPER RIDGING OVER THE CAROLINAS AND AN UPPER TROF
PERSISTING OVER THE NORTHEASTERN STATES. HEIGHTS BEGIN TO RISE
MONDAY AS THE UPPER TROF ROTATES OFF THE NEW ENGLAND COAST AND UPPER
RIDGING BUILDS INTO THE SOUTHEAST U.S. BY EARLY NEXT WEEK.

AT THE SURFACE...BOTH THE HPC AND THE GFS INDICATE THAT CANADIAN
SURFACE HIGH OVER THE GREAT LAKES AND NORTHEAST STATES WILL PUSH A
BACKDOOR COLD FRONT SOUTH ACROSS OUR FORECAST AREA ON SUNDAY. IN THE
WAKE OF THE FRONTAL PASSAGE...COLD AIR DAMMING IS EXPECTED FOR
SUNDAY NIGHT AND MONDAY. WITH DECENT MOISTURE AND WEAK LLVL
FORCING...HAVE MENTIONED SLIGHT CHANCE POP OVER THE PIEDMONT AND
SOLID CHANCE FOR NC MOUNTAINS AND FOOTHILLS. THE CONTINENTAL HIGH
BECOMES SUBTROPICAL HIGH AND REMAINS OVER THE SOUTHEAST U.S. TUE/WED
KEEPING A FRONTAL SYSTEM WELL TO OUR NORTH DURING THE PERIOD.
HOWEVER...WE CANNOT RULE OUT THE POSSIBILITY OF AFTERNOON SHOWERS
AND THUNDERSTORMS TUE/WED DUE TO INCREASING MOIST SOUTHERLY FLOW AND
DIURNAL INSTABILITY. DAYTIME TEMPS WILL BE A FEW DEGREES BELOW
NORMAL MON/TUE...THEN BACK ABOVE NORMAL WEDNESDAY.

&&

.AVIATION /16Z THURSDAY THROUGH MONDAY/...
AT KCLT...WINDS WILL REMAIN SSW AS A WARM FRONT MOVES NORTH. SW
WINDS ACROSS THE TERMINAL THIS MORNING WILL GRADUALLY STRENGTHEN
FROM THE PRE DAWN HOURS ON. A 4 TO 6 MB PRESSURE GRADIENT MAY
DEVELOP BY MID MORNING AS THE CENTER OF THE CLIPPER LOW MOVES OVER
THE OHIO RIVER VALLEY. MIXING TO 4 TO 5 KFT SHOULD RESULT IN GUSTY
SW WINDS FROM 14Z THROUGH SUNSET...GUSTING TO 20 TO 25 KTS. A COLD
FRONT ASSOCIATED WITH THE CLIPPER WILL PUSH NW TO SE ACROSS THE
REGION DURING THE LATE AFTERNOON TO EARLY EVENING HOURS. SHRA AND
TSRA SHOULD DEVELOP ALONG AND AHEAD OF THE FRONT...COVERAGE APPEAR
TOO LITTLE AT THIS POINT TO ADD TO THE TAF. WINDS SHOULD DECOUPLE
AND VEER NW AFTER 0Z.

ELSEWHERE...FOG AND LOW CLOUDS WILL REMAIN OVER KHKY THROUGH
13Z...THEN THE WARM FRONT SHOULD LIFT NORTH. SW WINDS ACROSS THE
TERMINAL THIS MORNING WILL GRADUALLY STRENGTHEN FROM THE PRE DAWN
HOURS ON. A BAND OF SHRA/TSRA MAY REACH KAVL AROUND 14Z. A 4 TO 6 MB
PRESSURE GRADIENT MAY DEVELOP BY MID MORNING AS THE CENTER OF THE
CLIPPER LOW MOVES OVER THE OHIO RIVER VALLEY. MIXING TO 4 TO 5 KFT
SHOULD RESULT IN GUSTY SW WINDS FROM 14Z THROUGH SUNSET...GUSTING TO
20 TO 25 KTS...A LITTLE STRONGER OVER THE SC UPSTATE. A COLD FRONT
ASSOCIATED WITH THE CLIPPER WILL PUSH NW TO SE ACROSS THE REGION
DURING THE LATE AFTERNOON TO EARLY EVENING HOURS. SHRA AND TSRA
SHOULD DEVELOP ALONG AND AHEAD OF THE FRONT. WINDS SHOULD DECOUPLE
AND VEER NW AFTER 0Z.

OUTLOOK...A COLD FRONT WILL APPROACH FROM THE NORTH THROUGH FRIDAY.
MAINLY PM SHOWERS/THUNDERSTORMS AND MORE WIDESPREAD RESTRICTIONS
WILL BE POSSIBLE LATE IN THE WEEK AS THE FRONT DIPS FARTHER SOUTH
INTO THE AREA.

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...JOH
NEAR TERM...ARK/NED
SHORT TERM...JOH
LONG TERM...JOH
AVIATION...NED

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
1149 AM EDT THU APR 26 2012

NCZ033-048>053-058-059-062>065-501-503-505-507-509-271600-
AVERY-MADISON-YANCEY-MITCHELL-SWAIN-HAYWOOD-BUNCOMBE-GRAHAM-
NORTHERN JACKSON-MACON-SOUTHERN JACKSON-TRANSYLVANIA-HENDERSON-
CALDWELL MOUNTAINS-BURKE MOUNTAINS-MCDOWELL MOUNTAINS-
RUTHERFORD MOUNTAINS-POLK MOUNTAINS-
1149 AM EDT THU APR 26 2012

THIS HAZARDOUS WEATHER OUTLOOK IS FOR WESTERN NORTH CAROLINA.

.DAY ONE...THIS AFTERNOON AND TONIGHT.

A COLD FRONT MAY BRING ANOTHER ROUND OF SEVERE WEATHER TO THE
NORTH CAROLINA MOUNTAINS LATE THIS AFTERNOON AND EVENING. THE
ENVIRONMENT ALONG AND AHEAD OF THE FRONT WILL SUPPORT CLUSTERS OR
LINES OF THUNDERSTORMS TO DEVELOP ACROSS EASTERN KENTUCKY AND
TENNESSEE. THESE STORMS WILL LIKELY TRACK EAST TO SOUTHEAST
REACHING THE NORTH CAROLINA MOUNTAINS LATE THIS AFTERNOON AND
EVENING. DAMAGING WIND GUSTS AND LARGE HAIL WILL BE POSSIBLE WITH
THESE STORMS.

.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...TORNADOES OR FLASH FLOODING TO OUR OFFICE.

GAZ010-017-018-026-028-029-NCZ035>037-056-057-068>072-082-502-504-
506-508-510-SCZ001>014-019-271600-
RABUN-HABERSHAM-STEPHENS-FRANKLIN-HART-ELBERT-ALEXANDER-IREDELL-
DAVIE-CATAWBA-ROWAN-CLEVELAND-LINCOLN-GASTON-MECKLENBURG-CABARRUS-
UNION NC-GREATER CALDWELL-GREATER BURKE-EASTERN MCDOWELL-
GREATER RUTHERFORD-EASTERN POLK-OCONEE MOUNTAINS-PICKENS MOUNTAINS-
GREENVILLE MOUNTAINS-GREATER OCONEE-GREATER PICKENS-
GREATER GREENVILLE-SPARTANBURG-CHEROKEE-YORK-ANDERSON-ABBEVILLE-
LAURENS-UNION SC-CHESTER-GREENWOOD-
1149 AM EDT THU APR 26 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.

SCATTERED THUNDERSTORMS ARE FORECAST TO DEVELOP ACROSS THE
FOOTHILLS AND PIEDMONT LATE THIS AFTERNOON AND EVENING. A FEW OF
THESE STORMS COULD PRODUCE QUARTER SIZED HAIL AND DAMAGING WIND
GUSTS.

.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...TORNADOES OR FLASH FLOODING TO OUR OFFICE.

ARK

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
1036 AM EDT THU APR 26 2012

GAZ026-028-029-SCZ006-010-011-019-261515-
ABBEVILLE-ANDERSON-ELBERT-FRANKLIN-GREATER GREENVILLE-GREENWOOD-HART-
1036 AM EDT THU APR 26 2012

...STRONG THUNDERSTORMS WILL AFFECT ABBEVILLE...ELBERT...FRANKLIN...
GREENWOOD...HART...SOUTHERN ANDERSON AND SOUTHERN GREENVILLE COUNTIES
THROUGH 1115 AM EDT...

AT 1036 AM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
STRONG THUNDERSTORMS ALONG A LINE EXTENDING FROM 4 MILES SOUTH OF
FORK SHOALS TO FAIR PLAY...MOVING SOUTHEAST AT 45 MPH.

THESE STORMS WILL BE NEAR...
  VANNA...
  BOWMAN...
  SECESSION LAKE...
  RUCKERSVILLE...
  LAKE RUSSELL...
  FORTSONIA...

PEA SIZE HAIL AND WIND GUSTS OF 30 TO 40 MPH ARE EXPECTED WITH THESE
STORMS.

LAT...LON 3401 8224 3397 8231 3406 8234 3407 8248
      3401 8259 3396 8256 3398 8286 3417 8311
      3423 8308 3426 8313 3422 8336 3446 8340
      3451 8308 3447 8299 3452 8294 3459 8224
      3447 8231 3420 8192 3413 8187 3395 8202

HG

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
1057 AM EDT THU APR 26 2012

SCZ012>014-261530-
CHESTER-LAURENS-UNION-
1057 AM EDT THU APR 26 2012

...STRONG THUNDERSTORMS WILL AFFECT CHESTER...LAURENS AND SOUTHERN
UNION COUNTIES THROUGH 1130 AM EDT...

AT 1056 AM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
STRONG THUNDERSTORMS ALONG A LINE EXTENDING FROM 3 MILES SOUTH OF
LOWRYS TO 4 MILES EAST OF HONEA PATH...MOVING SOUTHEAST AT 50
MPH.

THESE THUNDERSTORMS HAVE A HISTORY OF PRODUCING WIND GUSTS OF 30 TO
40 MPH AS WELL AS PEAS TO DIME SIZE HAIL. FREQUENT LIGHTNING CAN
ALSO BE EXPECTED WITH THE PASSAGE OF THE LINE. TAKE SHELTER AS THIS
LINE APPROACHES YOUR AREA.

LAT...LON 3433 8217 3447 8231 3460 8189 3458 8187
      3462 8185 3483 8114 3481 8088 3477 8086
      3469 8085 3462 8089 3456 8087 3454 8093
      3456 8141 3450 8141 3444 8154 3452 8164
      3436 8178 3430 8189 3421 8194

HG

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
1101 AM EDT THU APR 26 2012

GAZ026-028-029-SCZ010-011-019-261545-
ABBEVILLE-ANDERSON-ELBERT-FRANKLIN-GREENWOOD-HART-
1101 AM EDT THU APR 26 2012

...STRONG THUNDERSTORMS WILL AFFECT ABBEVILLE...ELBERT...FRANKLIN...
GREENWOOD...HART AND SOUTHERN ANDERSON COUNTIES THROUGH 1145 AM
EDT...

AT 1100 AM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
STRONG THUNDERSTORMS ALONG A LINE EXTENDING FROM HONEA PATH TO
CARNESVILLE...MOVING SOUTHEAST AT 40 MPH.

THESE THUNDERSTORMS HAVE A HISTORY OF PRODUCING WIND GUSTS OF 30 TO
40 MPH AS WELL AS PEA TO DIME SIZE HAIL. FREQUENT LIGHTNING WILL
ALSO OCCUR WITH THE PASSAGE OF THE LINE. TAKE SHELTER INDOORS AS
THIS LINE APPROACHES YOUR AREA.

LAT...LON 3401 8224 3397 8231 3406 8234 3407 8248
      3401 8259 3396 8256 3398 8286 3417 8311
      3423 8308 3426 8313 3423 8317 3426 8331
      3422 8335 3439 8339 3441 8339 3450 8233
      3433 8217 3420 8192 3412 8188 3395 8202

HG

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
1105 AM EDT THU APR 26 2012

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

1103 AM     HAIL             FAIR PLAY               34.51N 82.99W
04/26/2012  E0.50 INCH       OCONEE             SC   TRAINED SPOTTER

&&

LG

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
1115 AM EDT THU APR 26 2012

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

0854 AM     TSTM WND DMG     1 W OLD FORT            35.63N 82.19W
04/26/2012                   MCDOWELL           NC   FIRE DEPT/RESCUE

            ONE TREE DOWN ON HIGHWAY 80

&&

LG

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
1141 AM EDT THU APR 26 2012

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

0854 AM     TSTM WND DMG     2 SSW OLD FORT          35.60N 82.19W
04/26/2012                   MCDOWELL           NC   FIRE DEPT/RESCUE

            POWER POLE DOWN SSW OF OLD FORT

&&

LG