Severe Thunderstorm Warning 178, NWS Greenville-Spartanburg, SC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
324 PM EDT SAT MAY 20 2006

.SHORT TERM /TONIGHT THROUGH TUESDAY/...
CONVECTION HAS BLOSSOMED RAPIDLY OVER THE SOUTHWEST CWFA IN
MODERATELY UNSTABLE ENVIRONMENT OVER THE AREA. LOW LEVEL WIND HAS
YET TO MAKE THE TURN TO A WESTERLY DIRECTION...SO MIXING WAS
MINIMIZED IN THE SOUTH DESPITE NEARLY FULL SUN AND LAPSE RATES HAVE
BECOME QUITE STEEP. WIND SHEAR STILL SUFFICIENT FOR SUPERCELLS
THROUGH 21Z OR SO...THEN FORECAST DATA SUGGESTS WEAKENING SHEAR BUT
STILL A HAIL THREAT. UPSTREAM...A CONVECTIVE COMPLEX HAS DEVELOPED
OVER SOUTHERN TENNESSEE...AHEAD OF A VORT CENTER. THIS COMPLEX
SHOULD OVERSPREAD THE FAR WESTERN MOUNTAINS...NORTHEAST GEORGIA AND
THE WESTERN HALF OF THE UPSTATE THROUGH THROUGH EARLY EVENING...THEN
PERHAPS TREK A BIT TO THE EAST. NAM AND GFS BOTH BREAK UP THE PRECIP
FIELD IN FAVORED-DOWNSLOPE LOCATIONS...THEN ORGANIZE ANOTHER
CONVECTIVE CLUSTER OVER THE EASTERN ZONES AS THE COLD FRONT FROM UP
NORTH SAGS SOUTH. WE WILL FEATURE HIGH CHANCE TO LIKELY POPS IN THE
SOUTH...TRENDING TO ISOLATED NORTH OF INTERSTATE 40.

UPPER AIR ANALYSIS THIS MORNING SHOWED A TROF UPSTREAM THAT IS
EXPECTED TO MOVE IN OUR DIRECTION OVERNIGHT AND SUNDAY. AT THE SAME
TIME...MODELS SUGGEST A SECONDARY FRONT OR SURFACE BOUNDARY WILL
BACK DOOR FROM THE MID ATLANTIC STATES AS ANOTHER LOBE OF DPVA
AFFECTS THE REGION WITH SHORTWAVE. AGAIN...IT APPEARS THE SOUTHWEST
MOUNTAINS...NORTHEAST GEORGIA AND THE UPSTATE WILL HAVE GREATEST
COVERAGE OF PRECIPITATION. AT THE SAME TIME...FRONT CURRENTLY
ATTEMPTING TO DROP SOUTH ACROSS THE REGION WILL BE STATIONARY JUST
TO OUR SOUTH. ANY OSCILLATION OF THE FEATURE BACK NORTHWARD COULD
RESULT IN SLIGHTLY BETTER COVERAGE OVER THE SOUTHERN CWFA. WE WILL
PLAN CHANCE POPS FOR THE AFOREMENTIONED AREAS...AND LIMIT TO
ISOLATED OR LESS FOR THE MORE NORTHERN AREAS...WHERE RETURN FLOW
MAY NOT BE AS GREAT.

ANOTHER REINFORCING COLD FRONT WILL MOVE SOUTHWARD INTO NORTH
CAROLINA SUNDAY NIGHT...AS DIVERGENCE IN THE RIGHT ENTRANCE REGION
OF THE UPPER JETLET CROSSES THE SOUTHERN APPALACHIANS. TIMING OF
H5 SHORTWAVES VARIES WIDELY FROM MODEL TO MODEL FOR THE SUN NIGHT
THROUGH MON PERIOD...BUT CONSENSUS BRINGS THE BEST UPPER SUPPORT
TO THE SRN APPALACHIANS AROUND 12Z MONDAY. THE COLD FRONT WILL
CONTINUE TO PROVIDE A FOCUSING MECHANISM FOR SCATTERED CONVECTION
AS IT MOVES SOUTH ACROSS THE REGION ON MONDAY...THEN SLIP SOUTH OF
THE AREA ON TUESDAY.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
AN UPPER LEVEL LOW PRES SYSTEM IS EXPECTED TO DEVELOP IN THE MIDWEST
ON THURSDAY...AND SWING SLOWLY THROUGH THE CENTRAL APPALACHIANS
THROUGH NEXT WEEKEND. PRECIPITATION CHANCES WILL RAMP UP ACCORDINGLY
THU THROUGH SAT...AS A SURFACE FRONT REMAINS STALLED ACROSS THE
REGION.

&&

.AVIATION...
DELAY OF SURFACE FRONT PUSHING SOUTH ACROSS THE AREA HAS RESULTED
IN SOUTH TO SOUTHWEST SURFACE WINDS IN THE FOOTHILLS AND PIEDMONT.
WIND SHOULD VEER TO MORE OF A WESTERLY DIRECTION AS THE FRONT SAGS
SOUTH PAST KHKY LATE THIS AFTERNOON...BUT MAY MAINTAIN SOME
SEMBLENCE OF SOUTHWEST CHARACTERISTICS AS SHORTWAVE ENERGY
APPROACHES FROM THE WEST. TSRA ORGANIZING NOW OFF TO THE WEST. WE
INCLUDED A TEMPO GROUP AT KAND FOR MVFR VISIBILITY RESTRICTIONS IN
THE 20Z TO 23Z TIME FRAME...WITH VCSH INCLUDED FROM LATE AFTERNOON
TO 00Z AT ALL OTHER SITES EXCEPT FOR KHKY. AFTER THIS EVENING...A
GENERAL LIGHT WEST WIND SHOULD DOMINATE. THERE WILL LIKELY BE A
PERIOD OF VARIABLE WIND DIRECTION WITH LIGHT SPEEDS LATE TONIGHT
THROUGH THE EARLY OUTLOOK PERIOD. THE FINAL HOURS OF THE OUTLOOK
PERIOD AGAIN FEATURE WEST WINDS AROUND 6 TO 8 KTS...WITH VFR
CEILINGS.

&&

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

SHORT TERM...HG/SAB
LONG TERM...HG
AVIATION...SAB

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
600 AM EDT SAT MAY 20 2006

GAZ010-017-018-026-028-029-NCZ033-035>037-048>053-056>059-062>065-
068>072-082-501>510-SCZ001>014-019-211000-
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-
600 AM EDT SAT MAY 20 2006

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

.DAY ONE...TODAY AND TONIGHT

SEVERE THUNDERSTORMS ARE POSSIBLE THIS AFTERNOON AND EVENING OVER
MUCH OF THE WESTERN CAROLINAS AND NORTHEAST GEORGIA...WITH THE
BEST CHANCE ALONG AND SOUTH OF A LINE FROM ASHEVILLE TO GREENVILLE
AND ROCK HILL.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY

THUNDERSTORMS WILL AGAIN BE POSSIBLE OVER THE WESTERN CAROLINAS
AND NORTHEAST GEORGIA WEDNESDAY AND THURSDAY. A FEW OF THESE COULD
PRODUCE DAMAGING WINDS AND LARGE HAIL.

.SPOTTER INFORMATION STATEMENT...
SPOTTER ACTIVATION MAY BE NEEDED THIS AFTERNOON AND EVENING.

MCAVOY

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
236 PM EDT SAT MAY 20 2006

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

0230 PM     HAIL             CLEMSON                 34.68N 82.81W
05/20/2006  E1.00 INCH       PICKENS            SC   TRAINED SPOTTER

            SPOTTER REPORTS NICKEL TO QUARTER SIZE HAIL

&&

HG

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
308 PM EDT SAT MAY 20 2006

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

0244 PM     HAIL             4 W ANDERSON            34.52N 82.72W
05/20/2006  E0.88 INCH       ANDERSON           SC   TRAINED SPOTTER

            NICKLE SIZE HAIL REPORTED BY SPOTTER 4 MILES WEST OF EXIT
            19 ON INTERSTATE 85.

0228 PM     HAIL             CLEMSON                 34.68N 82.81W
05/20/2006  E1.00 INCH       PICKENS            SC   TRAINED SPOTTER

            NICKLE TO QUARTER SIZE HAIL REPORTED BY SPOTTER.

0244 PM     HAIL             3 NE ANDERSON           34.55N 82.61W
05/20/2006  E1.75 INCH       ANDERSON           SC   TRAINED SPOTTER

            GOLF BALL SIZE HAIL REPORTED BY SPOTTER.

0246 PM     HAIL             ANDERSON                34.52N 82.65W
05/20/2006  E1.00 INCH       ANDERSON           SC   TRAINED SPOTTER

            QUARTER SIZE HAIL REPORTED BY SPOTTER.

0250 PM     HAIL             ANDERSON                34.52N 82.65W
05/20/2006  E0.75 INCH       ANDERSON           SC   TRAINED SPOTTER

            SPOTTER REPORTS PENNY SIZE HAIL.

0255 PM     HAIL             PELZER                  34.64N 82.46W
05/20/2006  E0.88 INCH       ANDERSON           SC   TRAINED SPOTTER

            SPOTTER REPORTS NICKLE SIZE HAIL.

&&

SBK

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
351 PM EDT SAT MAY 20 2006

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

0329 PM     HAIL             GROVER                  35.20N 81.48W
05/20/2006  U1.75 INCH       CLEVELAND          NC   PUBLIC

&&

LANE

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
401 PM EDT SAT MAY 20 2006

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

0250 PM     HAIL             ANDERSON                34.52N 82.65W
05/20/2006  E0.75 INCH       ANDERSON           SC   TRAINED SPOTTER

            DIME SIZED HAIL NEAR BELVIEW AVENUE IN ANDERSON

0332 PM     HAIL             N ENOREE                34.66N 81.97W
05/20/2006  E0.88 INCH       SPARTANBURG        SC   AMATEUR RADIO

            NICKEL SIZED HAIL REPORTED 3 MILES NORTH OF ENOREE

0348 PM     HAIL             GREENWOOD               34.19N 82.15W
05/20/2006  E0.88 INCH       GREENWOOD          SC   TRAINED SPOTTER

            DIME TO NICKEL SIZED HAIL REPORTED ALONG FLORIDA AVENUE
            IN GREENWOOD.

0350 PM     HAIL             3 NE BLACKSBURG         35.15N 81.48W
05/20/2006  E1.00 INCH       CHEROKEE           SC   COUNTY OFFICIAL

            DIME TO QUARTER SIZED HAIL AS WELL AS TREES DOWN 3 MILES
            NE OF THE CITY OF BLACKSBURG.

&&

BSH

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
411 PM EDT SAT MAY 20 2006

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

0405 PM     HAIL             5 SE SALEM              34.84N 82.92W
05/20/2006  E1.75 INCH       OCONEE             SC   TRAINED SPOTTER

&&

HG

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
412 PM EDT SAT MAY 20 2006

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

0408 PM     HAIL             5 E LONG CREEK          34.77N 83.17W
05/20/2006  E0.75 INCH       OCONEE             SC   TRAINED SPOTTER

            SPOTTER REPORTED DIME SIZED HAIL 5 MILES EAST OF LONG
            CREEK.

&&

BSH