Severe Thunderstorm Warning 63, NWS Greenville-Spartanburg, SC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
247 PM EDT MON APR 2 2012

.SYNOPSIS...
A COLD FRONT WILL SLOWLY CROSS THE WESTERN CAROLINAS FROM THE
NORTHEAST THIS AFTERNOON INTO THIS EVENING...THEN MOVE BACK NORTH
AS A WARM FRONT ON WEDNESDAY.  ANOTHER COLD FRONT IS EXPECTED TO
MOVE THROUGH THE AREA LATE THURSDAY INTO FRIDAY.

&&

.NEAR TERM /THROUGH TUESDAY/...
AS OF MID AFTERNOON...THE EXPECTED LULL HAS ENDED AND CONVECTIVE
INITIATION HAS TAKEN PLACE NEAR THE SURFACE BOUNDARY AT 18Z. SURFACE
BASED CAPE CONTINUES TO CLIMB INTO THE 1000-2000 J/KG RANGE TO THE S
AND W OF THE BOUNDARY. SOMEWHAT DRIER AIR OVER THE UPSTATE ALSO HAS
YIELDED FAVORABLE DCAPE VALUES FOR WET MICROBURSTS. CANNOT ARGUE
WITH LATEST SPC MESOSCALE DISCUSSION 0414 AND EXPECT TO SEE A FEW
CELLS THAT PRODUCE LARGE HAIL AND DAMAGING WIND GUSTS. THE PRIMARY
FOCUS SHOULD SHIFT TO THE CENTRAL AND SRN MTNS...WRN UPSTATE...AND
NE GEORGIA IN THE EARLY EVENING AS THE FRONT WRAPS AROUND AND ALIGNS
WITH THE SAVANNAH RIVER. THE FRONT SHOULD STALL IN THAT GENERAL
VICINITY OVERNIGHT...WHICH COULD RESULT IN CONVECTIVE ACTIVITY
PERSISTING THROUGH THE EARLY MORNING HOURS. DEEPER MOISTURE IS
EXPECTED TO SETTLE OVER THE SRN MTNS AND PROVIDE SOME FUEL FOR HEAVY
RAIN LATE TONIGHT...SO THAT BEARS WATCHING. THE FRONT WILL ALSO
PROVIDE A GRADIENT IN MIN TEMPS...PERHAPS AS MUCH AS 15 DEGREES OR
SO FROM THE NW PIEDMONT NEAR 50 TO NE GEORGIA IN THE LOWER 60S.

ON TUESDAY...THE OLD FRONT WILL STILL BE IN THE AREA. WEAK HIGH
PRESSURE SHOULD SLIP PAST ON THE COAST IN THE MORNING SUCH THAT BY
LATE IN THE DAY A LIGHT S FLOW SHOULD BE UNDERWAY. OTHER WEAK VORT
CENTERS WILL ALSO APPROACH AND UNDERCUT THE UPPER RIDGE FROM THE SW.
THIS WILL FAVOR A SHOWER/THUNDERSTORM CHANCE ONCE AGAIN OVER THE
HIGHER TERRAIN AND DOWN THE SAVANNAH RIVER VALLEY. THE SREF PRECIP
PATTERN LOOKS REASONABLE BUT THE MAGNITUDE LOOKS OVERDONE. HAVE
LIMITED THE POP TO 40 PERCENT FOR THE TIME BEING. TEMPS WERE KEPT
NEAR A BLEND OF THE GUIDANCE.

&&

.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/...
AS OF 215 PM MONDAY...THIS VERY ACTIVE PATTERN CONTINUES THROUGH MID
WEEK AS A CUT OFF UPPER LOW SLOWLY TRACKS ROUGHLY EAST FROM NEW
MEXICO TUESDAY EVENING. THE FRONT OVER GEORGIA WILL SLOWLY DISSIPATE
TUESDAY NIGHT. CAPE VALUES EARLY IN THE EVENING WILL BE AROUND 1000
OVER FAR WESTERN ZONES...MAINLY NE GA TO AROUND FONTANA LAKE.  THE
WEATHER SHOULD BE FAIRLY QUIET LATE TUESDAY NIGHT ALTHOUGH THE NAM
HINTS AT ACTIVITY A LITTLE MORE EAST THAN THE FAR WESTERN MOUNTAINS.

WEDNESDAY HIGH TEMPS SHOULD BE SEVERAL DEGREES ABOVE NORMAL
DEPENDING ON WHAT AREAS HAVE LATER ONSET OF SHOWERS AND STORMS.
EARLIER ONSET WILL KEEP TEMPS DOWN CLOSER TO NORMAL.  EACH MODEL HAS
VARIOUS TIMING DIFFERENCES BUT EACH MODEL HAS A SPOKE OF LINEAR
CONVECTION SPINNING FROM THE GULF STATES IN OUR DIRECTION WEDNESDAY
NIGHT AND THURSDAY.  THE GFS IS FASTER BUT HAS THIS FEATURE FADING
OUT AS IT REACHES THE NC MOUNTAINS.  THE NAM...SREF AND ECMWF KEEP
IT TOGETHER AND HAVE IT ARRIVING THURSDAY AFTERNOON AND CONTINUING
INTO EARLY EVENING AS IT PULLS UP TOWARD VIRGINIA.  TEMPERATURES
WILL BE A FEW DEGREES LOWER ON THURSDAY AS THIS DEEPER MOISTURE GETS
INTO OUR REGION.

CAPE VALUES ARE SHOWN TO BE A BIT HIGHER LATE WEDNESDAY AND LESS ON
THURSDAY.  POTENTIAL FOR ANY DAMAGING WIND EVENT WOULD BE GREATER
LATE WEDNESDAY.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
AS OF 1230 PM MONDAY...THE ACTIVE WEATHER PATTERN WILL CONTINUE INTO
THE EXTENDED PORTION OF THE FORECAST...BUT ONLY INTO FRIDAY...THEN A
QUIET WEEKEND.  AT 00Z FRIDAY...THE CUT OFF LOW IS SHOWN TO BE OVER
NORTHERN ARKANSAS ON THE ECMWF AND OVER ST LOUIS ON THE GFS. THE
ECMWF DIVES THIS LOW SE TO GEORGIA ON FRIDAY WHILE THE GFS MOVE THE
LOW ALMOST DUE EAST TO THE VIRGINIAS.  BOTH MODELS OPEN THE LOW UP
TO THE TROUGH MOVING OFF THE EAST COAST BY LATE FRIDAY AND THE GFS
THEN MOVES THE SHORTWAVE SE TO THE CAROLINA COAST FRIDAY NIGHT.  IN
SOME FORM...WE WILL HAVE PERIODS OF SHOWERS AND A STORM OR TWO UNTIL
THE SHORTWAVE MOVES OFF THE COAST FRIDAY NIGHT.  MUCH LOWER
THICKNESS VALUES AND EXTENSIVE CLOUD COVER SHOULD KEEP HIGH TEMPS A
FEW DEGREES BELOW NORMAL ON FRIDAY...PARTICULARLY FOR NC PIEDMONT
AND FOOTHILLS.

UPPER RIDGING COUPLED WITH SURFACE HIGH PRESSURE LOCATED TO OUR
NORTH OVER THE WEEKEND WILL GIVE US DRY WEATHER WITH NEAR NORMAL
TEMPERATURES.  A COLD FRONT ASSOCIATED WITH THE NEXT TROUGH WILL BE
APPROACHING FROM THE NORTHWEST EARLY NEXT WEEK AND RESULT IN
INCREASING CLOUDINESS.  AT THE CURRENT TIME...WILL ONLY INCLUDE
SIGHT POPS MONDAY NIGHT OF NEXT WEEK OVER THE NC MOUNTAINS.

&&

.AVIATION /19Z MONDAY THROUGH SATURDAY/...
AT KCLT...VFR EXPECTED FOR THE NEXT 12 HOURS. SATELLITE IMAGERY
SUGGESTS THE POSITION OF THE SURFACE FRONT CUTTING WEST TO EAST
ACROSS THE PIEDMONT. THIS COULD BE THE FOCUS FOR SHOWERS OR
THUNDERSTORMS LATER THIS AFTERNOON...BUT THAT IS NOT EXPECTED TO
HAPPEN UNTIL THE BOUNDARY MOVES TO THE SOUTHWEST OF THE CLT METRO
AREA. INSTEAD...HIGH BASED STRATOCU AND ALTOCU WILL PREVAIL. THE
FRONT SHOULD MOVE THROUGH SOME TIME IN THE MIDDLE PART OF THE
EVENING...WHICH WILL SHIFT THE WIND TO SOMETHING MORE NORTHEASTERLY.
THERE APPEARS TO BE LITTLE CHANCE FOR FOG LATE TONIGHT. ON
TUESDAY...WE COULD POP UP AN MVFR CEILING IN THE MIDDLE PART OF THE
MORNING AS THE BOUNDARY LAYER HEATS UP. CONFIDENCE ONLY BARELY HIGH
ENOUGH TO MENTION...THOUGH.

ELSEWHERE...A BACK DOOR COLD FRONT WILL SLOWLY DROP ACROSS THE
REGION THIS AFTERNOON...STALLING FOR A WHILE BETWEEN KGSP AND KAND
BY EARLY EVENING. THUNDERSTORMS SHOULD DEVELOP NEAR THE FRONTAL
BNDRY BY LATE AFTN...AND CONTINUE INTO THE NIGHT. CB/S HAVE BEEN
RETAINED AT THE UPSTATE TAFS AND KAVL TO ACCOUNT FOR THIS...AND WILL
AMEND AS STORMS DEVELOP. SOME OF THE STORMS TODAY WILL PRODUCE
STRONG OUTFLOW BOUNDARIES. LAMP GUIDANCE CONTINUES WITH THE IDEA
THAT A BROKEN LOW CLOUD CEILING WILL FORM IN THE MVFR RANGE AFTER
SUNRISE ON TUESDAY...BUT SHOULD SCATTER OUT AFTER ABOUT TWO HOURS.

OUTLOOK...ISOLATED TO SCATTERED MAINLY DIURNAL SHOWERS AND TSTMS
WILL BE POSSIBLE THRU THE PERIOD...WITH ASSOCIATED FLIGHT
RESTRICTIONS. TSTM CHC WILL INCREASE TOWARD MID-WEEK...AS A COLD
FRONT APPROACHES FROM THE WEST.

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...PM
SHORT TERM...DEO
LONG TERM...DEO
AVIATION...PM

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
600 AM EDT MON APR 2 2012

GAZ010-017-018-026-028-029-NCZ048>053-058-059-062>065-505>510-
SCZ001>007-010>013-019-031000-
RABUN-HABERSHAM-STEPHENS-FRANKLIN-HART-ELBERT-MADISON-YANCEY-
MITCHELL-SWAIN-HAYWOOD-BUNCOMBE-GRAHAM-NORTHERN JACKSON-MACON-
SOUTHERN JACKSON-TRANSYLVANIA-HENDERSON-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-ANDERSON-ABBEVILLE-LAURENS-UNION SC-
GREENWOOD-
600 AM EDT MON APR 2 2012

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

.DAY ONE...TODAY AND TONIGHT.

A COLD FRONT WILL EXTEND ROUGHLY ALONG A LINE FROM ASHEVILLE TO
GREENVILLE AND GREENWOOD BY LATE AFTERNOON. SCATTERED
THUNDERSTORMS ARE EXPECTED TO DEVELOP ALONG AND SOUTH OF THE
FRONT. SOME OF THE THUNDERSTORMS COULD BECOME SEVERE...PRODUCING
AREAS OF DAMAGING STRAIGHT LINE WINDS AND HAIL UP TO THE SIZE OF
QUARTERS.

UPSLOPE FLOW IMMEDIATELY BEHIND THE FRONT IS LIKELY TO SUPPORT
CONTINUED THUNDERSTORM DEVELOP TONIGHT ACROSS THE SOUTHERN
APPALACHIANS. AS THESE STORMS WILL BE SLOW MOVING OR
STATIONARY...A FEW AREAS OF FLASH FLOODING MAY DEVELOP.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY.

A SERIES OF SURFACE FRONTS WILL AFFECT THE REGION TUESDAY THROUGH
THURSDAY. PERIODIC THUNDERSTORM DEVELOPMENT IS EXPECTED DURING
THIS TIME. SOME OF THE STORMS MAY REACH SEVERE LEVELS...
ESPECIALLY DURING THE AFTERNOON AND EVENING HOURS.

.SPOTTER INFORMATION STATEMENT...

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

NCZ033-035>037-056-057-068>072-082-501>504-SCZ008-009-014-031000-
AVERY-ALEXANDER-IREDELL-DAVIE-CATAWBA-ROWAN-CLEVELAND-LINCOLN-GASTON-
MECKLENBURG-CABARRUS-UNION NC-CALDWELL MOUNTAINS-GREATER CALDWELL-
BURKE MOUNTAINS-GREATER BURKE-CHEROKEE-YORK-CHESTER-
600 AM EDT MON APR 2 2012

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

.DAY ONE...TODAY AND TONIGHT.

A ISOLATED THUNDERSTORM IS POSSIBLE THIS MORNING. BRIEF HEAVY RAIN
AND OCCASIONAL CLOUD TO GROUND LIGHTNING WILL BE THE MAIN THREAT
FROM THESE THUNDERSTORMS.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY.

A SERIES OF SURFACE FRONTS WILL AFFECT THE REGION TUESDAY THROUGH
THURSDAY. PERIODIC THUNDERSTORM DEVELOPMENT IS EXPECTED DURING
THIS TIME. SOME OF THE STORMS MAY REACH SEVERE LEVELS...
ESPECIALLY DURING THE AFTERNOON AND EVENING HOURS.

.SPOTTER INFORMATION STATEMENT...

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

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
1218 PM EDT MON APR 02 2012

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

0445 PM     TSTM WND DMG     MARSHALL                35.80N 82.68W
04/01/2012                   MADISON            NC   COUNTY OFFICIAL

            THUNDERSTORM WINDS BLEW DOWN THE TOWER OF RADIO STATION
            WHBK. THE TOWER WAS ESTIMATED TO BE 300 FEET HIGH.

&&

STUREY

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
341 PM EDT MON APR 2 2012

SCZ009-014-022030-
CHESTER-YORK-
341 PM EDT MON APR 2 2012

...A STRONG THUNDERSTORM WILL AFFECT NORTHEASTERN CHESTER AND
SOUTHEASTERN YORK COUNTIES THROUGH 430 PM EDT...

AT 338 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM NEAR ROCK HILL...MOVING SOUTH AT 20 MPH.

THIS STORM WILL BE NEAR...
  ROCK HILL...
  CATAWBA...
  RICHBURG...

SMALL HAIL...AND WIND GUSTS OF 30 TO 40 MPH ARE EXPECTED WITH THIS
STORM.

LAT...LON 3466 8088 3465 8115 3503 8116 3504 8090
      3484 8086 3482 8089 3477 8086 3474 8087
      3470 8085

ARK