Severe Thunderstorm Warning 34, NWS Greenville-Spartanburg, SC

744 
WWUS52 KGSP 241155
SVSGSP

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
755 AM EDT SAT MAR 24 2012

NCC089-149-175-SCC045-241205-
/O.CAN.KGSP.SV.W.0034.000000T0000Z-120324T1230Z/
HENDERSON NC-TRANSYLVANIA NC-POLK NC-GREENVILLE SC-
755 AM EDT SAT MAR 24 2012

...THE SEVERE THUNDERSTORM WARNING FOR NORTHWESTERN GREENVILLE...
WESTERN POLK...CENTRAL TRANSYLVANIA AND HENDERSON COUNTIES IS
CANCELLED...

THE STORM WHICH PROMPTED THE WARNING HAS WEAKENED BELOW SEVERE
LEVELS.

LAT...LON 3548 8229 3540 8226 3540 8225 3523 8215
      3507 8278 3508 8277 3507 8285 3523 8293
TIME...MOT...LOC 1155Z 248DEG 26KT 3522 8257

$$

JOH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
305 AM EDT SAT MAR 24 2012

.SYNOPSIS...
A COLD FRONT WILL CROSS THE CAROLINAS AND NORTHEAST GEORGIA THIS
MORNING...FOLLOWED BY AN UPPER LEVEL LOW ON SUNDAY. DRY HIGH
PRESSURE WILL THEN BUILD ACROSS THE REGION SUNDAY NIGHT AND LINGER
THROUGH EARLY WEDNESDAY. ANOTHER WEAK COLD FRONT WILL LAY OVER THE
AREA FROM THE NORTH ON THURSDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
THROUGH THE PRE-DAWN HOURS...SHOWERS WILL CONTINUE TO BLOSSOM OVER
THE PIEDMONT OF THE CAROLINAS IN A WARM CONVEYOR BELT-LIKE SOUTHERLY
WARM ADVECTION FLOW. SATELLITE TRENDS SHOW THIS FEATURE SLOWLY
TRANSLATING EASTWARD DURING THE EARLY MORNING HOURS...AND MOVING
EAST OF THE FCST AREA AROUND 09Z-10Z. THIS SHOULD MOVE SOME OF THE
SHOWER ACTIVITY OFF TO THE EAST...BUT BACKING LOW LEVEL FLOW WILL
CONTINUE TO RUN UP THE BLUE RIDGE AND FORCE ADDITIONAL SHOWERS
THROUGH SUNRISE. WILL RAISE PRECIP CHANCES TO LIKELY WHERE THIS
FEATURE MOVES THROUGH. MEANWHILE...MORE VIGOROUS CONVECTION
CONTINUES TO FIRE IN A BAND OVER ERN TN AND NW GEORGIA. THIS
ACTIVITY WILL EVENTUALLY REACH THE WRN PART OF THE FCST AREA IN THE
07Z TO 08Z TIME FRAME. WILL BE AMENDING THE FCST TO ACCT FOR
THIS...WITH PRECIP CHANCES BACK INTO THE LIKELY RANGE...IF IT HOLDS
TOGETHER. TEMP TRENDS LOOK GOOD.

THE UPPER LOW SEEN ON WATER VAPOR IMAGERY WILL STEADILY APPROACH
TODAY AND MOVE ACROSS THE SRN APPALACHIANS AND WESTERN CAROLINAS
LATE TONIGHT. THIS FEATURE WILL PROVIDE PLENTY OF FORCING FOR
OCCASIONAL SHOWERS AND THUNDERSTORMS THROUGH AT LEAST THIS
EVENING... AS PERIODIC VORT LOBES ROTATE AROUND THE LOW AND PATCHES
OF UPPER DIVERGENCE MOVE OVERHEAD. IN PARTICULAR...THE MODELS FOCUS
ON A VORT CENTER THAT MOVES IN FROM THE WEST THIS AFTERNOON. THINK
THE GFS IS DEFICIENT IN SHOWING THE POTENTIAL COVERAGE OF STORMS
FORCED BY THIS WAVE...AND MUCH PREFER THE NAM DEPICTION. OF NOTE IS
A MID LEVEL JETLET THAT MOVES IN FROM THE WEST AT 700MB THIS
AFTERNOON. THIS SHOULD CAUSE ENOUGH OF AN INCREASE IN SHEAR TO
ORGANIZE STORMS LATER IN THE DAY. WOULD NOT BE SURPRISED TO SEE
CONVECTIVE INITIATION IN THE EARLY AFTERNOON JUST EAST OF THE
MTNS...WITH STORMS CONSOLIDATING INTO A SQUALL LINE THAT MOVES OVER
THE PIEDMONT IN THE LATE AFTERNOON AND EVENING AND PRODUCES NUMEROUS
DAMAGING WIND GUSTS. I WILL NOT RULE OUT A BRIEF TORNADO EITHER...
BECAUSE WE SHOULD HAVE ENOUGH BOUYANCY AND SHEAR FOR A FEW MINI
SUPERCELLS. THINK THE NEW DAY1 OUTLOOK IS RIGHT ON THE MONEY AND
WOULD EXPECT A WATCH OVER THE PIEDMONT SOME TIME LATER TODAY.
THIS ACTIVITY SHOULD MOVE OFF TO THE EAST IN THE EVENING AND PRECIP
CHANCES SHOULD WIND DOWN...BUT NOT COMPLETELY GO AWAY OVERNIGHT WITH
THE UPPER LOW MOVING IN. TEMPS WERE NUDGED TOWARD THE GUIDANCE BLEND.

&&

.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 145 AM SATURDAY...THE SHORT TERM PICKS UP AT 12Z ON SUNDAY
WITH THE CLOSED H5 LOW CENTERED OVER THE CAROLINAS AND UPPER RIDGING
READY TO BUILD IN ITS WAKE. THE CLOSED LOW WILL OPEN UP AS IT MOVES
OFF THE EAST COAST AND EVENTUALLY BECOMES ABSORBED BY A DEEPENING
LONGWAVE UPPER TROF. BY THE END OF THE PERIOD AT 12Z ON TUES...THE
AXIS OF THE UPPER RIDGE SHOULD BE JUST TO OUR WEST WITH NWLY H5 FLOW
PERSISTING OVER THE AREA.

ON SUNDAY...THE SFC LOW WILL GRADUALLY MOVE OFF THE CAROLINA COAST
WITH ITS ASSOCIATED COLD FRONT WELL TO OUR SE. MOIST WRAP AROUND
NWLY LOW LVL FLOW WILL SETTLE OVER THE CWFA SUNDAY AFTERNOON AND
PERSIST THRU MOST OF MONDAY. PRECIP CHANCES ARE STILL EXPECTED TO
TAPER OFF FROM THE SW TO THE NE WITH THE HIGHEST POPS LINGERING OVER
THE NC MTS FROM THE WRAP AROUND MOISTURE. BY 00Z MONDAY...ONLY A
SLIGHT CHANCE POP REMAINS OVER PORTIONS OF THE PIEDMONT AND
FOOTHILLS WITH SLIGHT TO SOLID CHANCE LINGERING OVER THE MTS FOR
ANOTHER 6 TO 12 HRS. THE NAM CONTINUES TO BRING HIGHER AMOUNTS OF
1000-500MB MOISTURE OVER THE FCST AREA THRU MIDDAY MONDAY BEFORE IT
FINALLY DRIES THINGS UP. MOST OF THE OTHER MODELS DRY FASTER...SO
AGAIN I HAVE LEANED AWAY FROM THE NAM SOLUTION. IN TERMS OF SVR WX
POTENTIAL...SPC HAS OUR FAR EASTERN ZONES WITHIN A SLIGHT RISK...IE
5% AREA...FOR SUN AFTERNOON/EVENING...YET THIS IS PROBABLY TOO
OPTIMISTIC BASED ON THE LATEST MODEL PROFILES. BY 18Z SUN...OUR CWFA
SHOULD BE UNDER PREDOMINATELY NEGATIVE VORT ADVECTION WITH THE H5
LOW SLIDING TO OUR EAST. THIS COUPLED WITH VERY WEAK AMOUNTS OF
INSTABILITY AND UNFAVORABLE LOW LVL SHEAR PROFILES...SHOULD KEEP OUR
ACTIVITY TO MOSTLY SHOWERS AND MAYBE A FEW TS.

TEMPS WERE NOT CHANGED MUCH FROM THE PREVIOUS FCST AND WILL REMAIN
ABOUT 4 TO 8 DEGREES ABOVE CLIMO EVEN WITH THE COOLER NORTHERLY FLOW
PUSHING INTO THE REGION.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 230 PM FRIDAY...THE LATEST EXTENDED MODELS ARE IN GOOD
AGREEMENT WITH STRONG CANADIAN SURFACE HIGH PRESSURE OVER THE GREAT
LAKES PUSHING INTO OUR FORECAST AREA MONDAY AND LINGER INTO
WEDNESDAY. AS A RESULT...MOSTLY DRY CONDITIONS WITH COOLER
TEMPERATURES CAN BE EXPECTED ACROSS THE REGION THROUGH WEDNESDAY. A
WEAK COLD FRONT IS PROGGED TO CROSS THE CAROLINAS AND NE GEORGIA
WEDNESDAY NIGHT INTO THURSDAY MORNING. BOTH THE GFS AND THE ECMWF
INDICATE THAT THE LOWER PIEDMONT AREA WILL STAY MOSTLY DRY AS THE
UPPER LEVEL DYNAMICS WEAKENS AND THE AIRMASS REMAINS RELATIVELY DRY.
HOWEVER..DECENT LLVL NW FLOW LIFTING ALONG WITH WEAK DIURNAL
INSTABILITY OVER THE NC MOUNTAINS MAY SUPPORT FOR THE DEVELOPMENT OF
SCATTERED SHOWERS AND THUNDERSTORMS DURING THE PASSAGE OF THE FRONT.
HENCE...I MENTIONED 20-30 POPS THERE WITH MOSTLY DRY CONDITIONS
ELSEWHERE. FRIDAY AND SATURDAY...ANOTHER CANADIAN HIGH PRESSURE OVER
THE GREAT LAKES AND SE CANADA IS EXPECTED TO PUSH SOUTH ACROSS THE
REGION FOR MOSTLY DRY WEATHER AND MILD CONDITIONS THROUGH THE
PERIOD.

&&

.AVIATION /07Z SATURDAY THROUGH WEDNESDAY/...
AT KCLT...OCCASIONAL SHOWERS THROUGH 09Z-10Z TIME FRAME AS WARM
CONVEYOR BELT FEATURE ON SATELLITE IMAGERY TRANSLATES EASTWARD. THIS
SHOULD KEEP THE CEILING IN VFR...BUT A FEW BRIEF PERIODS OF MVFR
VISIBILITY IN HEAVIER SHOWERS ARE POSSIBLE. ONCE THIS ACTIVITY MOVES
EAST OF THE AIRFIELD...THE CEILING SHOULD DROP INTO MVFR RANGE FOR
THE BETTER PART OF THE MORNING. WIND WILL REMAIN S TO SW. CONVECTION
WILL DEVELOP AGAIN BY MIDDAY. CURRENT THINKING IS THAT THUNDERSTORMS
WILL DEVELOP ACROSS THE FOOTHILLS OR WRN UPSTATE OF SC IN THE EARLY
AFTERNOON AND MOVE EAST...PERHAPS AS A SQUALL LINE IN THE LATE
AFTERNOON TO EARLY EVENING...WITH ASSOCIATED FLIGHT RESTRICTIONS.
BE ON THE LOOKOUT FOR A THREAT OF DAMAGING WIND GUSTS AND LARGE HAIL
IN THE AFTERNOON AND EVENING. THE STORMS ARE NOT INDICATED IN THE
TAF BECAUSE TIMING CANNOT BE SPECIFIED RIGHT NOW. ONCE THE SHOWERS
AND STORMS MOVE EAST OF THE REGION IN THE EARLY EVENING...CONDITIONS
SHOULD BE VFR FOR SEVERAL HOURS.

ELSEWHERE...THE BACK EDGE OF THE WARM CONVEYOR BELT SHOWER
PRODUCTION WILL MOVE EAST OF THE REGION BY 09Z. EXPECT CEILING TO
FILL IN MVFR WITH IFR PATCHES DURING THE EARLY MORNING HOURS...AHEAD
OF THE NEXT LINE OF CONVECTION. MVFR CEILING WILL GRADUALLY LIFT BY
MID MORNING...THEN MORE SHOWERS AND STORMS SHOULD DEVELOP DURING THE
MIDDLE OF THE DAY. EXPECT CONDITIONS TO BECOME VFR OUTSIDE OF
CONVECTIVE STORMS GENERALLY BY 18Z.

OUTLOOK...SCATTERED SHOWERS WILL CONTINUE THROUGH SUNDAY AS AN UPPER
LOW CENTER MOVES SLOWLY ACROSS THE REGION. EXPECT MVFR RESTRICTIONS
SUN MRNG AND WITH HEAVIER SHWRS AND TSTMS. DRYING IS EXPECTED EARLY
NEXT WEEK.

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...JPT
NEAR TERM...PM
SHORT TERM...JPT
LONG TERM...JOH
AVIATION...PM

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
455 AM EDT SAT MAR 24 2012

GAZ018-026-028-029-NCZ035>037-056-057-068>072-082-502-504-506-508-
510-SCZ001>014-019-250900-
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-
455 AM EDT SAT MAR 24 2012

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 THIS MORNING WILL PRODUCE HEAVY RAIN THAT
COULD RESULT IN SOME MINOR FLOODING OF POOR DRAINAGE AREAS. THE
THUNDERSTORMS WILL BECOME MORE NUMEROUS THIS AFTERNOON AND
EVENING. SOME OF THE THUNDERSTORMS WILL BECOME SEVERE AND PRODUCE
DAMAGING WIND GUSTS AND LARGE HAIL...MAINLY EAST OF THE BLUE
RIDGE. WIND SHEAR WILL INCREASE IN THE AFTERNOON WHICH MAY
ORGANIZE THE THUNDERSTORMS INTO A SQUALL LINE ACROSS THE PIEDMONT.
ENOUGH INSTABILITY AND WIND SHEAR SHOULD BE PRESENT SUCH THAT AN
ISOLATED BRIEF TORNADO CANNOT BE RULED OUT. THE THUNDERSTORMS
SHOULD MOVE EAST OF THE REGION BY MID EVENING.

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

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-NCZ033-048>053-058-059-062>065-501-503-505-507-509-250900-
RABUN-HABERSHAM-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-
455 AM EDT SAT MAR 24 2012

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

.DAY ONE...TODAY AND TONIGHT.

NUMEROUS THUNDERSTORMS ARE EXPECTED TO MOVE ACROSS THE MOUNTAINS
TODAY. A FEW OF THE STORMS MAY BECOME SEVERE AND PRODUCE DAMAGING
WIND GUSTS AND LARGE HAIL...ALTHOUGH THE CHANCE WILL BE BETTER
EAST OF THE BLUE RIDGE. THE STORMS SHOULD MOVE EAST OF THE MOUNTAINS
DURING THE EARLY EVENING.

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

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.

MOORE

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
623 AM EDT SAT MAR 24 2012

GAZ010-NCZ062>064-SCZ001-241115-
MACON-OCONEE MOUNTAINS-RABUN-SOUTHERN JACKSON-TRANSYLVANIA-
623 AM EDT SAT MAR 24 2012

...A STRONG THUNDERSTORM WILL AFFECT NORTHEASTERN RABUN...NORTHERN
OCONEE...SOUTHEASTERN JACKSON...SOUTHEASTERN MACON AND SOUTHWESTERN
TRANSYLVANIA COUNTIES THROUGH 715 AM EDT...

AT 621 AM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM 5 MILES NORTHWEST OF CLAYTON...MOVING NORTHEAST
AT 25 MPH.

THIS STORM WILL BE NEAR...
  CLAYTON...
  DILLARD...
  OTTO...
  PINE MOUNTAIN...
  HIGHLANDS...
  CASHIERS...

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

FREQUENT LIGHTNING IS ALSO OCCURRING WITH THIS STORM. IF
OUTDOORS...STAY AWAY FROM ISOLATED HIGH OBJECTS SUCH AS TREES. MOVE
INDOORS IF POSSIBLE. WHEN INDOORS...STAY AWAY FROM WINDOWS AND DOORS
AND AVOID USING TELEPHONES UNLESS IT IS AN EMERGENCY. TRY TO UNPLUG
UNNECESSARY ELECTRICAL APPLIANCES BEFORE THE THUNDERSTORM APPROACHES.

LAT...LON 3525 8313 3528 8299 3506 8287 3504 8292
      3501 8292 3482 8342 3503 8351

JPT