Special Weather Statement, NWS Greenville-Spartanburg, SC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
604 PM EDT FRI APR 15 2011

.SYNOPSIS...
A VIGOROUS STORM SYSTEM WILL REACH OUR AREA LATE TONIGHT AND EARLY
SATURDAY...THEN MOVE OFF THE MID ATLANTIC COAST SATURDAY EVENING.
HIGH PRESSURE WILL BUILD OVER THE REGION SUNDAY AND REMAIN THROUGH
THE FIRST HALF OF NEXT WEEK.

&&

.NEAR TERM /THROUGH SATURDAY/...
AS OF 6 PM...AXIS OF GREATER MLCAPE VALUES WILL CONTINUE TO EXPAND
NORTHWARD INTO N GA AND SE TENN THIS EVENING...AND WITHIN STRONG
DEEP LAYERED SHEARED ENVIRONMENT...EMBEDDED SUPERCELL THREAT WILL
BE SEEN WITHIN NEWLY ISSUED TOR WATCH WHICH IS IN EFFECT FOR AREAS
JUST WEST OF OUR CWFA. 88D LOOPS SHOW WIDESPREAD SHOWERS ADVECTING
INTO SW NC...AND WITHIN STRENGTHENING WAA/UPSLOPE FLOW...WILL
STEADILY EXPAND IN CVRG AND MAGNITUDE THIS EVENING WITH A MAINLY
ELEVATED TSTM POSSIBILITY ACRS OUR SW FRINGE COUNTIES.

STILL EXPECT THE /MAIN SHOW/ IN TERMS OF SEVERE WEATHER THREAT WILL
BE WITH COLD FRONTAL CONVECTION LATE TONIGHT/ EARLY SATURDAY.

SPEAKING OF THE LATE NIGHT/EARLY SATURDAY SEVERE THREAT...THE
MAGNITUDE OF THE THREAT REMAINS QUITE UNCERTAIN. AS OF 18Z...THE
WARM SECTOR BETWEEN THE COLD FRONT AND THE BACK EDGE OF THE
AFOREMENTIONED REMNANT MCS WAS FREE OF CONVECTION...ALTHOUGH SOME
SHOWERS WERE BEGINNING TO POP JUST WEST OF THE MISS RIVER. THE
LATEST GUIDANCE FROM SPC AND SHORT TERM MODELS INDICATES CONVECTION
SHOULD DEVELOP/BLOSSOM ALONG THE COLD FRONT LATER THIS AFTERNOON.
HOW THIS WILL EVOLVE DOWNSTREAM OVER THE TENN/OHIO VALLEYS REMAINS
SOMEWHAT MYSTERIOUS TO ME...AS THE ONGOING RAIN/DENSE CIRRUS SHIELD
WILL CONTINUE TO LIMIT DESTABILIZATION. WHILE FORCING/WIND SHEAR
WILL BE TREMENDOUS...I JUST CAN/T SEE HOW WE/RE GOING TO DEVELOP THE
TYPE OF INSTABILITY TO RESULT IN THE TYPE OF SIGNIFICANT OUTBREAKS
THAT WERE SEEN EARLIER THIS MONTH. CERTAINLY...THE THREAT IS
NON-ZERO...BUT BELIEVE IT SHOULD BE MORE LOCALIZED/ISOLATED IN
NATURE AND THE SPC SLIGHT RISK IS PROBABLY ABOUT RIGHT.

THE SEVERE THREAT REMAINS SOMEWHAT MUDDY DURING THE DAYLIGHT HOURS
SATURDAY. WE ARE FAVORING THE FASTER TIMING OF THE GFS. THIS IS
BASED UPON THE FACT THAT MODEL GUIDANCE HAS GENERALLY BEEN TOO SLOW
IN PUSHING ORGANIZED CONVECTION ACROSS THE WESTERN CAROLINAS IN
PREVIOUS EVENTS THIS SEASON...PROBABLY DUE TO CONVECTIVE COLD POOL
INTERACTIONS DOMINATING SYNOPTIC SCALE FORCING. WITH THIS IN
MIND...WE ANTICIPATE MOST CONVECTION BEING EAST OF THE AREA BY NOON.
AGAIN...SPC PAINTING THE DAY 2 MODERATE RISK EAST OF OUR CWFA SEEMS
REASONABLE.

AS FAR AS ADDITIONAL THREATS...HEAVY RAIN WILL ACCOMPANY THE FRONTAL
CONVECTION LATE TONIGHT/EARLY SATURDAY. AREAS ALONG THE BLUE RIDGE
MAY SEE A SOLID 2-3 INCHES BY THE TIME ALL IS SAID AND DONE.
HOWEVER...I DON/T THINK THIS WILL BE SUFFICIENT TO CAUSE ANY
SIGNIFICANT FLOODING PROBLEMS. WE WILL CONTINUE TO MENTION A HEAVY
RAIN THREAT IN THE HWO. THERE WILL ALSO BE HIGH ELEVATION WIND
CONCERNS...OWING TO 50-60 KT LLJ...AND POTENTIAL MTN WAVE
DEVELOPMENT. OF COURSE...THIS WILL MAINLY BE AN ISSUE WEST OF THE
MTNS...BUT THE HIGH ELEVATIONS OF THE TENN BORDER COUNTIES COULD SEE
VERY GUSTY WINDS LATE TONIGHT...AND THE LWA HAS BEEN UPGRADED TO AN
ADVISORY FOR THOSE ZONES.

&&

.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
AS OF 220 PM FRIDAY...UPPER TROF MOVES EAST OF THE AREA SAT NITE
WITH RISING HEIGHTS AND NEARLY ZONAL FLOW BY MONDAY. A COUPLE OF
WEAK SHORT WAVES BRUSH THE AREA OR MOVE THRU SUN AND MON. AT THE
SFC...COLD FRONT MOVES OFF SHORE SAT NITE WITH LINGERING MOISTURE
AND NW FLOW PRODUCING SOME SHOWERS OVER THE NC MTNS. BEST PRECIP CHC
WILL BE BEFORE MIDNIGHT WITH QUICKLY DIMINISHING CHC AFTER. H85
TEMPS AND PARTIAL THICKNESSES INDICATE SNOW COULD MIX WITH THE RAIN
BEFORE ENDING. HOWEVER...DO NOT EXPECT ANY ACCUMS GIVEN THE VERY
LIGHT QPF AND DIMINISHING PRECIP CHC AFTER MIDNIGHT. ANY FREEZING
TEMPS SHOULD BE RELEGATED TO THE HIGHEST PEAKS. ALTHOUGH FROSTY
TEMPS WILL DEVELOP IN SOME VALLEYS...THINK ANY FROST WILL BE PATCHY
GIVEN THE CONTINUED WINDY CONDITIONS. OUTSIDE OF THE MTNS EXPECT
DIMINISHING CLOUDS AND WINDS WITH LOWS UP TO 5 DEGREES BELOW NORMAL.

HIGH PRESSURE BUILDS INTO THE AREA SUNDAY AND MOVES EAST OF THE AREA
MONDAY AS A WARM FRONT DEVELOPS TO OUR NORTH. EXPECT CLEAR SKIES
SUNDAY WITH WAVES OF MID AND HIGH CLOUDS MOVING OVER SUN NITE THRU
MON. NO PRECIP EXPECTED WITH LOW LEVELS REMAINING DRY EVEN WITH SLY
FLOW AND ANY SIGNIFICANT FORCING WELL TO OUR NORTH AND WEST. HIGHS
SUNDAY NEAR NORMAL EAST AND A LITTLE ABOVE WEST...WARMING AROUND 5
DEGREES MONDAY. LOWS NEAR NORMAL SUN NITE.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 210 PM FRIDAY...HIGH PRESSURE WILL BE OVER OUR REGION TO START
THE MEDIUM RANGE PERIOD MONDAY NIGHT.  SOME SHOWERS AND PERHAPS A
STORM COULD FORM MAINLY OVER THE MOUNTAINS LATE TUESDAY. AS THE NEXT
STORM SYSTEM REACHES THE GREAT LAKES...THE ASSOCIATED COLD FRONT
WILL SLOWLY CROSS TENNESSEE WEDNESDAY AND THURSDAY.  INCREASED
INSTABILITY WILL OCCUR SOUTHEAST OF THE FRONT.  MINOR LOWS ARE
LIKELY TO MOVE ALONG THE FRONT WITH THE BEST POPS FOR OUR REGION TO
BE ON THURSDAY AFTERNOON.  THERE ARE DIFFERENCES IN HOW THE GFS AND
ECMWF DEPICT THE EVOLUTION OF THE FRONT AND HOW LONG IT LINGERS IN
OUR AREA.  AT THIS POINT...HAVE DECREASED POPS GOING INTO FRIDAY AS
PERHAPS ANOTHER STORM SYSTEM FORMS OVER THE SOUTHERN PLAINS. THE
RESULT OF THAT WOULD BE TO LIFT THE FRONT BACK NORTH AS A WARM
FRONT.  THE PREVIOUS GFS HAD INDICATED A COOL AIR WEDGE NOSING DOWN
THE EAST COAST FRIDAY. HOWEVER...THAT IS LOOKING LESS PROBABLE.
TEMPERATURES SHOULD BE A FEW DEGREES ABOVE NORMAL THROUGH THE
WEEK...WARMEST ON WEDNESDAY WITH LOW TO MID 80S ACROSS MOST OF THE
FORECAST AREA.

&&

.AVIATION /22Z FRIDAY THROUGH WEDNESDAY/...
AT KCLT...GUSTY SE WINDS WILL ONLY STRENGTHEN DURING THE
AFTERNOON...AS STRONG STORM SYSTEM/COLD FRONT APPROACHES FROM THE
TENN VALLEY. WINDS WILL CONTINUE TO BE AN ISSUE OVERNIGHT...
REMAINING IN THE 10 TO 15 KT RANGE. IN FACT...GUSTS IN THE LOWER 20S
MAY PERSIST THROUGH THE NIGHT AS WELL. WINDS WILL TURN TOWARD THE SW
AND INCREASE BY THE END OF THE PERIOD. OTHERWISE...INCREASINGLY
MOIST SE FLOW IS EXPECTED TO RESULT IN LOWERING CIGS OVERNIGHT...
WITH MVFR CONDITIONS EXPECTED AROUND MIDNIGHT. FURTHER LOWERING TO
IFR IS EXPECTED DURING THE PRE-DAWN HOURS. SHOWER AND THUNDERSTORM
CHANCES WILL INCREASE AROUND SUNRISE. THUNDER IS NOT A SLAM
DUNK...SO THE CONVECTIVE PORTION OF THE TAF HAS BEEN LIMITED TO CB.
REDUCTION TO AT LEAST MVFR VISBY CAN ALSO BE EXPECTED.

ELSEWHERE...MOIST/STRONG SE FLOW WILL PERSIST THROUGH THE
OVERNIGHT...WITH GUSTS IN THE 20S EXPECTED TO CONTINUE IN MOST
AREAS. CLOUD HEIGHTS WILL BEGIN TO LOWER THIS EVENING...WITH MOST
LOCATIONS EXPECTED TO SEE MVFR CONDITIONS BEFORE MIDNIGHT...WITH IFR
CIGS EXPECTED AFTER MIDNIGHT. IN THE INTERIM...TERRAIN INDUCED
SHOWERS WILL BE POSSIBLE LATER THIS AFTERNOON/EVENING...PARTICULARLY
ALONG/NW OF THE BLUE RIDGE (KAVL). SHOWER AND THUNDERSTORM CHANCES
WILL BETWEEN MIDNIGHT AND SUNRISE AS A STRONG COLD FRONT APPROACHES
FROM THE TENN VALLEY. THUNDER IS NOT A SLAM DUNK...SO THE CONVECTIVE
PORTION OF THE TAF HAS BEEN LIMITED TO CB. REDUCTION TO AT LEAST
MVFR VISBY CAN ALSO BE EXPECTED. CONDITIONS SHOULD BEGIN TO IMPROVE
RAPIDLY FROM WEST TO EAST BY THE END OF THE PERIOD. HOWEVER...VERY
GUSTY SW WINDS ARE EXPECTED BEHIND THE FRONT (BY THE END OF THE
PERIOD).

OUTLOOK...VERY GUSTY SW WINDS ARE EXPECTED SAT AFTERNOON...
DIMINISHING DURING THE EVENING. DRY HIGH PRESSURE RETURNS FOR EARLY
NEXT WEEK.

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...LAKE WIND ADVISORY UNTIL 8 AM EDT SATURDAY FOR NCZ053-059-
     062>065-501-503-505-507-509.
     WIND ADVISORY UNTIL 8 AM EDT SATURDAY FOR NCZ033-048>052-058.
SC...NONE.

&&

SYNOPSIS...DEO
NEAR TERM...CSH/JDL
SHORT TERM...RWH
LONG TERM...DEO
AVIATION...JDL

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
605 PM EDT FRI APR 15 2011

GAZ010-017-018-026-028-029-NCZ035>037-056-057-068>072-082-502-504-
506-508-510-SCZ001>014-019-162000-
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-
605 PM EDT FRI APR 15 2011

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

.DAY ONE...THIS AFTERNOON AND TONIGHT.

RAIN SHOWERS AND A FEW THUNDERSTORMS WILL DEVELOP LATER THIS
EVENING AND CONTINUE OVERNIGHT. THE MAIN THREAT THIS EVENING WILL
BE FROM LOCALIZED HEAVY RAIN AND CLOUD TO GROUND LIGHTNING. DURING
THE PRE-DAWN HOURS...A LINE OF SHOWERS AND THUNDERSTORMS WILL MOVE
ACROSS THE REGION...BRINGING A THREAT OF DAMAGING STRAIGHT LINE
WINDS AND ISOLATED TORNADOES.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY.

WIDESPREAD SHOWERS AND SCATTERED THUNDERSTORMS WILL MOVE EAST
ACROSS THE AREA SATURDAY. DAMAGING STRAIGHT LINE WINDS AND
ISOLATED TORNADOES WILL REMAIN POSSIBLE...MAINLY ACROSS THE
PIEDMONT.

.SPOTTER INFORMATION STATEMENT...

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

NCZ033-048>052-058-162000-
AVERY-MADISON-YANCEY-MITCHELL-SWAIN-HAYWOOD-GRAHAM-
605 PM EDT FRI APR 15 2011

 ...WIND ADVISORY IN EFFECT UNTIL 8 AM EDT SATURDAY...

THIS HAZARDOUS WEATHER OUTLOOK IS FOR WESTERN NORTH CAROLINA.

.DAY ONE...THIS AFTERNOON AND TONIGHT.

PLEASE LISTEN TO NOAA WEATHER RADIO OR GO TO WEATHER.GOV ON THE
INTERNET FOR MORE INFORMATION ABOUT THE FOLLOWING HAZARDS.

   WIND ADVISORY.

RAIN SHOWERS AND A FEW THUNDERSTORMS WILL DEVELOP OVER THE
MOUNTAINS THIS EVENING AND CONTINUE THROUGH THE NIGHT. THE MAIN
THREAT THIS EVENING WILL BE FROM LOCALIZED HEAVY RAIN AND CLOUD TO
GROUND LIGHTNING. DURING THE PRE-DAWN HOURS...A LINE OF SHOWERS
AND THUNDERSTORMS WILL MOVE ACROSS THE REGION...BRINGING A THREAT
OF DAMAGING STRAIGHT LINE WINDS.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY.

PLEASE LISTEN TO NOAA WEATHER RADIO OR GO TO WEATHER.GOV ON THE
INTERNET FOR MORE INFORMATION ABOUT THE FOLLOWING HAZARDS.

   WIND ADVISORY.

DAMAGING STRAIGHT LINE WINDS WILL REMAIN POSSIBLE EARLY SATURDAY.
RAINFALL TOTALS OF 2 TO 3 INCHES ARE EXPECTED ACROSS THE MOUNTAINS
AND ADJACENT FOOTHILLS BY THE TIME THE RAIN ENDS SATURDAY MORNING.
WITH. SOME URBAN AND SMALL STREAM FLOODING WILL BE POSSIBLE.

.SPOTTER INFORMATION STATEMENT...

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

NCZ053-059-062>065-501-503-505-507-509-162000-
BUNCOMBE-NORTHERN JACKSON-MACON-SOUTHERN JACKSON-TRANSYLVANIA-
HENDERSON-CALDWELL MOUNTAINS-BURKE MOUNTAINS-MCDOWELL MOUNTAINS-
RUTHERFORD MOUNTAINS-POLK MOUNTAINS-
605 PM EDT FRI APR 15 2011

...LAKE WIND ADVISORY IN EFFECT UNTIL 8 AM EDT SATURDAY...

THIS HAZARDOUS WEATHER OUTLOOK IS FOR WESTERN NORTH CAROLINA.

.DAY ONE...THIS AFTERNOON AND TONIGHT.

PLEASE LISTEN TO NOAA WEATHER RADIO OR GO TO WEATHER.GOV ON THE
INTERNET FOR MORE INFORMATION ABOUT THE FOLLOWING HAZARDS.

   LAKE WIND ADVISORY.

RAIN SHOWERS AND A FEW THUNDERSTORMS WILL DEVELOP OVER THE
MOUNTAINS THIS EVENING AND CONTINUE THROUGH THE NIGHT. THE MAIN
THREAT THIS EVENING WILL BE FROM LOCALIZED HEAVY RAIN AND CLOUD TO
GROUND LIGHTNING. DURING THE PRE-DAWN HOURS...A LINE OF SHOWERS
AND THUNDERSTORMS WILL MOVE ACROSS THE REGION...BRINGING A THREAT
OF DAMAGING STRAIGHT LINE WINDS.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY.

PLEASE LISTEN TO NOAA WEATHER RADIO OR GO TO WEATHER.GOV ON THE
INTERNET FOR MORE INFORMATION ABOUT THE FOLLOWING HAZARDS.

   LAKE WIND ADVISORY.

DAMAGING STRAIGHT LINE WINDS WILL REMAIN POSSIBLE EARLY SATURDAY.
RAINFALL TOTALS OF 2 TO 3 INCHES ARE EXPECTED ACROSS THE MOUNTAINS
AND ADJACENT FOOTHILLS BY THE TIME THE RAIN ENDS SATURDAY MORNING.
WITH. SOME URBAN AND SMALL STREAM FLOODING WILL BE POSSIBLE.

.SPOTTER INFORMATION STATEMENT...

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

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
621 PM EDT FRI APR 15 2011

GAZ010-017-NCZ062-152300-
HABERSHAM-MACON-RABUN-
621 PM EDT FRI APR 15 2011

...A STRONG THUNDERSTORM WILL AFFECT MACON...NORTHERN HABERSHAM AND
RABUN COUNTIES THROUGH 700 PM EDT...

AT 620 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM 4 MILES NORTHEAST OF GADDISTOWN...OR 10 MILES
SOUTHWEST OF BLAIRSVILLE...MOVING NORTHEAST AT 40 MPH.

THIS STORM WILL BE NEAR...
  BATESVILLE...
  LAKE BURTON...

DIME SIZE HAIL AND WIND GUSTS OF 40 TO 50 MPH ARE EXPECTED WITH THIS
STORM. INTENSE 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 3524 8369 3530 8344 3499 8315 3482 8327
      3482 8330 3479 8333 3475 8332 3462 8340
      3458 8364 3466 8367 3476 8363 3481 8368
      3489 8366 3494 8360 3495 8356 3502 8353
      3515 8366 3516 8374

HG