Damaging Winds in South Carolina, July 3, 2011

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
236 PM EDT SUN JUL 3 2011

.SYNOPSIS...
HUMIDITY AND THUNDERSTORM CHANCES WILL INCREASE FOR LATE MONDAY AS A
WEAK COLD FRONT DRIFTS DOWN FROM THE NORTH. THIS FRONT WILL STALL
ATOP THE REGION AND SLOWLY DISSIPATE THROUGH MID WEEK.
ANOTHER COLD FRONT WILL APPROACH LATER IN THE WEEK.

&&

.NEAR TERM /THROUGH MONDAY/...
WATER VAPOR IMAGERY SHOWS A SHORTWAVE DIGGING INTO THE OH
VALLEY...ALLOWING THE UPSTREAM MID LEVEL RIDGE TO BREAK DOWN
SLIGHTLY ON THE LATEST RUC HEIGHT ANALYSIS. OVER OUR AREA...A LEE
SIDE TROUGH APPEARS TO BE IN PLACE ACROSS THE FOOTHILLS EARLY THIS
AFTERNOON. SFC BASED CAPE VALUES HAVE INCREASED TO 2000 TO 3000 J/KG
ACROSS MOST OF THE AREA. SCATTERED CONVECTION HAS TRIGGERED ALONG
THE MTNS IN THE SW FLOW AND BEST CONVERGENCE...AND COVERAGE WILL
LIKELY SPREAD AT LEAST INTO THE FOOTHILLS...IF NOT THE PIEDMONT...ON
WEAK NW WINDS ALOFT AND WITH OUTFLOW BOUNDARIES. WARM PROFILES ALOFT
UNDER THE NOSE OF THE RIDGE CONTINUE TO PRESENT A CHALLENGE FOR
LARGE HAIL PRODUCTION...BUT RESIDUAL MID LEVEL DRY AIR WILL CREATE A
MARGINAL DOWNBURST THREAT THROUGH EARLY EVENING. WEAK SHORTWAVES MAY
APPROACH THE NRN TIER OVERNIGHT AS HEIGHTS FALL...POSSIBLY KEEPING
ISOLATED SHOWERS GOING...MAINLY IN THE MTNS. ANOTHER WARM AND MUGGY
NIGHT IS EXPECTED AHEAD OF THE APPROACHING FRONT.

PRECIPITABLE WATER WILL STEADILY RISE TO NEARLY 2 INCHES IN MANY
FOOTHILL AND PIEDMONT AREAS THROUGH MON AFTN. THIS SHOULD ENHANCE
COVERAGE GIVEN THE IMPROVED FORCING FROM THE APPROACHING COLD
FRONT...A DEVELOPING LEE TROUGH IN THE WESTERLY FLOW ALOFT...AND
FALLING UPPER HEIGHTS. HOWEVER...MOISTENING AT MID LEVELS MAY ALSO
INHIBIT DOWNBURST SEVERE POTENTIAL SOMEWHAT. IN ADDITION...
DEEP LAYER SHEAR LOOKS VERY LIMITED FOR MON AFTN...WITH MAX SPEEDS
AROUND 20 KT AT 500 MB ACROSS THE NRN TIER LATE IN THE DAY. ALL
TOLD...EXPECT NUMEROUS STRONG TSTMS DURING THE PM HOURS...WITH SOME
LIKELY BECOMING SEVERE LATE IN THE DAY. THE SLOW MOVEMENT COULD ALSO
CREATE A HYDRO THREAT IF ANY TRAINING OF CELLS SETS UP.

&&

.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/...
AS OF 145 PM SUNDAY...LEFTOVER CONVECTION CONTINUING INTO MONDAY
NIGHT BUT BECOMING LESS IN THE LATE NIGHT.  THERE IS DIFFERENCES IN
TIMING BETWEEN THE MODELS AS THE NAM AND SREF HAVE THE FRONTAL BAND
MOISTURE AT 06Z TUESDAY FROM THE NC OUTER BANKS TO THE SC PIEDMONT
AND THE GFS HAS IT A LITTLE FARTHER NORTH.  THE GFS CONTINUES THE
TREND OF KEEPING MOST CONVECTION A BIT MORE NORTH THAN THE NAM AND
SREF THROUGH WEDNESDAY.  THE 00Z SUN ECMWF PROVIDES A COMPROMISE.
DIURNAL CONVECTION TRENDS OF COURSE AND THE INCREASED MOISTURE AND
LOWER HEIGHTS WILL HAVE HIGH TEMPERATURES JUST ABOVE THE NORMALS.
LOOKS LIKE WEDNESDAY HIGHS WILL BE ONLY A DEGREE OR TWO ABOVE
NORMAL.  THIS STALLED OUT FRONTAL BOUNDARY WILL GRADUALLY WASH OUT
OVER THE CAROLINAS THROUGH MID WEEK AS THE NEXT WEAK COLD FRONT
DROPS DOWN FROM THE OHIO VALLEY FROM WEDNESDAY INTO THURSDAY. THIS
DAY TO DAY MAINLY LATE DAY CONVECTION SHOULD HELP THE DROUGHT
SITUATION AND EVENTUALLY MOISTEN MOST LOCATIONS AS THE WEEK
PROGRESSES.  THE CANADIAN MODEL STILL HINTS AT SOME TROPICAL
MOISTURE FROM THE SOUTH...ALTHOUGH TIMING...EXTENT AND LOCATION
CHANGES FROM RUN TO RUN.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 115 PM SUNDAY...A BROAD UPPER TROF AXIS WILL LINGER OVER THE
CWFA THURSDAY THRU SATURDAY...THEN THE SUBTROPICAL HIGH OVER THE
SOUTH-CENTRAL CONUS WILL BEGIN TO EDGE EWD...REASSERTING ITSELF OVER
THE SOUTHEAST STATES LATE NEXT WEEKEND. MODELS IN GOOD AGREEMENT ON
OVERALL PATTERN...AND WITH LITTLE CHANGE FOR OUR WX NEXT SEVERAL
DAYS. A WEAK FRONTAL BNDRY WILL SAG SEWD INTO THE CWFA ON
FRIDAY...WHILE PLENTY OF MOISTURE AND WEAK FLOW REMAINS FROM
PREVIOUS WASHED-OUT FRONT. THIS BNDRY LINGERS THRU SATURDAY...AND
THE 12Z GFS HAS TRENDED MOISTER/FURTHER N WITH THE FRONT IN LINE
WITH THE 00Z ECWMF FOR NEXT WEEKEND. SO WE MAY HAVE ABOVE NORMAL
POPS AND A CATEGORY OR SO WARMER TEMPS THRU AT LEAST NEXT SUNDAY.
DESPITE ABOVE NORMAL COVERAGE OF MAINLY DIURNALLY DRIVEN
CONVECTION...SEVERE THREAT SHUD BE NEAR OR SLIGHTLY BELOW AVERAGE
DUE TO MOIST PROFILES AND SUCH WEAK SHEAR.

&&

.AVIATION /19Z SUNDAY THROUGH FRIDAY/...
AT KCLT...DEWPOINTS ARE HOLDING FIRM IN THE LOWER 70S IN SRLY FLOW.
EARLY CONVECTION IS DEVELOPING ALONG THE MTNS AND FOOTHILLS...BUT
LIGHT STEERING WINDS FROM THE NW AND OUTFLOWS MAY SPREAD CONVECTION
TOWARD THE PIEDMONT THROUGH THE LATE AFTN AND EARLY EVENING HOURS.
HAVE ADVERTISED A CB CLOUD TYPE STARTING AT 20Z. WE COULD NEED TEMPO
THUNDERSTORMS FOR A COUPLE OF HOURS...BUT THE POSSIBLE WINDOW IS
STILL A BIT TOO WIDE TO INCLUDE THAT FOR NOW. 20Z TO 02Z LOOKS LIKE
THE BEST CHANCE RIGHT NOW. WINDS WILL REMAIN S TO SW THROUGH THE
PERIOD AT LESS THAN 10 KT. CONVECTIVE COVERAGE SHOULD BE MORE ROBUST
ON MON WITH THE FRONT PUSHING INTO THE VICINITY...BUT WILL ONLY
MENTION CB CLOUDS FOR NOW THROUGH 18Z MON. MOS SUGGESTS MVFR VSBY IN
BR OR HZ TOWARD DAYBREAK...BUT DEBRIS CLOUDS COULD INHIBIT FORMATION
SO WILL NOT INCLUDE IT IN THE TAF.

ELSEWHERE...SCATTERED CONVECTION HAS DEVELOPED ACROSS THE MTNS EARLY
THIS AFTN...WITH ISOLTED TSTMS FORMING IN THE FOOTHILLS. THINK
COVERAGE WILL SLOWLY SPREAD ACROSS THE FOOTHILLS THROUGH THE LATE
AFTN. HAVE A TEMPO TSRA GROUP AT KAVL 19Z TO 23Z...WITH JUST A CB
MENTION 20Z ONWARD FOR THE FOOTHILL TAF SITES. A NARROW TEMPO TSRA
WINDOW WILL LIKELY BE NEEDED AT SOME POINT AT SOME OF THE FOOTHILL
LOCATIONS AS WELL. EXPECT MAINLY LIGHT S TO SW FLOW THROUGH THE
PERIOD...EXCEPT MORE VARIABLE AND TRENDING NW AT KAVL. OVERNIGHT
DEBRIS CLOUDS/ALTOCU HAVE MADE MORNING VSBY FORECASTS QUITE
CHALLENGING THE PAST FEW DAYS AND TONIGHT WILL BE NO EXCEPTION. GOOD
CONSENSUS EXISTS FOR MVFR VSBY FROM KAND TO KAVL TO KHKY...AND IFR
WILL BE POSSIBLE WHERE ANY HEAVY SHOWERS DEVELOP. CONVECTIVE CHANCES
WILL BE BETTER ON MON...BUT MAINLY AFTER 18Z...SO ONLY CB CLOUDS ARE
MENTIONED FOR MON FOR NOW.

OUTLOOK...A VERY UNSETTLED PATTERN WILL BE IN PLACE ALL WEEK AS ONE
FRONT DISSIPATES IN THE VICINITY AND ANOTHER COLD FRONT ARRIVES FROM
THE NW LATE IN THE WEEK. MORNING MVFR FOG IS LIKELY...AT LEAST IN
THE MTN VALLEYS...WITH SCATTERED TO NUMEROUS AFTN/EVENING TSTMS EACH
DAY.

&&

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

&&

SYNOPSIS...DEO
NEAR TERM...HG
SHORT TERM...DEO
LONG TERM...ARK
AVIATION...HG

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
245 PM EDT SUN JUL 3 2011

GAZ010-017-018-026-028-029-NCZ033-035>037-048>053-056>059-062>065-
068>072-082-501>510-SCZ001>014-019-041845-
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-
245 PM EDT SUN JUL 3 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.

SCATTERED TO NUMEROUS THUNDERSTORMS WILL DEVELOP THIS AFTERNOON
AND EVENING. A FEW SEVERE STORMS ARE POSSIBLE...PRODUCING
DAMAGING WIND GUSTS AND PERHAPS A BRIEF PERIOD OF PENNY TO QUARTER
SIZE HAIL. ANY THUNDERSTORM WILL ALSO BE CAPABLE OF PRODUCING
VERY HEAVY RAINFALL AND OCCASIONAL CLOUD TO GROUND LIGHTNING.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY.

THE COVERAGE OF THUNDERSTORMS WILL INCREASE ACROSS THE REGION ON
MONDAY...ESPECIALLY DURING THE AFTERNOON AND EVENING HOURS. THE
THUNDERSTORMS WILL BE SLOW MOVING...PRODUCING LOCALLY HEAVY
RAINFALL IN AFFECTED AREAS. SOME OF THESE THUNDERSTORMS MAY
BECOME SEVERE...PRODUCING QUARTER SIZE HAIL AND DAMAGING WIND
GUSTS OF 60 MPH OR GREATER. KEEP ABREAST OF THE LATEST FORECASTS
AS YOU CARRY OUT YOUR HOLIDAY PLANS MONDAY AFTERNOON AND EVENING.

.SPOTTER INFORMATION STATEMENT...

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

HG

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
258 PM EDT SUN JUL 3 2011

NCZ051-031930-
SWAIN-
258 PM EDT SUN JUL 3 2011

...A STRONG THUNDERSTORM WILL AFFECT CENTRAL SWAIN COUNTY THROUGH 330
PM EDT...

AT 254 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM 3 MILES SOUTH OF NEWFOUND GAP...OR 9 MILES NORTH
OF BRYSON CITY...MOVING SOUTH AT 5 MPH.

THIS STORM WILL BE NEAR...
  CHEROKEE...

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

LAT...LON 3557 8349 3562 8344 3562 8341 3564 8338
      3564 8336 3550 8328 3547 8332 3547 8335
      3545 8336 3540 8354 3557 8357

RB

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
306 PM EDT SUN JUL 3 2011

GAZ028-SCZ004-010-031930-
ANDERSON-GREATER OCONEE-HART-
306 PM EDT SUN JUL 3 2011

...A STRONG THUNDERSTORM WILL AFFECT NORTHERN HART...SOUTHERN OCONEE
AND WESTERN ANDERSON COUNTIES THROUGH 330 PM EDT...

AT 302 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM 3 MILES SOUTHEAST OF FAIR PLAY...OR 10 MILES
NORTH OF HARTWELL...MOVING SOUTHEAST AT 10 MPH.

THIS STORM WILL BE NEAR...
  REED CREEK...

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

LAT...LON 3432 8299 3446 8307 3450 8305 3459 8293
      3442 8276

RB

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
309 PM EDT SUN JUL 3 2011

NCZ064-031945-
TRANSYLVANIA-
309 PM EDT SUN JUL 3 2011

...A STRONG THUNDERSTORM WILL AFFECT CENTRAL TRANSYLVANIA COUNTY
THROUGH 345 PM EDT...

AT 306 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM 4 MILES NORTHEAST OF ROSMAN...OR 5 MILES SOUTH OF
BREVARD...MOVING SOUTHEAST AT 5 MPH.

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

LAT...LON 3516 8289 3528 8274 3518 8259 3517 8259
      3512 8267 3513 8268 3510 8270 3510 8272
      3507 8276 3507 8278 3508 8277 3508 8281

RB

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
314 PM EDT SUN JUL 3 2011

NCZ056-502-504-031945-
CATAWBA-GREATER BURKE-GREATER CALDWELL-
314 PM EDT SUN JUL 3 2011

...A STRONG THUNDERSTORM WILL AFFECT EASTERN BURKE...NORTHWESTERN
CATAWBA AND SOUTHEASTERN CALDWELL COUNTIES THROUGH 345 PM EDT...

AT 310 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM NEAR LONGVIEW...OR 4 MILES WEST OF HICKORY. THIS
STORM WAS NEARLY STATIONARY.

THIS STORM WILL BE NEAR...
  HICKORY...

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

LAT...LON 3583 8134 3580 8133 3580 8131 3580 8129
      3573 8119 3561 8138 3573 8155 3587 8140

RB

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
343 PM EDT SUN JUL 3 2011

NCZ062-032015-
MACON-
343 PM EDT SUN JUL 3 2011

...A STRONG THUNDERSTORM WILL AFFECT WESTERN MACON COUNTY THROUGH 415
PM EDT...

AT 340 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM 3 MILES NORTHWEST OF RAINBOW SPRINGS...OR 12
MILES WEST OF FRANKLIN...MOVING SOUTHEAST AT 5 MPH.

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

LAT...LON 3525 8361 3514 8336 3499 8348 3499 8353
      3503 8354 3505 8357 3506 8357 3510 8362
      3512 8362 3512 8364 3515 8366 3516 8369

RB

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
345 PM EDT SUN JUL 3 2011

SCZ006-010>012-019-032015-
ABBEVILLE-ANDERSON-GREATER GREENVILLE-GREENWOOD-LAURENS-
345 PM EDT SUN JUL 3 2011

...A STRONG THUNDERSTORM WILL AFFECT EASTERN ANDERSON...NORTHEASTERN
ABBEVILLE...NORTHWESTERN GREENWOOD...SOUTHERN GREENVILLE AND WESTERN
LAURENS COUNTIES THROUGH 415 PM EDT...

AT 344 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM 4 MILES SOUTHWEST OF PRINCETON...OR 17 MILES EAST
OF ANDERSON...MOVING SOUTHEAST AT 5 MPH.

THIS STORM WILL BE NEAR...
  WARE SHOALS...

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

LAT...LON 3447 8212 3430 8231 3447 8250 3461 8235

RB