Special Weather Statement, NWS Greenville-Spartanburg, SC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
235 PM EDT THU JUL 19 2012

.SYNOPSIS...
HIGH PRESSURE WILL WEAKEN AND MOVE SOUTH TODAY. THIS WILL ALLOW
A FRONTAL BOUNDARY OVER THE OHIO VALLEY TO DROP SOUTH...INTO THE
CAROLINAS EARLY SATURDAY. THE FRONT WILL REMAIN OVER OR JUST SOUTH
OF THE REGION THROUGH THE WEEKEND AND DISSIPATE ON MONDAY.

&&

.NEAR TERM /THROUGH FRIDAY/...
AT 230 PM EDT THURSDAY...AN UPPER TROUGH WILL AMPLIFY ALONG THE EAST
COAST TONIGHT AND FRIDAY. A WEAK IMPULSE REACHING THE BASE OF THE
TROUGH IS EXPECTED TO SUPPORT INCREASED CONVECTIVE COVER THIS
AFTERNOON AND EVENING...IN A MOIST UNSTABLE AIR MASS THAT WILL
SUPPORT PULSE SEVERE THUNDERSTORMS WITH LARGE HAIL AND DAMAGING
WIND. STEERING FLOW WILL NOT BE AS WEAK AS EARLIER THIS
WEEK...LIMITING RAINFALL ACCUMULATIONS. CONVECTION WILL GRADUALLY
DIMINISH THIS EVENING WITH THE LOSS OF HEATING. MODEL GUIDANCE
SUGGEST THAT FOG CAN BE EXPECTED ACROSS MUCH OF OF THE AREA BY
DAYBREAK...BUT ONLY FEW MOUNTAIN VALLEYS ARE EXPECTED OT HAVE DENSE
FOG. MINIMUM TEMPERATURES WILL SLIGHTLY ABOVE NORMAL IN A MOIST AIR
MASS UNDER CLOUDS.

A COLD FRONT WILL APPROACH FROM THE NORTH ON FRIDAY...WHILE A PAIR
OF SHORTWAVES MOVES INTO THE BASE OF THE TROUGH. POPS AND QPF WILL
BE SIGNIFICANTLY HIGHER ON FRIDAY IN ADVANCE OF THE FRONT.
INSTABILITY WILL BE SUFFICIENT FOR SEVERE THUNDERSTORMS AGAIN...AND
WITH UNIDIRECTIONAL SHEAR PRESENT...SOME ORGANIZATION IS POSSIBLE...
ESPECIALLY IN THE PIEDMONT. WITH BETTER STEERING FLOW AND MOVING
STORMS...ANY HEAVY PRECIPITATION AMOUNTS WOULD BE FROM TRAINING OR
REPEATING CELLS. MAXIMUM TEMPERATURES WILL BE NEAR NORMAL...AS
ENOUGH BREAK IN CLOUD COVER WILL PERMIT HEATING TO OCCUR.

&&

.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
AS OF 235 PM THURSDAY...SHORT WAVE TROF WITH A SERIES OF ENERGY
MAXES REMAINS OVER THE AREA FRI NITE AND SAT. SFC COLD FRONT BECOMES
STALLED ACROSS THE AREA AS WELL. THE ENERGY MAXES AND RIGHT ENTRANCE
REGION OF THE UPPER JET WILL PROVIDE SOME SYNOPTIC SCALE FORCING AND
UPPER DIVERGENCE WHILE THE FRONT PROVIDES LOW LEVEL CONVERGENCE.
STILL EXPECT A DIURNAL TREND TO THE CONVECTION...BUT THE COPIOUS
MOISTURE AND LARGE SCALE FORCING SHUD KEEP AT LEAST SOME ACTIVITY
GOING MUCH OF THE NIGHT FRI NITE. NUMEROUS COVERAGE IS EXPECTED
AGAIN FOR SATURDAY FOR THE SAME REASONS...AS IS THE LINGERING
COVERAGE OVERNIGHT. HOWEVER...AREAS OUTSIDE OF THE WRN MOUNTAINS
COULD SEE BETTER COVERAGE. LOWS WILL BE NEAR NORMAL...BUT HIGHS WILL
BE BELOW NORMAL WITH MORE CLOUDS EARLIER PRECIP ONSET.

THE SHORT WAVE TROF MOVES EAST OF THE AREA SUNDAY...BUT A SHEAR AXIS
WILL REMAIN IN ITS PLACE. THE FRONT WILL BEGIN TO WASH OUT...BUT A
WEAK BOUNDARY WILL LIKELY LINGER. LOOKS LIKE COVERAGE COULD BE A
LITTLE LESS THAN SATURDAY WITH LESS UPPER SUPPORT...BUT SHUD BE AT
LEAST SCT. LOWS WILL BE A TAD COOLER...BUT HIGHS SHUD REBOUND TO
JUST BELOW NORMAL.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AS OF 215 PM THURSDAY...A WEAK TROF WILL KEEP A SPLIT OVER THE AREA
BETWEEN THE WEST-CENTRAL CONUS RIDGE AND THE BERMUDA RIDGE. AT THE
SFC...A LEE TROF AND COPIOUS LOW LEVEL MOISTURE WILL BE OVER THE
AREA. THIS WILL LEAD TO SCT DIURNAL TSRA AND NEAR TO SLIGHTLY ABOVE
NORMAL TEMPS. ON TUE AND WED...SHORT WAVES MOVING THRU THE NRN
STREAM FLOW HELP CARVE OUT AN UPPER TROF OVER THE EAST COAST. AT THE
SFC...LOW LEVEL MOISTURE AND THE LEE TROF REMAIN IN PLACE FOR TUE
WHILE A BACK DOOR COLD FRONT APPROACHES ON WED. AGAIN...GIVEN THE
MOISTURE...INSTABILITY AND WEAK FORCING...GENERALLY SCT DIURNAL
CONVECTION IS EXPECTED BOTH DAYS. TEMPS WILL INCREASE TO ABOVE
NORMAL BY WED. THE TROF MOVES OFF THE COAST THU AND RIDGING BEGINS
TO REASSERT ITSELF OVER THE SERN US AS MORE SHORT WAVE ENERGY MOVES
ACROSS THE NRN TIER OF THE COUNTRY. THE BACK DOOR FRONT MOVES NORTH
AWAY FROM THE AREA AS WELL. STILL EXPECT ENUF MOISTURE AND
INSTABILITY TO LINGER FOR SCT DIURNAL CONVECTION ONCE AGAIN. TEMPS
WILL FALL A DEGREE OR TWO FOR THU.

&&

.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
AT KCLT...CONVECTION SHOULD HAVE GREATER COVERAGE TODAY AS A WEAK
UPPER IMPULSE MOVES INTO THE AREA. A TEMPO FOR GUSTY WINDS...MVFR
VSBY AND LOW VFR CIG WILL BE CARRIED FOR SEVERAL HOURS THIS
AFTERNOON. GUIDANCE AND TRENDS FAVOR MVFR FOG AROUND DAYBREAK
FRIDAY. GUIDANCE SUPPORTS A VFR CIG...BUT SOME SCATTERED VERY LOW
CLOUDS WILL BE CARRIED IN THE TAF. PRECIPITATION ASSOCIATED WITH AN
APPROACHING COLD FRONT ON FRIDAY SHOULD NOT BE A FACTOR UNTIL AFTER
THIS FORECAST PERIOD.

ELSEWHERE...CONVECTION IS ALREADY FIRING IN THE MOUNTAINS...BUT IS
EXPECTED OT SPREAD INTO THE FOOTHILLS...AND ALL SITES WILL GET A
TEMPO FOR MVFR CONDITIONS IN THUNDERSTORMS THIS AFTERNOON. GUIDANCE
AND RECENT TRENDS FAVOR FOG RETRACTIONS AT DAYBREAK FRIDAY...IFR AT
KAVL...AND MVFR IN THE FOOTHILLS. GUIDANCE FAVORS VFR DAYBREAK CIGS
AT TAF SITES...BUT TRENDS WOULD FAVOR A RESTRICTION AT KAVL...AND AN
IFR CIG WILL BE CARRIED THERE. CONVECTION IS EXPECTED TO GET GOING
EARLIER ON FRIDAY AS A COLD FRONT ARRIVES...BUT ONLY KAVL WILL HAVE
ENOUGH COVERAGE BEFORE THE END OF THE FORECAST PERIOD TO CARRY
THUNDER.

OUTLOOK...PRECIPITATION AND ASSOCIATED RESTRICTIONS REMAIN POSSIBLE
THROUGH THE WEEKEND. FOG AND STRATUS CHANCE WILL BE GREATEST IN THE
MORNING...ESPECIALLY IN THE MTN VALLEYS.

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...JAT
SHORT TERM...RWH
LONG TERM...RWH
AVIATION...JAT

HAZARDOUS WEATHER OUTLOOK...CORRECTED
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
447 AM EDT THU JUL 19 2012

GAZ010-017-018-026-028-029-NCZ033-035>037-048>053-056>059-062>065-
068>072-082-501>510-SCZ001>014-019-200900-
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-
447 AM EDT THU JUL 19 2012

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

.DAY ONE...TODAY AND TONIGHT.

NUMEROUS THUNDERSTORMS WILL DEVELOP ACROSS THE WESTERN CAROLINAS
AND NORTHEAST GEORGIA AGAIN TODAY. THE STORMS ARE EXPECTED TO
INITIALLY DEVELOP ACROSS THE MOUNTAINS...THEN SPREAD INTO THE
FOOTHILLS AND PIEDMONT LATER IN AFTERNOON.

SEVERAL OF THE STORMS TODAY COULD BECOME SEVERE...PRODUCING AREAS
OF WIND DAMAGE AND LARGE HAIL. THE EFFECTS OF HEAVY DOWNPOURS AND
SATURATED SOILS WILL ENHANCE THE THREAT OF FALLING TREES. LOCALLY
VERY HEAVY RAINFALL WILL ACCOMPANY THE STORMS AND FLOODING OF POOR
DRAINAGE AREAS AND A FEW STREAMS MAY DEVELOP. THE STORMS WILL ALSO
PRODUCE FREQUENT CLOUD TO GROUND LIGHTNING.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY.

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

NONE.

14

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
208 PM EDT THU JUL 19 2012

NCZ506-508-191845-
EASTERN MCDOWELL-GREATER RUTHERFORD-
208 PM EDT THU JUL 19 2012

...A COUPLE OF STRONG THUNDERSTORMS WILL AFFECT RUTHERFORD AND
SOUTHEASTERN MCDOWELL COUNTIES THROUGH 245 PM EDT...

AT 205 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM NEAR FERO...OR 6 MILES SOUTH OF MARION...MOVING
SOUTHEAST AT 10 MPH. ANOTHER THUNDERSTORM JUST WEST OF SPINDALE WAS
MOVING TO THE EAST SOUTHEAST AT 5 TO 10 MPH.

THE STORMS WILL IMPACT LOCATIONS NEAR...
  THERMAL CITY...
  DYSARTSVILLE...
  SPINDALE...

PEA SIZE HAIL...AND WIND GUSTS UP TO 40 MPH ARE EXPECTED WITH THE
STORMS.

LAT...LON 3547 8170 3527 8197 3553 8209 3560 8203
      3561 8204 3568 8197

LGL

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
235 PM EDT THU JUL 19 2012

NCZ064-SCZ002-003-191915-
GREENVILLE MOUNTAINS-PICKENS MOUNTAINS-TRANSYLVANIA-
235 PM EDT THU JUL 19 2012

...A STRONG THUNDERSTORM WILL AFFECT NORTHERN PICKENS...NORTHWESTERN
GREENVILLE AND SOUTHERN TRANSYLVANIA COUNTIES THROUGH 315 PM EDT...

AT 235 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM 3 MILES NORTHEAST OF ROCKY BOTTOM...OR 11 MILES
SOUTH OF BREVARD...MOVING SOUTHEAST AT 5 MPH.

THIS STORM WILL IMPACT LOCATIONS NEAR...
  ROCKY BOTTOM...
  TABLE ROCK RESERVOIR...

PEA SIZE HAIL...WIND GUSTS UP TO 40 MPH...AND TORRENTIAL RAIN ARE
EXPECTED WITH THIS STORM.

LAT...LON 3501 8255 3488 8281 3512 8293 3521 8273

HG

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
251 PM EDT THU JUL 19 2012

NCZ064-SCZ001-002-191915-
OCONEE MOUNTAINS-PICKENS MOUNTAINS-TRANSYLVANIA-
251 PM EDT THU JUL 19 2012

...A STRONG THUNDERSTORM WILL AFFECT NORTHEASTERN OCONEE...
NORTHWESTERN PICKENS AND SOUTHWESTERN TRANSYLVANIA COUNTIES THROUGH
315 PM EDT...

AT 251 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM 3 MILES SOUTH OF LAKE TOXAWAY...OR 16 MILES
SOUTHWEST OF BREVARD...MOVING SOUTHEAST AT 5 MPH.

THIS STORM WILL IMPACT LOCATIONS NEAR...
  LAKE JOCASSEE...

DIME SIZE HAIL...WIND GUSTS UP TO 40 MPH AND TORRENTIAL RAIN ARE
EXPECTED WITH THIS STORM.

LAT...LON 3514 8298 3516 8300 3517 8298 3518 8298
      3522 8294 3508 8274 3506 8276 3505 8274
      3505 8273 3491 8291 3502 8302 3503 8301
      3505 8305

HG

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
302 PM EDT THU JUL 19 2012

SCZ001-004-191930-
GREATER OCONEE-OCONEE MOUNTAINS-
302 PM EDT THU JUL 19 2012

...A STRONG THUNDERSTORM WILL AFFECT NORTHERN OCONEE COUNTY THROUGH
330 PM EDT...

AT 303 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM 3 MILES SOUTH OF MOUNTAIN REST...OR 6 MILES
NORTHWEST OF WALHALLA...MOVING EAST AT 10 MPH.

THIS STORM WILL IMPACT LOCATIONS NEAR...
  WALHALLA...
  LAKE KEOWEE...

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

LAT...LON 3488 8321 3488 8320 3489 8321 3492 8317
      3492 8316 3493 8315 3488 8291 3484 8289
      3482 8290 3479 8288 3465 8295 3478 8326

HG

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
313 PM EDT THU JUL 19 2012

NCZ035-036-056-191945-
ALEXANDER-CATAWBA-IREDELL-
313 PM EDT THU JUL 19 2012

...A STRONG THUNDERSTORM WILL AFFECT NORTHEASTERN CATAWBA...
SOUTHEASTERN ALEXANDER AND WESTERN IREDELL COUNTIES THROUGH 345 PM
EDT...

AT 313 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM NEAR LOOKOUT SHOALS LAKE...OR 9 MILES SOUTH OF
TAYLORSVILLE...MOVING EAST AT 10 MPH.

THIS STORM WILL IMPACT LOCATIONS NEAR...
  LOOKOUT SHOALS LAKE...
  STONY POINT...

PEA SIZE HAIL...WIND GUSTS UP TO 40 MPH...AND TORRENTIAL RAIN ARE
EXPECTED WITH THIS STORM.

LAT...LON 3584 8084 3563 8092 3572 8122 3590 8115

HG

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
321 PM EDT THU JUL 19 2012

SCZ002-005-191945-
GREATER PICKENS-PICKENS MOUNTAINS-
321 PM EDT THU JUL 19 2012

...A STRONG THUNDERSTORM WILL AFFECT PICKENS COUNTY THROUGH 345 PM
EDT...

AT 321 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM 4 MILES SOUTH OF ROCKY BOTTOM...OR 9 MILES
NORTHWEST OF PICKENS...MOVING SOUTHEAST AT 5 MPH.

THIS STORM WILL IMPACT LOCATIONS NEAR...
  PICKENS...

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

LAT...LON 3502 8292 3509 8278 3508 8277 3507 8278
      3507 8276 3505 8274 3506 8270 3489 8257
      3479 8281

HG