Special Weather Statement, NWS Greenville-Spartanburg, SC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
423 AM EDT SUN AUG 19 2012

.SYNOPSIS...
A COLD FRONT WILL REMAIN STALLED OVER THE WESTERN CAROLINAS THROUGH
TUESDAY. LATE TODAY A WAVE OF LOW PRESSURE WILL MOVE UP THE FRONTAL
BOUNDARY. ANOTHER WEAK LOW WILL MOVE UP THE FRONT ON MONDAY. BY MID
WEEK THE FRONT WILL GRADUALLY MOVE TO THE COAST ALLOWING WEAK HIGH
PRESSURE TO BUILD INTO THE REGION FROM THE WEST.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 415 AM...THE 12Z GFS H7 QG VERTICAL VELOCITY INDICATES THAT 3
TO 5 MB/HR LIFT WILL MOVE WEST TO EAST ACROSS THE CWA THROUGH 18Z
TODAY. AT 8Z...A BAND OF SHRA AND EMBEDDED TSRA WAS OVER THE UPPER
SAVANNAH RIVER VALLEY. BASED ON RADAR TRENDS...THE BAND MAY REACH
EAST OF THE CLT METRO REGION AS EARLY AS 12Z. I WILL TIME THE BAND
ACROSS THE CWA THIS MORNING. DURING THE AFTERNOON...QG FORCING AND
UPPER DIVERGENCE WILL DECREASE AND THE BAND OF SHRA/TSRA SHOULD
TRACK NE. COVERAGE OVER THE MTNS SHOULD SCATTERED OUT THIS AFTERNOON
AND CONTINUE TO DECREASE INTO THE EARLY EVENING. IN FACT...THE NAM
DEVELOPS A WELL DEFINED WAVE OVER THE CENTRAL CAROLINAS THIS
AFTERNOON...RESULTING IN DOWNSLOPE FLOW ACROSS THE CWA THROUGH THIS
EVENING.

TEMPERATURES FORECAST WILL BE CHALLENGING TODAY. I WILL EXPECT
STEADY TEMPERATURES THIS MORNING UNDER WIDESPREAD RAIN AND LIGHT NE
WINDS. THIS AFTERNOON...DECREASING RAINFALL COVERAGE AND RATES
SHOULD ALLOW TEMPERATURES TO WARM. I WILL KEEP AFTERNOON
TEMPERATURES LIMITED TO NEAR 80 DEGREES.

TONIGHT...GFS H7 QG VERTICAL VELOCITY GRADUALLY INCREASE ACROSS THE
FORECAST AREAS AS THE TROF AXIS APPROACHES THE REGION. SCATTERED
LIGHT RAIN MAY GRADUALLY INCREASE ACROSS THE REGION AFTER MIDNIGHT.
LOW TEMPERATURES ARE FORECAST TO RANGE FROM THE U50S ACROSS THE MTNS
TO MID 60S EAST.

&&

.SHORT TERM /MONDAY THROUGH WEDNESDAY/...
AS OF 315 AM SAT...MODEL AGREEMENT IN THE HANDLING OF THE NEXT
RATHER SUBTLE SHORT WAVE FEATURE TO INDUCE SFC CYCLOGENESIS OVER
THE REGION ISN/T GREAT. DIFFERING SOLUTIONS ABOUND. HPC FAVORED AN
SREF/GFS SOLUTION FOR THIS WAVE WHICH BRINGS PCPN BACK ACROSS THE
FORECAST AREA DURING THE DAY ON MONDAY AND INTO MONDAY NIGHT. THE
SREF ACTUALLY HAS RATHER HEAVY PCPN OVER THE FOOTHILLS AND PIEDMONT
WITH AMOUNTS RANGING FROM 0.50-1.00 INCH EAST OF THE MTNS...WITH THE
HEAVIEST TOTALS OVER THE ERN ZONES. THE OPERATIONAL NAM CONTINUES TO
BE MUCH DRIER...THOUGH IT/S STRUGGLED WITH GENERATING PCPN FOR A
WHILE NOW. THE SREF LOOKS LIKE A BETTER SOLUTION AND IT/S IN ROUGH
AGREEMENT WITH THE GFS. THEREFORE...POPS HAVE BEEN INCREASED TO
LIKELY OVER MUCH OF THE FA MONDAY AFTN AND MONDAY NIGHT. THE GFS HAS
MODEST INSTABILITY AND A FEW TSTMS ARE POSSIBLE AND THUNDER HAS BEEN
RETAINED IN THE GRIDS.

PCPN SHOULD TAPER OFF MONDAY NIGHT. HOWEVER...ANOTHER WAVE MAY
DEVELOP ALONG THE FRONT DURING THE DAY ON TUE. THIS FEATURE LOOKS
WEAKER...AND THE WITH THE UPPER TROPOSPHERIC JET CORE AS WELL AS THE
STRONGER LLVL WIND FIELDS GRADUALLY PUSHING EAST...I/D EXPECT THE
BULK OF THE PCPN TO BE CLOSER TO THE COAST. EVEN SO...THE TRUE SFC
FRONT LOOKS TO HANG UP OVER THE MTNS AND THE ATMOSPHERE WILL BE
UNSTABLE ENOUGH TO SUPPORT SCT SHRA/TSTMS IN THE AFTN HOURS AS THE
FORCING IMPROVES. I SUPPOSE IT COULD BE A LITTLE HEAVIER OR A LITTLE
MORE STRATIFORM IN NATURE...BUT CONFIDENCE IN THE PATTERN EVOLUTION
ON TUE IS QUITE LOW AND I WON/T GET TOO CUTE. THE FRONT SHOULD
FINALLY PUSH EAST OF THE REGION ON WEDNESDAY WITH A DRY DAY EXPECTED
WITH TEMPERATURES A DEGREE OR TWO BELOW NORMAL.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/...
AS OF 330 AM SUN...THE FORECAST AREA LOOKS TO BE UNDER WEAK SHORT
WAVE RIDGING THURSDAY AND FRIDAY. WE HAVE LOW CHANCE POPS OVER THE
MTNS AND A DRY FORECAST ELSEWHERE BOTH DAYS. THIS MIGHT BE A LITTLE
OVER DONE...BUT I/LL LET IT FLY. BY SATURDAY THE GFS AND ECMWF BRING
A STRONGER SRN STREAM SHORT WAVE TOWARD THE REGION. TIMING OF THIS
FEATURE IS QUITE IFFY...AND IT COULD EASILY BE A DAY FASTER OR
SLOWER THAN PROGGED. WE HAVE A LITTLE GREATER CHANCE POP COVERAGE ON
SATURDAY AND THIS SEEMS REASONABLE AS WELL. I/VE WARMED TEMPS A
LITTLE...BLENDING IN THE LATEST TEMPERATURE GUIDANCE FROM THE MAV.
THIS BRINGS TEMPS UP TO NEAR NORMAL VALUES FOR THIS TIME OF YEAR.

&&

.AVIATION /09Z SUNDAY THROUGH THURSDAY/...
AT KCLT AND ELSEWHERE...LATEST RADAR IMAGES SHOW A BAND OF SHOWERS AND
EMBEDDED TSRA MOVE NE ACROSS THE UPPER SAVANNAH RIVER VALLEY.
OBSERVATIONS UNDER THE BAND INDICATE CEILINGS RANGING FROM LIFR TO
VFR. THE CONSENSUS OF GUIDANCE SUPPORTS LOWERING CLOUD BASES TO
IFR...ESPECIALLY WITH THE ARRIVAL OF THE BAND OVER THE TERMINALS
THIS MORNING. A WEAK COLD AIR DAMMING PATTERN WILL LIKELY SET UP THIS
MORNING ACROSS THE REGION AS FORCING STRENGTHENS AND RAIN SHIELD
EXPANDS. I WILL FORECAST LIGHT NNE WINDS AND CEILINGS IFR TO MVFR
THROUGH THE DAY. IN ADDITION...PERIODS OF MVFR VIS IN RAIN IS
EXPECTED AROUND MID DAY. RAINFALL WILL LIKELY DECREASE THIS EVENING
AS FORCING LIFTS NORTHEAST...CEILINGS MAY GRADUALLY IMPROVE THROUGH
THE EVENING.

OUTLOOK...AN AREA OF LOW PRESSURE DEVELOPING ALONG STALLED FRONT IS
EXPECTED TO RESULT IN AT LEAST SCATTERED SHOWERS AND ISOLATED TS
CONTINUING INTO SUNDAY NIGHT AND EARLY MONDAY. A GRADUAL DRYING
TREND IS EXPECTED TOWARD THE MIDDLE OF 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...MCAVOY
NEAR TERM...NED
SHORT TERM...MCAVOY
LONG TERM...MCAVOY
AVIATION...NED

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
1213 AM EDT SUN AUG 19 2012

GAZ010-017-018-026-028-029-NCZ033-035>037-048>053-056>059-062>065-
068>072-082-501>510-SCZ001>014-019-200415-
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-
1213 AM EDT SUN AUG 19 2012

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

.DAY ONE...TONIGHT.

ISOLATED THUNDERSTORMS WILL AFFECT WESTERN NORTH CAROLINA THROUGH
THE EARLY MORNING HOURS. BRIEF HEAVY RAIN...GUSTY WINDS AND CLOUD
TO GROUND LIGHTNING WILL BE THE MAIN THREAT FROM THESE STORMS.

LATER TONIGHT...ADDITIONAL THUNDERSTORMS ARE EXPECTED TO MOVE INTO
THE SOUTHWEST AND CENTRAL MOUNTAINS OF NORTH CAROLINA AS WELL AS
THE WESTERN UPSTATE AND NORTHEAST GEORGIA. SOME OF THESE STORMS
WILL PRODUCE LOCALLY HEAVY RAIN.

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

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

NONE.

MCAVOY

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
158 AM EDT SUN AUG 19 2012

NCZ057-190645-
ROWAN-
158 AM EDT SUN AUG 19 2012

...A STRONG THUNDERSTORM WILL AFFECT EASTERN ROWAN COUNTY THROUGH 245
AM EDT...

AT 154 AM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM 3 MILES SOUTH OF SALISBURY...MOVING NORTHEAST AT
20 MPH.

* OTHER LOCATIONS AFFECTED INCLUDE BUT ARE NOT LIMITED TO HIGH ROCK
  LAKE...SPENCER...SALISBURY...GRANITE QUARRY...FAITH AND CRAVEN.

PENNY SIZE HAIL...AND WIND GUSTS OF 40 TO 50 MPH ARE EXPECTED WITH
THIS STORM.

LAT...LON 3554 8050 3564 8059 3576 8048 3576 8047
      3574 8045 3573 8042 3573 8034 3571 8032
      3568 8033 3566 8030 3563 8028

MCAVOY

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
245 AM EDT SUN AUG 19 2012

GAZ010-017-018-026-028-190730-
FRANKLIN-HABERSHAM-HART-RABUN-STEPHENS-
245 AM EDT SUN AUG 19 2012

...STRONG THUNDERSTORMS WILL AFFECT FRANKLIN...HABERSHAM...SOUTHERN
RABUN...STEPHENS AND WESTERN HART COUNTIES THROUGH 330 AM EDT...

AT 240 AM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
STRONG THUNDERSTORMS ALONG A LINE EXTENDING FROM 4 MILES SOUTH OF
CAMP COLEMAN LAKE TO WESTGATE PARK...MOVING NORTHEAST AT 30 MPH.

* OTHER LOCATIONS AFFECTED INCLUDE BUT ARE NOT LIMITED TO LAKE
  RABUN...NACOOHE LAKE...WHITWORTH...VANNA...TURNERVILLE...TOCCOA...
  TALLULAH FALLS...ROYSTON...MOUNT AIRY...MARTIN...LAVONIA...
  LAKEMONT...HOLLYWOOD...FRANKLIN SPRINGS...EASTANOLEE...DEMOREST...
  CORNELIA...CLARKESVILLE...CARNESVILLE...CANON...BOYDVILLE...
  BOWERSVILLE...BALDWIN AND AVALON.

WIND GUSTS UP TO 40 MPH ARE EXPECTED WITH THESE STORMS.

HEAVY RAINS MAY FLOOD AREAS WITH POOR DRAINAGE...SUCH AS DITCHES AND
UNDERPASSES. AVOID THESE AREAS AND DO NOT CROSS FLOODED ROADS. WATER
LEVELS OF SMALL STREAMS AND RIVERS MAY ALSO RISE RAPIDLY. SEEK HIGHER
GROUND IF THREATENED BY FLOOD WATERS.

LAT...LON 3422 8308 3426 8312 3424 8319 3426 8331
      3422 8335 3426 8334 3432 8340 3446 8340
      3449 8354 3443 8362 3450 8367 3454 8362
      3465 8367 3472 8364 3485 8331 3470 8335
      3461 8317 3450 8305 3424 8292 3421 8299

MCAVOY

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
346 AM EDT SUN AUG 19 2012

GAZ018-026-028-SCZ004-005-010-190830-
ANDERSON-FRANKLIN-GREATER OCONEE-GREATER PICKENS-HART-STEPHENS-
346 AM EDT SUN AUG 19 2012

...A STRONG THUNDERSTORM WILL AFFECT NORTHEASTERN FRANKLIN...NORTHERN
ANDERSON...NORTHERN HART...SOUTHEASTERN STEPHENS...SOUTHERN OCONEE
AND SOUTHWESTERN PICKENS COUNTIES THROUGH 430 AM EDT...

AT 342 AM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM 4 MILES EAST OF WHITWORTH...OR 9 MILES NORTHWEST
OF HARTWELL...MOVING NORTHEAST AT 30 MPH.

* OTHER LOCATIONS AFFECTED INCLUDE BUT ARE NOT LIMITED TO LAKE
  HARTWELL...WHITWORTH...REED CREEK...LAVONIA...HARTWELL...AVALON...
  TOWNVILLE...SIX MILE...SENECA...SANDY SPRINGS...SADLERS CREEK STATE
  PARK...PENDLETON...OAKWAY...FAIR PLAY...CLEMSON...CENTRAL AND
  ANDERSON.

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

HEAVY RAINS MAY FLOOD AREAS WITH POOR DRAINAGE...SUCH AS DITCHES AND
UNDERPASSES. AVOID THESE AREAS AND DO NOT CROSS FLOODED ROADS. WATER
LEVELS OF SMALL STREAMS AND RIVERS MAY ALSO RISE RAPIDLY. SEEK HIGHER
GROUND IF THREATENED BY FLOOD WATERS.

LAT...LON 3431 8299 3443 8313 3448 8318 3453 8324
      3482 8282 3454 8252

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
434 AM EDT SUN AUG 19 2012

SCZ006-010-012-190915-
ANDERSON-GREATER GREENVILLE-LAURENS-
434 AM EDT SUN AUG 19 2012

...A STRONG THUNDERSTORM WILL AFFECT NORTHEASTERN ANDERSON...
NORTHWESTERN LAURENS AND SOUTHEASTERN GREENVILLE COUNTIES THROUGH 515
AM EDT...

AT 428 AM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM 3 MILES SOUTHWEST OF WILLIAMSTON...OR 9 MILES
NORTHEAST OF ANDERSON...MOVING NORTHEAST AT 35 MPH.

THIS STORM WILL IMPACT LOCATIONS NEAR...
  PIEDMONT...
  WHITE HORSE ROAD AT I-85...
  DONALDSON CENTER...
  SIMPSONVILLE...
  FOUNTAIN INN...
  FIVE FORKS...

WIND GUSTS OF 40 TO 50 MPH ARE EXPECTED WITH THIS STORM.

HEAVY RAINS MAY FLOOD AREAS WITH POOR DRAINAGE...SUCH AS DITCHES AND
UNDERPASSES. AVOID THESE AREAS AND DO NOT CROSS FLOODED ROADS. WATER
LEVELS OF SMALL STREAMS AND RIVERS MAY ALSO RISE RAPIDLY. SEEK HIGHER
GROUND IF THREATENED BY FLOOD WATERS.

FREQUENT LIGHTNING IS OCCURRING WITH THIS STORM. IF OUTDOORS...TRY TO
GET INDOORS OR INTO A HARD TOPPED VEHICLE. OTHERWISE...STAY AWAY FROM
OPEN AREAS AND ISOLATED HIGH OBJECTS SUCH AS TREES. WHEN INDOORS...
STAY AWAY FROM WINDOWS AND DOORS AND AVOID USING WIRED ELECTRONIC
DEVICES. TRY TO UNPLUG UNNECESSARY APPLIANCES BEFORE THE STORM
APPROACHES.

LAT...LON 3469 8267 3491 8224 3490 8222 3486 8223
      3477 8213 3475 8212 3474 8208 3471 8206
      3470 8207 3467 8202 3445 8246

MCAVOY