Special Weather Statement, NWS Greenville-Spartanburg, SC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
315 PM EDT FRI JUL 20 2012

.SYNOPSIS...
A COLD FRONT WILL APPROACH FROM THE NORTHWEST TODAY AND ARRIVE ON
SATURDAY. THE FRONT IS EXPECTED TO STALL OVER THE AREA THROUGH THE
WEEKEND BEFORE DISSIPATING MONDAY.

&&

.NEAR TERM /THROUGH SATURDAY/...
FOR THE REMAINDER OF THE AFTERNOON... ANTICIPATE THE FOCUS OF
STRONGEST CONVECTIVE STORMS WILL EXTEND FROM UPSTATE SC NORTHEAST
ITNO THE SOUTHERN PIEDMONT OF NC. THAT IS ALIGNED WITH RAP SBCAPE
MAXIMUM OF 3000+ J/KG. EFFECTIVE SHEAR IS HIGH ENOUGH OVER PORTIONS
OF THE MOUNTAINS TO SUGGEST SOME ORGANIZATION TO THE
THUNDERSTORMS... BUT THAT AREA IS WEST OF THE MOST UNSTABLE AIR.
PLUS... THE MID-LEVEL VORTICITY MAXIMUM AND BEST VORTICITY ADVECTION
APPEARS TO BE MOVING OUT OVER THE PIEDMONT AS SHORT WAVE TROUGH
ALOFT TRAVELS EASTWARD. SHEAR EAST OF MOUNTAINS NOT PARTICULARLY
IMPRESSIVE AND DOWNDRAFT CAPE IS ONLY AROUND 500 J/KG... SO PULSE
NATURE OF STORMS LIKELY TO PREDOMINATE WITH POSSIBILITY OF SOME
MULTICELL CLUSTERS GETTING TOGETHER.

OTHWERWISE... MODELS IN PRETTY GOOD AGREEMENT REGARDING EVOLUTION OF
MID AND UPPER LEVEL FEATURES THROUGH DAYTIME SATURDAY. AT 500 MB...
LARGE RIDGE PERSISTS OVER WESTERN U.S. WITH BERMUDA HIGH OVER
ATLANTIC. 500 MB TROUGH EXTENDING DOWN EAST COAST INTO OUR CWA
PERSISTS THROUGH SATURDAY... BUT IT WITHDRAWS SLOWLY TO THE NORTH
LEAVING A SHEAR AXIS BEHIND. SHORT WAVE TROUGH CROSSING CWA THIS
AFTERNOON AND THIS EVENING WILL MAINTAIN SURFACE LOW ON FRONTAL
BOUNDARY ACROSS MID-ATLANTIC REGION. LOW WILL BE OFFSHORE SATURDAY
MORNING AND CONTINUE MOVING EAST THEREAFTER. BERMUDA HIGH BUILDS
SLOWLY WESTWARD AS 500 MB HEIGHTS INCREASE JUST A BIT. THIS WILL MAKE
SOUTHWARD MOVEMENT OF FRONTAL BOUNDARY VERY DIFFICULT TO MAINTAIN.
MOIST SOUTHWEST FLOW AHEAD OF THE FRONT ON WEST SIDE OF BERMUDA HIGH
WORKS IN COMBINATION WITH THE WEAK UPPER-LEVEL TROUGH/SHEAR AXIS TO
CONTINUE A MOIST SOUTHWEST FLOW INTO OUR AREA.  FORECASTS FOR
OVERNIGHT AND SATURDAY ACCORDINGLY WILL CARRY POPS FOR SHOWERS AND
THUNDERSTORMS.

&&

.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
AT 230 PM EDT FRIDAY...AN UPPER TROUGH AXIS WILL REMAIN ALONG THE
EAST COAST FROM SATURDAY NIGHT THROUGH MONDAY...WHILE A RIDGE
REMAINS OVER THE PLAINS. A WEAKENING...STALLED SURFACE FRONT WILL
REMAIN OVER OUR AREA THROUGH MONDAY. ALTHOUGH THERE DOES NOT APPEAR
TO BE MUCH ISENTROPIC UPGLIDE OVER THE BOUNDARY...SHORTWAVES MOVING
INTO THE UPPER TROUGH AND OVER THE VICINITY OF THE FRONT WILL
SUPPORT PRECIPITATION THROUGH THE PERIOD...MAXIMIZED WITH GREATER
INSTABILITY DURING DAYLIGHT HOURS. WITHOUT A STRONG LIFTING
MECHANISM...PRECIPITATION AMOUNTS ARE EXPECTED TO BE MODERATE...BUT
SEVERAL DAYS OF RAIN COULD LEAD TO SOME LOCALIZED HYDROLOGICAL
PROBLEMS WITH TIME. MINIMUM TEMPERATURES WILL BE SLIGHTLY ABOVE
NORMAL...AND MAXIMUM TEMPERATURES NEAR NORMAL.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 145 PM FRIDAY...THE CWFA WILL BE IN AN AREA BETWEEN RIDGING TO
THE SOUTH AND WEST AND NW TO SE ORIENTED NRN STREAM FLOW TO THE
NORTH. THE FLOW WILL BE CLOSE ENUF THAT WE SHUD SEE SOME EFFECT FROM
A SERIES OF WEAK SHORT WAVES MOVING THRU THE FLOW. AT THE SFC...A
BACK DOOR COLD FRONT WILL APPROACH THE AREA BUT STALL TO OUR NORTH.
A SERIES OF LOW PRESSURE WAVES WILL MOVE WEST ALONG THE FRONT. OVER
OUR CWFA...A LEE TROF AND COPIOUS LOW LEVEL MOISTURE WILL REMAIN IN
PLACE THRU THE PERIOD. THIS SHUD LEAD TO GENERALLY SCT DIURNAL
CONVECTION EACH DAY. LOWS WILL BE NEARLY STEADY AROUND 5 DEGREES
ABOVE NORMAL. HIGHS START OUT NEARLY 5 DEGREES ABOVE NORMAL THEN
FALL A COUPLE OF DEGREES BY THE END OF THE PERIOD.

&&

.AVIATION /19Z FRIDAY THROUGH WEDNESDAY/...
AT KCLT... SCATTERED SHOWERS AND THUNDERSTORMS WILL CONTINUE IN THE
VICINITY OF THE TERMINAL THROUGH 00Z. THUNDERSTORMS WILL BE CAPABLE
OF STRONG AND GUSTY WIND AND SMALL HAIL. AFTER 02Z... CEILING 4-6 KT
FT LOWERING TO NEAR 2K FT AROUND 12Z. POSSIBILITY EXISTS OF
VISIBILITY NEAR 5 MI IN FOG AROUND SUNRISE. CONSIDERABLE CLOUDINESS
WILL MAKE RADIATIONAL COOLING DIFFICULT... SO VISILITY RESTRICTION
NOT CURRENTLY IN TAF DUE TO UNCERTAINTY. EXCEPT NEAR
THUNDERSTORMS... SURFACE WIND WILL BE SOUTHWEST LESS THAN 10 KT.

REMAINDER TERMINALS... 4-6K FT BROKEN TO OVERCAST. VISIBILITY
UNRESTRICTED EXPECT VICINITY SCATTERED THUNDERSTORMS... MOST
NUMEROUS NEAR KAND... KGMU... AND KGSP. AFT 02Z... SHOWERS AND
THUNDERSTORMS BECOME MORE WIDELY SCATTERED. TOWARD SUNRISE... SOME
LOWER CEILING 2-4 KT FT AND POSSIBILITY OF VISIBILITY RESTRICTION IN
FOG... ESPECIALLY VICINITY KAVL.

OUTLOOK...AS A COLD FRONT STALLS OVER THE AREA...SCATTERED TO
NUMEROUS CONVECTIVE STORMS AND ASSOCIATED RESTRICTIONS WILL PERSIST
THROUGH THE WEEKEND. LATE NIGHT/MORNING FOG AND LOW STRATUS
PROBABILITIES WILL ALSO REMAIN FAIRLY HIGH...ESPECIALLY IN THE MTN
VALLEYS. THUNDERSTORMS WILL BECOME LESS NUMEROUS AS BERMUDA HIGH
BUILDS INTO THE REGION DURING THE FIRST PART OF THE 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...JAT
NEAR TERM...LGL
SHORT TERM...JAT
LONG TERM...RWH
AVIATION...LGL

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
411 AM EDT FRI JUL 20 2012

GAZ010-017-018-026-028-029-NCZ033-035>037-048>053-056>059-062>065-
068>072-082-501>510-SCZ001>014-019-210815-
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-
411 AM EDT FRI JUL 20 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 TO NUMEROUS THUNDERSTORMS ARE EXPECTED ACROSS THE AREA
THIS AFTERNOON AND EVENING. THE MAIN THREATS WITH THESE STORMS WILL
BE LARGE HAIL AND DAMAGING STRAIGHT-LINE WINDS. PERIODS OF HEAVY
RAIN ARE ALSO EXPECTED AND POTENTIAL FLOODING IS A CONCERN...
ESPECIALLY IF SEVERAL STORMS TRAIN OVER THE SAME AREAS.

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

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

NONE.

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
226 PM EDT FRI JUL 20 2012

SCZ014-201915-
CHESTER-
226 PM EDT FRI JUL 20 2012

...A STRONG THUNDERSTORM WILL AFFECT CHESTER COUNTY THROUGH 315 PM
EDT...

AT 224 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM NEAR CORNWELL...OR 8 MILES SOUTH OF CHESTER...
MOVING EAST AT 15 MPH.

THIS STORM WILL IMPACT LOCATIONS NEAR...
  CHESTER...
  BLACKSTOCK...
  RICHBURG...
  FISHING CREEK RESERVOIR...

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

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 3465 8089 3455 8087 3454 8095 3455 8108
      3456 8131 3473 8137 3480 8088 3470 8085

RWH

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
250 PM EDT FRI JUL 20 2012

SCZ009-201915-
YORK-
250 PM EDT FRI JUL 20 2012

...A STRONG THUNDERSTORM WILL AFFECT SOUTHEASTERN YORK COUNTY THROUGH
315 PM EDT...

AT 250 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM NEAR CATAWBA...OR 9 MILES SOUTHEAST OF ROCK
HILL...MOVING EAST AT 15 MPH.

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

LAT...LON 3482 8089 3482 8100 3482 8101 3494 8100
      3495 8086 3484 8086

HG

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
310 PM EDT FRI JUL 20 2012

NCZ082-201945-
UNION-
310 PM EDT FRI JUL 20 2012

...A STRONG THUNDERSTORM WILL AFFECT NORTHERN UNION COUNTY THROUGH
345 PM EDT...

AT 310 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM 4 MILES SOUTHEAST OF INDIAN TRAIL...OR 5 MILES
NORTHWEST OF MONROE...MOVING NORTHEAST AT 15 MPH.

THIS STORM WILL IMPACT LOCATIONS NEAR...
  MONROE...
  UNIONVILLE...

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

LAT...LON 3492 8067 3506 8074 3512 8066 3519 8051
      3519 8049 3517 8046 3518 8037 3503 8029

HG

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
329 PM EDT FRI JUL 20 2012

NCZ071-202000-
MECKLENBURG-
329 PM EDT FRI JUL 20 2012

...A STRONG THUNDERSTORM WILL AFFECT SOUTHERN MECKLENBURG COUNTY
THROUGH 400 PM EDT...

AT 329 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM NEAR PINEVILLE...OR 8 MILES SOUTH OF CENTER CITY
CHARLOTTE...MOVING NORTHEAST AT 10 MPH.

THIS STORM WILL IMPACT LOCATIONS NEAR...
  SOUTHPARK MALL...
  CENTER CITY CHARLOTTE...
  EASTLAND MALL...

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

LAT...LON 3505 8074 3502 8086 3506 8090 3511 8094
      3509 8097 3516 8101 3531 8071 3516 8061

HG

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
346 PM EDT FRI JUL 20 2012

SCZ009-014-202015-
CHESTER-YORK-
346 PM EDT FRI JUL 20 2012

...STRONG THUNDERSTORMS WILL AFFECT NORTHERN CHESTER AND YORK
COUNTIES THROUGH 415 PM EDT...

AT 346 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
STRONG THUNDERSTORMS ALONG A LINE EXTENDING FROM 6 MILES NORTHWEST OF
YORK TO 3 MILES SOUTH OF YORK TO 4 MILES WEST OF LOWRYS...MOVING EAST
AT 15 MPH.

THESE STORMS WILL IMPACT LOCATIONS NEAR...
  MCCONNELLS...
  CLOVER...
  ROCK HILL...

PEA SIZE HAIL...FREQUENT LIGHTNING...WIND GUSTS UP TO 40 MPH...AND
TORRENTIAL RAIN ARE EXPECTED WITH THESE STORMS.

LAT...LON 3480 8105 3471 8142 3494 8133 3508 8141
      3512 8140 3516 8122 3515 8106 3512 8104
      3506 8106 3505 8103 3508 8098 3502 8095

HG

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
402 PM EDT FRI JUL 20 2012

NCZ070-071-SCZ009-202030-
GASTON-MECKLENBURG-YORK-
402 PM EDT FRI JUL 20 2012

...STRONG THUNDERSTORMS WILL AFFECT EASTERN YORK...SOUTHEASTERN
GASTON AND SOUTHWESTERN MECKLENBURG COUNTIES THROUGH 430 PM EDT...

AT 402 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
STRONG THUNDERSTORMS ALONG A LINE EXTENDING FROM 5 MILES SOUTHWEST OF
LAKE WYLIE TO 3 MILES WEST OF ROCK HILL TO 3 MILES NORTHEAST OF
LOWRYS...MOVING NORTHEAST AT 15 MPH.

THESE STORMS WILL IMPACT LOCATIONS NEAR...
  LAKE WYLIE...
  TEGA CAY...
  ROCK HILL...

PEA SIZE HAIL...FREQUENT LIGHTNING...WIND GUSTS UP TO 40 MPH...AND
TORRENTIAL RAIN ARE EXPECTED WITH THESE STORMS.

LAT...LON 3503 8077 3500 8084 3505 8089 3501 8090
      3495 8086 3491 8086 3482 8092 3482 8125
      3491 8116 3513 8120 3529 8088 3508 8072

HG