Special Weather Statement, NWS Greenville-Spartanburg, SC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
237 AM EDT TUE JUL 10 2012

.SYNOPSIS...
A COLD FRONT WILL BECOME STATIONARY ACROSS THE CAROLINAS AND
GEORGIA...AND WILL REMAIN IN THE AREA THROUGH FRIDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF EARLY TUESDAY MORNING...CONVECTION CONTINUES TO FILL IN ACROSS
THE NC FOOTHILLS AND NC PIEDMONT...WHERE COVERAGE IS NUMEROUS AS OF
05Z. A SIMILAR TREND WAS NOTED ACROSS THE LAKELANDS. A FEW STORMS
HAVE ALSO FIRED NEAR THE BLUE RIDGE SC/NC BORDER. THE UPSTATE AND NE
GEORGIA MAY CONTINUE TO FILL IN THROUGH 09Z AS THAT AREA HAS THE
GREATEST REMAINING BUOYANCY. MEANWHILE...OTHER CONVECTION ACROSS SE
TN/N GA CONTINUES TO DEVELOP TOWARD THE NC MTNS. EXPECT SEVERAL
UPDATES TO MODIFY PRECIP CHANCES THROUGH SUNRISE. TEMPS ARE HOLDING
IN DECENT SHAPE.

FOR TODAY...DEEP MOISTURE IS IN PLACE WITH PW IN THE 1.5 TO 2 INCH
RANGE AND A FAVORABLE MID/UPPER LEVEL ENVIRONMENT WITH THE RIGHT
ENTRANCE REGION OF THE JET MOVING OVERHEAD AND THE TROF AXIS TO THE
WEST. MEANWHILE...A WEAK SURFACE FRONT WILL REMAIN LAID OUT ACROSS
TN AND THE CAROLINAS. THIS SHOULD TRANSLATE TO NUMEROUS SHOWERS AND
THUNDERSTORMS ONCE HEATING UNLEASHES CAPE GREATER THAN 1500 J/KG IN
AN UNCAPPED AIR MASS. HOWEVER...CONFIDENCE IS TEMPERED BY THE
FAILURE OF YESTERDAYS FCST TO WORK OUT. FOR THAT REASON...HAVE KEPT
PRECIP CHANCES LIMITED TO LIKELY...IN SPITE OF CATEGORICAL SREF. THE
HIGH PRECIP CHANCES ONLY GRADUALLY TAPER OFF TO THE CHANCE RANGE
LATE TONIGHT AS THE BOUNDARY LAYER COOLS...BUT SOME CONVECTION IS
LIKELY TO PERSIST THROUGH DAYBREAK WEDNESDAY SIMILAR TO WHAT IS
ONGOING EARLY TUESDAY MORNING. TEMPS WERE NUDGED TOWARD A GUIDANCE
BLEND...SO SOME WARMING INTO THE 90S SHOULD BE EXPECTED OVER THE
SOUTH WHERE PRECIP MIGHT BEGIN LATER IN THE DAY. HAVE BUMPED MIN
TEMPS UP A BIT TONIGHT WITH CLOUD COVER. SEVERE STORMS ARE CERTAINLY
A POSSIBILITY...BUT THE ENVIRONMENT SHOULD NOT BE AS RICH IN DCAPE
AS IN PREVIOUS DAYS...SO THAT WILL BE A LIMITING FACTOR. SLIGHTLY
BETTER SHEAR MAY ORGANIZE STORMS MORE INTO MULTICELL CLUSTERS. WILL
HAVE TO MIND PERSISTENT OR TRAINING CELLS FOR INCREASING FLOOD
THREAT THROUGH MID WEEK.

&&

.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AT 3 AM EDT TUESDAY...A POSITIVELY TILTED UPPER TROUGH WILL EXTEND
FROM EASTERN CANADA TO THE LOWER MS RIVER VALLEY ON WEDNESDAY. BY
THURSDAY THE NORTHERN AND SOUTHERN STREAM ARE OUT OF PHASE...WITH
THE CANADIAN PORTION OF THE TROUGH PROGRESSING...AND THE PORTION IN
THE USA REMAINING IN PLACE. MEANWHILE...A WESTERN ATLANTIC UPPER
RIDGE BEGINS TO BUILD BACK TO THE WEST...RISING HEIGHTS OVER THE
CAROLINAS AND GEORGIA. A STATIONARY FRONT WILL REMAIN IN OUR AREA ON
WEDNESDAY. THE MODELS DIFFER ON THE EXACT LOCATION OF THE BOUNDARY.
ON THURSDAY A SURFACE WAVE DEVELOPS ON THE FRONT IN THE LOWER MS
RIVER VALLEY...AND THE FRONT STARTS TO MOVE NORTH. AGAIN...THE
MODELS DIFFER ON THE LOCATION OF THE FRONT AS MIT MOVES NORTH. THIS
BOUNDARY WILL SERVE AS A FOCUS FOR PRECIPITATION...AND MODEL TIME
HEIGHTS SHOW DEEP MOISTURE THROUGH WEDNESDAY AND THURSDAY. UPPER
LEVEL IMPULSES LEAVING THE TROUGH TO THE WEST WILL MOVE UP THE
SOUTHERN APPALACHIANS...MAKING THAT THE AREA EXPECTED TO RECEIVE THE
GREATEST PRECIPITATION COVERAGE AND AMOUNTS. ADDING TO THIS
SCENARIO...THE NAM INCREASES SOUTHEASTERLY UPSLOPE FLOW ON THURSDAY.
WITH UNCERTAINTY ON THE FRONTAL LOCATION...FORECAST PRECIPITATION
AMOUNTS WILL BE MODERATE. MAXIMUM TEMPERATURES WILL BE BELOW NORMAL
UNDER CLOUDS COVER...AND MINIMUM TEMPERATURES SLIGHTLY ABOVE NORMAL
IN ELEVATED MOISTURE.

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
AT 3 AM EDT TUESDAY...A WEAKENING UPPER TROUGH WILL LING OVER THE
CENTRAL AND SOUTHERN MS RIVER VALLEY INTO MONDAY...WHILE UPPER
RIDGING REMAINS OFF THE SOUTHEAST COAST.  UPPER IMPULSES LEAVING THE
TROUGH MAY ADD SUPPORT FOR CONVECTION ON FRIDAY AND SATURDAY...
ESPECIALLY IN THE MOUNTAINS. ON SUNDAY THE BACK BUILDING ATLANTIC
RIDGE KEEPS THE IMPULSE TRACK WELL TO OUR NORTH. THE GFS  RIDGE
FLATTENS THE RIDGE ON MONDAY...AND TAKES A SHORTWAVE TO THE
APPALACHIANS....WHILE THE ECMWF RIDGE HOLD UPPER SYSTEMS AT BAY.
THIS OLD STATIONARY FRONT FROM NC TO THE GULF STATES BEGINS LIFTING
NORTH AS A WARM FRONT ON FRIDAY REACHING THE OH VALLEY ON SATURDAY.
THIS PUTS OUR AREA IN A WARM AND HUMID AIR MASS FROM FRIDAY THROUGH
MONDAY...BUT WITH THE RIDGE CENTER FAR ENOUGH WEST TO WARMTH AT THE
MID LEVELS THAT MIGHT CAP CONVECTION. CHANCE POPS WILL BE
CARRIED...HIGHEST IN THE WEST WHERE IMPULSES AFFECT THE MOUNTAINS
HEIGHTS ALOFT ARE LOWEST...AND OROGRAPHIC EFFECTS ARE POSSIBLE.
MAXIMUM TEMPERATURES WILL TREND UPWARD AS HEIGHTS RISE ALOFT.
MINIMUM TEMPERATURES WILL REMAIN NEAR OR SLIGHTLY ABOVE NORMAL DUE
TO MOISTURE.

&&

.AVIATION /07Z TUESDAY THROUGH SATURDAY/...
AT KCLT...WILL CONTINUE TO WATCH SHOWERS AND A FEW STORMS DEVELOPING
ACROSS THE NC FOOTHILLS AND NW PIEDMONT THROUGH THE PRE-DAWN HOURS.
CANNOT RULE OUT AN OUTFLOW BOUNDARY TRIGGERING MORE CONVECTION NEAR
THE AIRFIELD AND THIS WILL BE HANDLED WITH AMENDMENTS. OTHERWISE...
SOME LOW CLOUDS WILL BE IN THE VICINITY BUT HAVE KEPT TAF VFR. WIND
WILL BE LIGHT FROM THE NE. ON TUESDAY...EXPECT CONVECTIVE CLOUDS TO
DEVELOP AS SOON AS HEATING BEGINS IN MID MORNING. THE MOIST AND
UNCAPPED AIRMASS SHOULD EASILY CONVECT...SO A PROB30 WAS STARTED AS
SOON AS PERMITTED AT 15Z. THERE WILL BE AT LEAST ONE THUNDERSTORM
TODAY SO HAVE INDICATED THAT DURING THE AFTERNOON PERIOD. THE REST
OF THE TAF WAS KEPT VFR BUT THERE COULD EASILY BE ANOTHER STORM IN
THE EVENING.

ELSEWHERE...TSTMS CONTINUE IN THE VICINITY OF KHKY AND A TEMPO MVFR
WAS KEPT THERE FOR THE FIRST TWO HOURS THROUGH 08Z. OTHERWISE...A
SHOWER OR THUNDERSTORM COULD DEVELOP AT ANY TIME. AFTERNOON IS THE
FAVORED TIME...AND MOST TAFS GET AT LEAST A TEMPO PERIOD AND PROB30
PERIOD TO INDICATE THIS. KAVL COULD SEE ANOTHER BRIEF PERIOD OF MVFR
VISIBILITY AROUND SUNRISE. WIND SHOULD BE LIGHT...BUT VARIABLE
DEPENDING ON LOCATIONS OF STORMS.

OUTLOOK...SHRA/TSRA AREA EXPECTED TO BECOME NUMEROUS AGAIN ON
WEDNESDAY WITH A STALLED FRONT ACROSS THE CAROLINAS AND A WEAK UPPER
TROUGH TO OUR WEST. THIS WILL BRING OCCASIONAL MVFR/IFR RESTRICTIONS
AROUND STORMS. THIS COULD OCCUR AGAIN THURSDAY AND FRIDAY. AREAS OF
MORNING FOG/STRATUS ARE POSSIBLE...ESP IN THE MTN VALLEYS AND WHERE
RAIN FALLS.

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...PM
SHORT TERM...JAT
LONG TERM...JAT
AVIATION...PM

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
325 PM EDT MON JUL 9 2012

GAZ010-017-018-026-028-029-NCZ033-035>037-048>053-056>059-062>065-
068>072-082-501>510-SCZ001>014-019-101930-
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-
325 PM EDT MON JUL 9 2012

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 CONTINUE TO DEVELOP ACROSS THE
REGION INTO THIS EVENING. SOME OF THESE STORMS MAY BECOME
SEVERE...PRODUCING LARGE HAIL AND DAMAGING WIND GUSTS.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY.

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.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
307 AM EDT TUE JUL 10 2012

SCZ012-019-100745-
GREENWOOD-LAURENS-
307 AM EDT TUE JUL 10 2012

...A STRONG THUNDERSTORM WILL AFFECT NORTHEASTERN GREENWOOD AND
SOUTHERN LAURENS COUNTIES THROUGH 345 AM EDT...

AT 302 AM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM NEAR CORONACA...OR 6 MILES NORTHEAST OF
GREENWOOD...MOVING EAST AT 10 MPH.

THIS STORM WILL IMPACT LOCATIONS NEAR...
  LAKE GREENWOOD...
  CROSS HILL...

SMALL HAIL...WIND GUSTS OF 40 TO 50 MPH AND TORRENTIAL RAIN ARE
EXPECTED WITH THIS STORM.

FREQUENT LIGHTNING IS 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 3434 8221 3444 8184 3434 8181 3434 8183
      3431 8186 3430 8189 3424 8190 3420 8194
      3419 8192 3418 8192 3416 8217

07