Special Weather Statement, NWS Greenville-Spartanburg, SC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
557 PM EDT WED AUG 8 2012

.SYNOPSIS...
BERMUDA HIGH PRESSURE WILL BUILD IN FROM THE SOUTHEAST TONIGHT AND
REMAINS THROUGH THURSDAY. A COLD FRONT WILL PUSH ACROSS THE AREA
FROM THE WEST LATE FRIDAY. DRY HIGH PRESSURE WILL THEN BUILD BEHIND
THE FRONT OVER THE WEEKEND.

&&

.NEAR TERM /THROUGH THURSDAY/...
AS OF 550 PM...A COUPLE CLUSTERS OF STRONG TO SEVERE STORMS CONTINUE
TO SLOWLY MOVE SOUTHWARD ACROSS THE FORECAST AREA. ONE IS OVER THE
NE GA ZONES...ONE OVER THE NE PART OF THE UPSTATE...AND CONVECTION
IS STARTING TO POP AGAIN UP NEAR STATESVILLE. THERE ARE SEVERAL
AREAS OF HIGH CAPE REMAINING ACROSS THE FA AND THERE IS STILL A
CHANCE FOR ADDITIONAL SEVERE WEATHER OVER THE NEXT HOUR OR TWO. AS
THE PREVIOUS SHIFT NOTED...THINGS SHOULD QUIET DOWN TOWARD SUNSET.
THE POP AND WEATHER GRIDS HAVE BEEN UPDATED AS WELL AS POSSIBLE TO
ACCOUNT FOR CURRENT CONVECTIVE TRENDS.

AS OF 230 PM...EARLY AFTN CONVECTION DEVELOPING AHEAD OF A WEAK
SHORTWAVE OVER THE NC FOOTHILLS HAS PUT DOWN SOME OUTFLOWS ACROSS
THE NC PIEDMONT. ADDITIONAL CONVECTION IS DEVELOPING ALONG THE ERN
SLOPES OF THE MOUNTAINS AS A SECONDARY SHORTWAVE ARRIVES...AND WHERE
LOW LEVEL CONVERGENCE IS STRONGEST. THIS ACTIVITY SHOULD ALSO SPREAD
EWD GIVEN THE STEERING FLOW. POPS HAVE BEEN RAISED THROUGHOUT FOR
THE LATE AFTN HOURS. 3000 TO 4000 J/KG SFC BASED CAPE VALUES ARE
INDICATED ON LAPS ANALYSIS...AND THE MID LEVEL DRY PUNCH ALONG WITH
DCAPE VALUES AROUND 1000 J/KG SHOULD YIELD A FEW SEVERE TSTMS WITH
ANY 55 DBZ CORES ABOVE 25 KFT. HEAVY RAINFALL ON SATURATED GROUND
COULD ALSO CREATE ISOLD HYDRO ISSUES...BUT STORMS SHOULD MOVE A BIT
MORE TODAY COMPARED TO THE PAST FEW DAYS.

CONVECTION SHOULD DIE OUT FAIRLY QUICKLY WITH THE LOSS OF HEATING
THIS EVENING...WITH JUST DEBRIS CLOUDS EARLY...AND POSSIBLY LOW
CLOUDS AND FOG LATE. GUIDANCE REMAINS MIXED ON HOW DENSE THE FOG MAY
GET...BUT MTN VALLEYS SHOULD SEE THE WORST VSBY.

A MORE PROMINENT SHORTWAVE MOVING AROUND THE DEVELOPING UPPER
MIDWEST LOW PRESSURE ON THU WILL APPROACH THE REGION BUT REMAIN W OF
THE MTNS THROUGH THE LATE DAY. THE MAIN IMPACT OF THIS FEATURE
THROUGH THE NEAR TERM WILL BE BACKING SW FLOW AND SLOWLY DEEPENING
MOISTURE OVER THE REGION. SCATTERED AFTERNOON CONVECTION IS EXPECTED
WITH THE BEST POPS OVER THE MTNS AND SW SECTIONS. MAXES WILL BE
SIMILAR TO WED...PERHAPS A DEGREE HIGHER IN THE ERN PIEDMONT.

&&

.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...
AS OF 120 PM WEDNESDAY...AT LEAST SCATTERED CONVECTION IS EXPECTED
TO LINGER WELL INTO THE OVERNIGHT THURSDAY/EARLY FRIDAY. THIS IS A
RESULT ON AN INCREASINGLY MOIST WAA PATTERN IN THE WARM SECTOR OF AN
ANOMALOUSLY STRONG CYCLONE...AS WELL AS A PRECURSOR SHORT WAVE
TROUGH THAT THE MODELS DRIFT ACROSS THE AREA THURSDAY NIGHT.

FOR FRIDAY...THERE IS STILL QUITE A BIT OF UNCERTAINTY REGARDING THE
SEVERE WEATHER THREAT. IT STILL APPEARS AS IF THERE COULD BE FAIRLY
EXTENSIVE CLOUD COVER...AS WELL AS SHOWERS EARLY IN THE DAY. AS
SUCH...THE SHORT RANGE MODELS HAVE BACKED OFF ON THE DEGREE OF
FRIDAY PM INSTABILITY DURING THE PAST 24 HOURS. DESPITE THE
STRENGTHENING UPPER FLOW...THE UNIDIRECTIONAL NATURE OF THE FORECAST
WIND PROFILES IS YIELDING MODEST AT BEST SHEAR. IN ADDITION...THE
BETTER DEEP LAYER FORCING WILL PASS NORTH OF THE AREA...ALTHOUGH
FAIRLY STRONG LOW LEVEL FORCING IS EXPECTED ALONG THE FRONT PROPER
DURING THE EVENING. TAKING ALL OF THIS INTO CONSIDERATION...WILL NOT
GO ABOVE THE LOW-LIKELY POPS THAT WERE INHERITED. THERE WILL STILL
BE A SEVERE WEATHER THREAT...ESPECIALLY IF ANYTHING IS ABLE TO
ORGANIZE ALONG THE FRONT.

FRIDAY NIGHT AND SATURDAY...WITH THE UPPER LOW SPINNING NORTH OF THE
REGION...AND ANOTHER SHORT WAVE TROUGH DROPPING OUT OF THE PLAINS...
THE MID-LEVEL TROUGH AXIS/SURFACE FRONT TAKES ITS TIME PUSHING
THROUGH THE AREA. IN FACT...BOTH MODELS FEATURE QUITE A BIT OF QPF
ACROSS THE SOUTHEAST HALF OF THE FORECAST AREA AFTER 12Z SATURDAY.
THIS WILL NECESSITATE RAMPING POPS UP TO THE CHANCE RANGE IN THESE
AREAS. ALSO...BY SATURDAY AFTERNOON...THE SOUTHERN PORTION OF THE
FRONT IS SO DIFFUSE THAT THE NAM INITIATES HIGH TERRAIN CONVECTION.
THEREFORE...SLIGHT CHANCE POPS WILL EXIST AS FAR NORTH AND WEST AS
THE BLUE RIDGE.

&&

.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
AS OF 200 PM EDT WEDNESDAY...THE LATEST MEDIUM RANGE MODELS CONTINUE
TO INDICATE THAT THE TROUGH AXIS AND COLD FRONT WILL MOVE OFF TO THE
EAST LATE SATURDAY...WITH DECREASING PRECIPITATION FROM WEST TO
EAST. THEN DRY HIGH PRESSURE BUILDS IN FROM THE NW SUNDAY AND
REMAINS THROUGH MONDAY FOR RELATIVELY PLEASANT WEATHER. WILL
FORECAST DRY OVER THE PEDIMENT WITH SLIGHT CHANCE POPS ALONG THE
BLUE RIDGE SUN/MON. ANOTHER WEAK COLD FRONT IS EXPECTED TO PUSH
ACROSS THE AREA TUESDAY FOLLOWED BY HIGH PRESSURE ON WED. WITH LOWER
PW VALUES...PREDOMINANT DOWNSLOPE WEST WINDS AND WEAK
INSTABILITY...WILL MENTION SLIGHT TO LOW END CHANCE POPS FOR
DIURNAL CONVECTION TUE/WED. TEMPERATURES WILL BE A COUPLE DEGREES
BELOW SEASONAL AVERAGES DURING THE PERIOD.

&&

.AVIATION /22Z WEDNESDAY THROUGH MONDAY/...
AT KCLT...CONVECTION HAS DEVELOPED ALL AROUND THE AIRFIELD THIS AFTN
ON OUTFLOWS. TEMPO TSRA 19Z TO 23Z STILL LOOKS LIKE THE BEST WINDOW
FOR TSRA AT THE AIRFIELD. ANY GUSTS WOULD BE FROM THE N AND WILL BE
ADDED AS NECESSARY. MAINLY VFR CIGS ARE EXPECTED...BUT WITH TEMPO
MVFR UNDER TSRA. THE ACTIVITY SHOULD DIMINISH QUICKLY THIS EVENING.
A MOIST BOUNDARY LAYER UNDER DRYING MID AND UPPER LEVEL AIR COULD
LEAD TO ANOTHER ROUND OF LOW CLOUDS...HOWEVER...NONE OF THE GUIDANCE
FEATURES ANY RESTRICTIONS TOWARD DAYBREAK AT THIS POINT. WILL HINT
TOWARD IFR CONDITIONS WITH A FEW007 MENTION FOR NOW. WINDS WILL BE
LIGHT.

ELSEWHERE...TSTMS WERE FORMING ALL ALONG THE ERN ESCARPMENT OF THE
MTNS THIS AFTN...AND COVERAGE SHOULD SLOWLY EXPAND EASTWARD. TEMPO
TSRA CHANCES LOOK BEST FROM KGMU TO KGSP THIS AFTN...WITH VCTS
MENTION ELSEWHERE UNLESS SOMETHING GETS CLOSE. EXPECT MAINLY SCT TO
BKN VFR CUMULUS CLOUDS...WITH TEMPO CIGS EXPECTED UNDER TSTMS. FLOW
SHOULD REMAIN LIGHT SW TO WSW EAST OF THE MOUNTAINS AND NW AT KAVL.
THE ACTIVITY WILL DIMINISH QUICKLY THIS EVENING...WITH A DECENT
CHANCE OF LOW CLOUDS/FOG AGAIN OVERNIGHT GIVEN THE MOIST BL AND
DRYING ALOFT. THE BEST CHANCE OF DAYBREAK IFR WILL BE KAVL TO KHKY.

OUTLOOK...SCATTERED AFTERNOON TSTMS WILL DEVELOP AGAIN THU...MAINLY
IN THE MTNS. A COLD FRONT WILL APPROACH FROM THE NW ON FRIDAY TO
INCREASE THUNDERSTORM COVERAGE THROUGH FRI NIGHT. DRIER HIGH PRES
WILL RETURN OVER THE WEEKEND AND LINGER INTO EARLY 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...JOH
NEAR TERM...MCAVOY
SHORT TERM...JDL
LONG TERM...JOH
AVIATION...HG

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
327 PM EDT WED AUG 8 2012

GAZ010-017-018-026-028-029-NCZ033-035>037-048>053-056>059-062>065-
068>072-082-501>510-SCZ001>014-019-091930-
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-
327 PM EDT WED AUG 8 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 THUNDERSTORMS WILL CONTINUE TO DEVELOP OVER THE REGION
THIS AFTERNOON AND EVENING. THE STRONGEST STORMS WILL BE CAPABLE
OF PRODUCING A BRIEF PERIOD OF LOCALLY DAMAGING WIND GUSTS AND
PERHAPS LARGE HAIL. FREQUENT CLOUD TO GROUND LIGHTNING AND LOCALLY
HEAVY RAINFALL CAN OCCUR WITH ANY THUNDERSTORM.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY.

A STRONG COLD FRONT WILL APPROACH THE REGION LATE FRIDAY. THERE
IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ASSOCIATED WITH THE
FRONT. DAMAGING WIND GUSTS WILL BE THE PRIMARY THREAT.

.SPOTTER INFORMATION STATEMENT...

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

LANE

PRELIMINARY LOCAL STORM REPORT...CORRECTED
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
509 PM EDT WED AUG 08 2012

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0430 PM     TSTM WND DMG     7 WSW ANDERSON          34.48N 82.76W
08/08/2012                   ANDERSON           SC   LAW ENFORCEMENT

            HIGHWAY PATROL REPORTED A TREE BLOWN DOWN ON MOUNTAIN
            VIEW RD.

&&

LANE

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
519 PM EDT WED AUG 08 2012

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0440 PM     TSTM WND DMG     7 S MARION              35.58N 82.01W
08/08/2012                   MCDOWELL           NC   EMERGENCY MNGR

            EM REPORTS NUMEROUS TREES BLOWN DOWN IN THE GLENWOOD
            COMMUNITY.

&&

LANE

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
521 PM EDT WED AUG 08 2012

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0407 PM     TSTM WND DMG     3 S MARION              35.63N 82.02W
08/08/2012                   MCDOWELL           NC   TRAINED SPOTTER

            TREES DOWN BLOCKING THE EAST BOUND LANES OF INTERSTATE 40
            AND MORE TREES DOWN BLOCKING GOOSE CREEK ROAD WHICH IS
            JUST SOUTH OF THE INTERSTATE.

0407 PM     HAIL             3 S MARION              35.64N 82.01W
08/08/2012  E0.75 INCH       MCDOWELL           NC   TRAINED SPOTTER

            SPOTTER HAD DIME SIZED HAIL.

&&

OUTLAW

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
549 PM EDT WED AUG 08 2012

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0540 PM     TSTM WND DMG     6 SE GAFFNEY            35.01N 81.58W
08/08/2012                   CHEROKEE           SC   911 CALL CENTER

            COUNTY COMMS REPORTS NUMEROUS TREES BLOWN DOWN SOUTH OF
            GAFFNEY.

&&

LANE

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
556 PM EDT WED AUG 08 2012

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0430 PM     HAIL             6 S MARION              35.60N 82.01W
08/08/2012  E1.00 INCH       MCDOWELL           NC   PUBLIC

            PUBLIC REPORTED QUARTER SIZE HAIL IN THE GLENWOOD
            COMMUNITY.

&&

LANE

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
604 PM EDT WED AUG 8 2012

SCZ013-014-082230-
CHESTER-UNION-
604 PM EDT WED AUG 8 2012

...A STRONG THUNDERSTORM WILL AFFECT EASTERN UNION AND WESTERN
CHESTER COUNTIES THROUGH 630 PM EDT...

AT 602 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM 4 MILES SOUTHEAST OF LOCKHART...OR 12 MILES WEST
OF CHESTER...MOVING SOUTHEAST AT 5 MPH.

PEOPLE IN EASTERN UNION AND WESTERN CHESTER COUNTIES...INCLUDING THE
FOLLOWING LOCATION...

LOCKHART...

SHOULD MONITOR THE WEATHER SITUATION CLOSELY. LISTEN FOR POSSIBLE
WARNINGS AND BE PREPARED TO TAKE APPROPRIATE ACTION SHOULD SEVERE
WEATHER THREATEN.

PEA SIZE HAIL AND WIND GUSTS OF 40 TO 50 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 3479 8155 3483 8129 3464 8112 3458 8149

NED