Severe Thunderstorm Warning 255, NWS Greenville-Spartanburg, SC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
237 PM EDT THU SEP 10 2015

.SYNOPSIS...
A COLD FRONT AND UPPER TROUGH WILL SLOWLY SWEEP OVER THE SOUTHERN
APPALACHIAN REGION LATE THIS WEEK. BY EARLY NEXT WEEK...A COOL AND
DRY AIR MASS IS FORECAST TO SETTLE OVER THE WESTERN CAROLINAS AND
NORTHEAST GEORGIA. MOISTURE SHOULD BEGIN TO INCREASE OVER THE REGION
BY THE MIDDLE OF NEXT WEEK.

&&

.NEAR TERM /THROUGH FRIDAY/...
AS OF 225 PM...THE AXIS OF AN UPPER TROF CONTINUES TO PUSH
EAST...ENTERING THE NC MTNS ATTM. MEANWHILE...A COLD FRONT WAS
ANALYZED WINDING FROM THE MID ATLANTIC TO THE TN VALLEY...TO THE
SOUTHERN PLAINS. THE AIR MASS ALONG AND SOUTH OF THE BNDRY IS QUITE
MOIST...WITH DEWPTS IN THE UPR 60S TO LWR 70S. THIS HAS RESULTED IN
SBCAPE IN THE 1000 TO 2000 J/KG RANGE...EVEN HIGHER JUST SOUTH AND
EAST OF THE CWFA. SO EXPECT CONVECTION TO CONTINUE TO INCREASE IN
COVERAGE AND INTENSITY ACRS THE AREA THRU THE AFTN.

CONVECTION SHUD DIMINISH THIS EVENING AS ATMOS STABILIZES AND UPPER
ENERGY EXITS TO THE EAST. THE COLD FRONT WILL STALL IN THE MTNS FOR
MUCH OF THE NIGHT...WHILE NWLY LLVL FLOW HELPS SCOUR OUT CLOUD
COVER. SO PATCHY FOG AND STRATUS IS EXPECTED TO DEVELOP ACRS THE
AREA...ESP WHERE THE HEAVIEST RAIN FALLS AND IN THE MTN VALLEYS.
TEMPS WILL DROP A CATEGORY OR TWO COOLER THAN THIS MORNING/S LOWS
FOR FRIDAY MORNING.

FRIDAY...THE CWFA WILL BE IN BETWEEN SHORTWAVE TROFS AND BETWEEN SFC
FRONTS. LLVL FLOW WILL REMAIN WLY TO NWLY...LIMITING MOISTURE AND
LLVL CONVERGENCE. SO EXPECT ONLY ISOLATED TO WIDELY SCATTERED
CONVECTION WITH PEAK HEATING FRIDAY AFTN. TEMPS WILL BE A CATEGORY
OR TWO ABOVE NORMAL.

&&

.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
AS OF 215 PM THURSDAY...LINGERING SCATTERED/ISOLATED DIURNAL
CONVECTION IS EXPECTED TO WANE FRI EVENING...BUT POPS WILL INCREASE
AGAIN TOWARD DAYBREAK ACROSS THE MTNS...AS A BAND OF DEEP MOISTURE
ASSOCIATED WITH STRONG HEIGHT FALLS AND ASSOCIATED FRONTAL SURGE
APPROACHES THE FORECAST AREA. WHILE THE MOIST BAND IS EXPECTED TO
DIMINISH AS IT MOVES QUICKLY ACROSS THE FORECAST AREA DURING THE
MORNING...MID-LEVEL DRY SLOT WILL OVERSPREAD THE AREA DURING THE
AFTERNOON...WITH PART OF THE FRONT LIKELY GETTING HUNG UP A BIT
ACROSS THE MOUNTAINS...LIKELY NOT COMPLETELY CLEARING THE AREA UNTIL
A POTENT SHORT WAVE TROUGH MOVES ACROSS THE AREA DURING THE EVENING.
AS A RESULT...THERE SHOULD BE PLENTY OF LOW LEVEL MOISTURE AND
WARMTH LINGERING THROUGH THE DAY TO SUPPORT MODEST LEVELS OF
INSTABILITY. TERRAIN EFFECTS AND THE FRONT SHOULD PROVIDE FOCI FOR
SCATTERED CONVECTIVE DEVELOPMENT INTO THE AFTERNOON AND EARLY
EVENING...ESP FROM THE BLUE RIDGE EAST...PRIMARILY WARRANTING CHANCE
POPS.

WITH CANADIAN HIGH PRESSURE BUILDING INTO THE REGION IN THE WAKE OF
DEPARTING TROUGH/COLD FRONT...SUNDAY SHAPES UP TO BE A SPECTACULAR
EARLY TASTE OF AUTUMN...WITH MAXES EXPECTED IN THE 70S AND DEWPOINTS
LIKELY FALLING INTO THE 40S BY AFTERNOON.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AS OF 225 PM THURSDAY...THE EARLY PART OF THE MEDIUM RANGE WILL BE
DOMINATED BY AN ANOMALOUSLY DEEP...YET PROGRESSIVE EAST COAST LONG
WAVE TROUGH AND ASSOCIATED CANADIAN HIGH PRESSURE. THIS WILL SUPPORT
A CONTINUATION OF EARLY FALL-LIKE WEATHER...WITH TEMPS/DEWPOINTS
EXPECTED TO REMAIN BELOW CLIMO THROUGH AT LEAST TUESDAY. IN FACT...
MON MORNING IS EXPECTED TO BE DOWNRIGHT CHILLY ACROSS THE HIGH
ELEVATIONS...WITH TEMPS LIKELY DIPPING TO NEAR 40 ABOVE 4000 FEET OR
SO. HEIGHT RISES BY THE END OF THE PERIOD WILL RESULT IN TEMPS
CREEPING BACK TOWARD CLIMO...ALTHOUGH WITH SURFACE RIDGE AXIS
EXPECTED TO PERSIST ACROSS THE REGION...DEWPOINTS SHOULD BE SLOWER
TO RECOVER...AND IT APPEARS CHANCES FOR ANY DIURNAL CONVECTION...OR
PRECIP OF ANY STRIPE WILL BE BELOW 20 PERCENT THROUGH THE PERIOD.

&&

.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
AT KCLT...A COLD FRONT WILL CROSS THE AREA TONIGHT FROM THE NW.
SCATTERED TO NUMEROUS SHRA AND TSRA WILL DEVELOP ALONG AND AHEAD OF
THE FRONT THIS AFTN. THERE WILL ALSO BE SOME LOW-END GUSTS OUT OF
THE SW...WHICH MAY BECOME VARIABLE IF ANY TSTMS ARE NEARBY. WILL
CONTINUE TO HIGHLIGHT THIS IN A TEMPO GROUP FROM 21-24Z.
OVERNIGHT...EXPECT WINDS TO DIMINISH...WITH SOME CLEARING OF SKIES.
SO THERE MAY BE SOME PATCHY STRATUS AND/OR FOG AROUND DAYBREAK. WITH
THE EXPECTED DECENT COVERAGE OF PRECIP EXPECTED...I WILL ADD AN IFR
CIG FOR THE DAYBREAK PERIOD FRIDAY MORNING. IF PRECIP IS NOT AS
EXTENSIVE...THIS MAY BE DIALED BACK WITH SUBSEQUENT UPDATES. WINDS
WILL SWITCH TO NW WITH THE FROPA AROUND 12Z...BUT SHUD REMAIN LIGHT.

ELSEWHERE...SO FAR SCATTERED CONVECTION HAS DEVELOPED ACRS PORTIONS
OF NC AND UPSTREAM ACRS TN. EXPECT COVERAGE TO INCREASE THRU THE
REST OF THE AFTN INTO EARLY EVENING. HAVE VCTS AND TEMPO GROUPS AT
ALL SITES TO HIGHLIGHT THIS. WINDS WILL BE MARGINALLY GUSTY ACRS THE
UPSTATE OUT OF THE SW. WINDS WILL SHIFT OUT OF THE NW AT KAVL BY
EARLY EVENING...AND AT THE REST OF THE SITES OVERNIGHT...AS A COLD
FRONT PASSES THRU. WINDS WILL BE LIGHT AND SKIES WILL SEE SOME
GRADUAL CLEARING. SO PATCHY FOG AND/OR STRATUS IS POSSIBLE...ESP
WHERE RAIN FALLS AND IN THE MTN VALLEYS.

OUTLOOK...UNSETTLED CONDITIONS WILL CONTINUE THROUGH THE WEEKEND AS
A FRONT STALLS IN THE REGION...AND AN UPPER LEVEL LOW PRESSURE
SYSTEM DRIFTS EAST THROUGH THE APPALACHIANS. MTN VALLEY FOG AND
STRATUS ARE POSSIBLE EACH MORNING...WITH SCATTERED THUNDERSTORMS
MAINLY IN THE AFTN. DRIER CONDITIONS WILL ARRIVE EARLY NEXT WEEK.

CONFIDENCE TABLE...

            18-24Z        00-06Z        06-12Z        12-18Z
KCLT       HIGH 100%     HIGH 100%     HIGH  84%     HIGH  94%
KGSP       HIGH 100%     HIGH 100%     HIGH  97%     HIGH 100%
KAVL       HIGH  93%     HIGH  95%     HIGH  83%     HIGH  88%
KHKY       HIGH 100%     HIGH 100%     HIGH  97%     HIGH 100%
KGMU       HIGH 100%     HIGH 100%     HIGH  97%     HIGH 100%
KAND       HIGH 100%     HIGH 100%     HIGH  94%     HIGH 100%

THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)

WWW.WEATHER.GOV/GSP/AVIATION

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.

&&

SYNOPSIS...RWH
NEAR TERM...ARK
SHORT TERM...JDL
LONG TERM...JDL
AVIATION...ARK

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
455 AM EDT THU SEP 10 2015

GAZ010-017-018-026-028-029-NCZ033-035>037-048>053-056>059-062>065-
068>072-082-501>510-SCZ001>014-019-110900-
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-
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-CHESTER-GREENWOOD-
455 AM EDT THU SEP 10 2015

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

.DAY ONE...TODAY AND TONIGHT.

SHOWERS AND THUNDERSTORMS WILL DEVELOP ACROSS THE AREA AGAIN TODAY
AND CONTINUE INTO THE EVENING. AREAS OF HEAVY RAINFALL ARE
POSSIBLE...ALONG WITH CLOUD TO GROUND LIGHTNING.

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

..FRIDAY...NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.
..SATURDAY...NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.
..SUNDAY...NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.
..MONDAY...NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.
..TUESDAY...NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.
..WEDNESDAY...NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

NONE.

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
144 PM EDT THU SEP 10 2015

NCZ037-101815-
DAVIE NC-
144 PM EDT THU SEP 10 2015

...STRONG THUNDERSTORM WILL IMPACT PORTIONS OF NORTHERN DAVIE COUNTY
UNTIL 215 PM EDT...

AT 143 PM EDT...DOPPLER RADAR WAS TRACKING A STRONG THUNDERSTORM 8
MILES NORTH OF MOCKSVILLE...OR 5 MILES SOUTHEAST OF COURTNEY...MOVING
EAST AT 15 MPH.

PEA SIZE HAIL AND WIND GUSTS UP TO 40 MPH WILL BE POSSIBLE WITH THIS
STORM.

LOCATIONS IMPACTED INCLUDE...
MOCKSVILLE...BERMUDA RUN...SHEFFIELD...ADVANCE AND FARMINGTON.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TORRENTIAL RAINFALL 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.

THIS STORM MAY INTENSIFY...SO BE CERTAIN TO MONITOR LOCAL RADIO AND
TV STATIONS...AS WELL AS LOCAL CABLE TV OUTLETS...FOR ADDITIONAL
INFORMATION AND POSSIBLE WARNINGS FROM THE NATIONAL WEATHER SERVICE.

&&

LAT...LON 3591 8037 3590 8069 3605 8068 3605 8050
      3606 8047 3606 8046 3603 8044 3599 8042
      3596 8038 3593 8037
TIME...MOT...LOC 1743Z 259DEG 13KT 3601 8056

NED

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
321 PM EDT THU SEP 10 2015

NCZ506-508-101945-
GREATER RUTHERFORD NC-EASTERN MCDOWELL NC-
321 PM EDT THU SEP 10 2015

...STRONG THUNDERSTORM WILL IMPACT PORTIONS OF NORTHEASTERN
RUTHERFORD AND SOUTHEASTERN MCDOWELL COUNTIES UNTIL 345 PM EDT...

AT 320 PM EDT...DOPPLER RADAR WAS TRACKING A STRONG THUNDERSTORM 10
MILES NORTH OF RUTHERFORDTON...MOVING EAST AT 25 MPH.

ANOTHER STRONG THUNDERSTORM WAS DEVELOPING ABOUT 2 MILES NORTH OF
RUTHERFORDTON...ALSO MOVING EAST AT 25 MPH.

PEA SIZE HAIL AND WIND GUSTS UP TO 40 MPH WILL BE POSSIBLE WITH
THESE STORMS.

LOCATIONS IMPACTED INCLUDE...
FOREST CITY...RUTHERFORDTON...SPINDALE...ELLENBORO...BOSTIC...UNION
MILLS...THERMAL CITY...SUNSHINE...GREEN HILL AND FERO.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THIS STORM MAY INTENSIFY...SO BE CERTAIN TO MONITOR LOCAL RADIO AND
TV STATIONS...AS WELL AS LOCAL CABLE TV OUTLETS...FOR ADDITIONAL
INFORMATION AND POSSIBLE WARNINGS FROM THE NATIONAL WEATHER SERVICE.

&&

LAT...LON 3535 8171 3528 8174 3534 8197 3541 8206
      3558 8205 3558 8170
TIME...MOT...LOC 1920Z 269DEG 22KT 3551 8199

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