Severe Thunderstorm Warning 227, NWS Greenville-Spartanburg, SC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
455 PM EDT TUE AUG 11 2015

.SYNOPSIS...
A COLD FRONT WILL BE CROSSING THE CAROLINA COAST EARLY WEDNESDAY
WHILE DRY HIGH PRESSURE BUILDS OVER OUR REGION.  EXPECT HIGH
PRESSURE TO BE IN CONTROL OF OUR WEATHER INTO EARLY NEXT WEEK. A FEW
MOUNTAIN SHOWERS AND STORMS MAY RETURN BY THE END OF THE WEEK.

&&

.NEAR TERM /THROUGH WEDNESDAY/...
AS OF 430 PM EDT...STRONG CONVECTION ACROSS THE UPSTATE AND PIEDMONT
OF NORTH CAROLINA...WITH BETWEEN 1500-2500 J/KG CAPE TO WORK WITH.
FAIRLY EFFICIENT RAINFALL PRODUCERS AS WELL. FOR THE MOST PART
STORMS ARE MOVING ENOUGH TO PRECLUDE MUCH IN THE WAY OF FLASH
FLOODING PROBLEMS BUT CELLS DEVELOPING ON OUTFLOWS COULD EXACERBATE
PROBLEMS...CASE IN POINT NEW FLASH FLOOD WARNING FOR THE CHARLOTTE
AREA. CONVECTION WILL CONTINUE TO PUSH EAST AND SHOULD BEGIN TO WANE
SHORTLY AS THE FRONT CONTINUES TO PUSH EAST. OVERALL GRIDS LOOK
PRETTY GOOD BUT MADE SOME MINOR CHANGES TO THE NEXT FEW HOURS TO
ACCOUNT FOR TRENDS.

AT 230 PM EDT...AN AMPLIFYING UPPER TROUGH AND AN APPROACHING COLD
FRONT...COMBINED WITH NOTABLE INSTABILITY...WILL SUPPORT CONVECTIVE
DEVELOPMENT THIS AFTERNOON. THE MODELS SHOW MORE SHEAR WITH THIS
ACTIVITY THAN THEY DID YESTERDAY...AND ORGANIZED STORMS CANNOT BE
COMPLETELY RULED OUT. THE BEST INSTABILITY WILL BE EAST OF THE BLUE
RIDGE. WITH MOIST VERTICAL PROFILES...HEAVY RAINFALL WILL BE
POSSIBLE...THOUGH STEERING FLOW SHOULD KEEP CELLS MOVING. LOW LEVEL
FLOW IS PARALLEL TO THE BLUE RIDGE...LIMITING UPSLOPE FLOW.

ACTIVITY SHOULD END THIS EVENING AS THE FRONT DEPARTS THE AREA.
COOLER...DRIER AIR WILL BE SLOW TO INFILTRATE OUR AREA...AND MINIMUM
TEMPERATURES WILL RUN NEAR NORMAL OVERNIGHT. NORTH WINDS SHOULD STAY
UP ENOUGH TO PREVENT DAYBREAK FOG FROM FORMING OVER MOST OF THE
AREA. WEDNESDAY FEATURES DRIER CONDITIONS...WITH HIGH TEMPERATURES
SLIGHTLY BELOW NORMAL.

&&

.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/...
AS OF 155 PM TUE...A PATTERN CHANGE IS IN STORE ACROSS THE REGION
THRU THE SHORT RANGE. A DEEP UPPER TROF OVER THE ERN SEABOARD BEGINS
TO MOVE EAST ON THU. HOWEVER...A WEAK SHORT WAVE AND RELATIVELY
STRONG UPPER JET MAX DIVE INTO THE TROF LATE THU INTO FRI. THIS
HELPS PINCH OFF THE SRN END OF THE TROF AND KEEP IT ACROSS THE SE.
THE NAM REACTION TO THIS DEVELOPMENT IS MUCH STRONGER THAN THE OTHER
GUIDANCE DEVELOPING A CLOSED LOW ALONG THE SE COAST...WHILE THE REST
OF THE GUIDANCE KEEPS IT AS AN OPEN WAVE. A WEAK LOW PRESSURE CENTER
FORMS ON THE STALLED SFC FRONT NEAR THE COAST. THIS COMBINED WITH
THE WEAK SFC HIGH MOVING INTO THE MID ATLANTIC STATES HELPS TURN THE
LOW LEVEL FLOW TO AN ELY OR SELY DIRECTION...ALLOWING A MOIST
UPSLOPE FLOW TO DEVELOP. THE RESULT IS LOW LEVEL MOISTURE RETURNING
ACROSS THE AREA ALONG WITH INSTABILITY ACROSS THE MTNS. THE NAM IS
MOST AGGRESSIVE WITH THIS PATTERN...AS IT WAS ON MONDAY. HOWEVER...
THE GFS IS NOW COMING AROUND TO THIS SCENARIO. THEREFORE...WILL NOT
GO AS STRONG AS THE NAM...BUT WILL TREND IN THAT DIRECTION. HAVE
GONE WITH ISOLATED DIURNAL CONVECTION ALONG AND NEAR THE BLUE RIDGE
ON THU...AND INCREASED THE AREA OF 20 POP TO INCLUDE THE FOOTHILLS
ON FRI...WITH AN AREA OF CHC POP ACROSS THE MTNS. HAVE INCREASED
CLOUD COVER IN RESPONSE AS WELL...BUT REMAINED BELOW MOSTLY CLOUDY
FOR NOW. HIGHS WILL BE A FEW DEGREES BELOW NORMAL...WITH LOWS NEAR
NORMAL.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
AS OF 150 PM TUE...THE 500MB PATTERN CONTINUES TO EVOLVE WITH THE
EAST COAST MAIN TROUGH LIFTING OUT TO THE NE WHILE THE SOUTHERN END
ELONGATES TOWARD THE GULF COAST.  CURRENT MODEL RUNS ARE LESS
CERTAIN THAT THERE WILL BE A CUT OFF UPPER LOW OVER THE NRN GULF.
THE 500MB RIDGE WILL CONTINUE OVER AZ AND SRN CALIFORNIA WHILE THE
MAIN FLOW BECOMES GENERALLY WEST TO EAST OVER THE NRN TIER OF THE
LOWER 48 AT 12Z MONDAY.  MODELS DIVERGE ON DAY 7 AS THE ECMWF
DEVELOPS A TROUGH OVER THE MID SECTION TUES NIGHT WHILE GFS
CONTINUES GENERAL WEST TO EAST FLOW OVER NRN TIER.

AT THE SURFACE...HIGH PRESSURE OVER THE APPALACHIANS WILL SHRINK IN
EXTENT OF INFLUENCE OVER THE WEEKEND AND INTO EARLY NEXT WEEK. A
STATIONARY FRONT FROM THE NRN GULF ACROSS NRN FL TO OFF THE CAROLINA
COAST WILL GRADUALLY DISSIPATE. THE NEXT COLD FRONT WILL CROSS THE
GREAT LAKES ON MONDAY AND REACHES THE OHIO RIVER EARLY TUESDAY.
LIGHT LOW LEVEL UPSLOPE FROM THE EAST AND SE COMBINED WITH
DIFFERENTIAL HEATING OF THE RIDGE TOPS AND VALLEYS IN THE MTNS WILL
CONTRIBUTE TO SOME DEVELOPING LATE DAY MTN CONVECTION EACH DAY.
TEMPS SLIGHTLY BELOW NORMAL SATURDAY THEN GETTING BACK TO AROUND
NORMAL INTO EARLY NEXT WEEK.

&&

.AVIATION /21Z TUESDAY THROUGH SUNDAY/...
AT KCLT...STRONG STORM MOVED THROUGH THE AREA WITH ITWS WINDS
GUSTING UP TO 39KT. ENOUGH CONVECTION STILL OUT THERE TO KEEP THE
TEMPO THROUGH 22Z BUT DROPPING THEREAFTER. OUTFLOW THAT WENT THROUGH
THE KCLT AREA BROUGHT WINDS AROUND TO THE N...BUT WINDS SHOULD SWING
BACK AROUND TO SW BRIEFLY BEFORE THE FRONT BRINGS WINDS NW AGAIN
/CURRENT TIMING 03Z/. GUIDANCE DOES NOT SUPPORT DAYBREAK FOG AS
WINDS AND GUSTS STAY UP OVERNIGHT. WEDNESDAY FEATURES N WINDS AND
DRY WEATHER.

ELSEWHERE...ROBUST CONVECTION AHEAD OF A COLD FRONT WILL AFFECT THE
MOUNTAINS FIRST...THEN THE FOOTHILLS...WITH ASSOCIATED RESTRICTIONS
AND WIND GUSTS. WINDS WILL VEER FROM SW TO NW AND THEN N BEHIND THE
FRONT THIS EVENING. ALTHOUGH SOME GUIDANCE SUPPORTS DAYBREAK FOG IN
THE MOUNTAINS...GUSTY N WINDS SHOULD PREVENT FOG FROM FORMING
ANYWHERE. DRIER WEATHER AND N WINDS PREVAIL ON WEDNESDAY.

OUTLOOK...INTRUDING HIGH PRESSURE WILL YIELD GENERALLY DRIER/VFR
CONDITIONS THRU WEEKS END...WITH THE POSSIBLE EXCEPTION OF EARLY
MORNING FOG/STRATUS AND AFTERNOON THUNDERSTORMS IN THE MOUNTAINS.

CONFIDENCE TABLE...

            21-03Z        03-09Z        09-15Z        15-18Z
KCLT       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KGSP       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KAVL       LOW   55%     LOW   55%     HIGH  81%     LOW   57%
KHKY       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KGMU       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KAND       HIGH 100%     HIGH 100%     HIGH  91%     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_TABLES

&&

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

&&

SYNOPSIS...DEO
NEAR TERM...JAT/TDP
SHORT TERM...RWH
LONG TERM...DEO
AVIATION...JAT/TDP

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
533 PM EDT TUE AUG 11 2015

GAZ010-017-018-026-028-029-NCZ033-035>037-048>053-056>059-062>065-
068>072-082-501>510-SCZ001>014-019-122145-
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-
533 PM EDT TUE AUG 11 2015

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

.DAY ONE...TONIGHT.

SCATTERED SHOWERS AND THUNDERSTORMS WILL CONTINUE INTO THE
EVENING. SOME OF THESE STORMS COULD PRODUCE GUSTY WINDS...HEAVY
RAINFALL...AND FREQUENT CLOUD TO GROUND LIGHTNING.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY.

..WEDNESDAY...NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.
..THURSDAY...NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.
..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.

.SPOTTER INFORMATION STATEMENT...

NONE.

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
525 PM EDT TUE AUG 11 2015

SCZ013-112200-
UNION SC-
525 PM EDT TUE AUG 11 2015

...STRONG THUNDERSTORM WILL IMPACT PORTIONS OF SOUTHEASTERN UNION
COUNTY UNTIL 600 PM EDT...

AT 525 PM EDT...DOPPLER RADAR WAS TRACKING A STRONG THUNDERSTORM 12
MILES SOUTH OF UNION...OR NEAR WHITMIRE...MOVING SOUTHEAST AT 20 MPH.

WIND GUSTS UP TO 40 MPH WILL BE POSSIBLE WITH THIS STORM.

LOCATIONS IMPACTED INCLUDE...
CARLISLE AND SANTUC.

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 3445 8155 3447 8155 3453 8162 3453 8164
      3455 8168 3458 8168 3466 8159 3461 8142
      3458 8143 3450 8142 3450 8144 3449 8144
      3449 8149 3445 8154
TIME...MOT...LOC 2125Z 297DEG 18KT 3455 8157

MOORE

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
602 PM EDT TUE AUG 11 2015

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

0530 PM     FLASH FLOOD      MONROE                  34.99N 80.54W
08/11/2015                   UNION              NC   COUNTY OFFICIAL

            MANY ROADWAYS FLOODED IN INDIAN TRAIL AND SOUTH TOWARD
            MONROE. THE NCDOT CLOSED OLD CHARLOTTE HWY DUE TO HIGH
            WATER LEVELS.

&&

KRENTZ

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