Severe Thunderstorm Warning 23, NWS Greenville-Spartanburg, SC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
220 PM EDT SUN MAY 1 2016

.SYNOPSIS...
A COLD FRONT WILL APPROACH FROM THE WEST AN KEEP A WARM AND HUMID
AIR MASS ACROSS THE SOUTHEAST REGION THROUGH MONDAY. THIS FRONT WILL
SLOWLY PUSH EAST OF THE AREA ON TUESDAY. ANOTHER COLD FRONT WILL
CROSS THE AREA ON THURSDAY AND BRING COOLER CANADIAN AIR PERSISTING
INTO THE WEEKEND.

&&

.NEAR TERM /THROUGH MONDAY/...
COVERAGE OF CONVECTION WILL GRADUALLY INCREASE AS WILL INSTABILITY
THROUGH THE REMAINDER OF THE AFTERNOON. WILL CONTINUE TO ADVERTISE
LIKELY POPS ALONG THE ESCARPMENT BY EARLY EVENING. SBCAPE REMAINS
RATHER MUTED ACROSS THE FORECAST AREA THIS AFTERNOON...ESP ACROSS
THE NW NC PIEDMONT...WHERE LOW CLOUDS HAVE PERSISTED NORTH OF
INCREASINGLY DIFFUSE CAD BOUNDARY. NEVERTHELESS...ENOUGH SUN IS
PEEKING THROUGH THE CU AND STRATOCU THAT ONE COULD EXPECT THE
ATMOSPHERE TO FURTHER DESTABILIZE...WITH SBCAPE LIKELY REACHING 2000
J/KG ACROSS ROUGHLY THE SW HALF OF THE FORECAST AREA BY LATE
AFTERNOON. BULK SHEAR REMAINS MARGINALLY STRONG...THUS A COUPLE OF
ISOLATED SEVERE STORMS WILL REMAIN POSSIBLE...WITH LARGE HAIL AND
DAMAGING WINDS BEING THE PRIMARY THREATS.

THE SHORT TERM MODELS ARE GENERALLY IN GOOD AGREEMENT THAT A WEAK
MID-LEVEL SHORT WAVE TROUGH WILL APPROACH THE AREA FROM THE
SOUTHWEST THIS EVENING. THIS IS MOST LIKELY A RESULT OF GRID-SCALE
CONVECTIVE FEEDBACK...AS IT HAS ITS ORIGINS WITHIN AN AREA OF
CONVECTIVE PRECIP WITHIN THE MODEL(S) ENVIRONMENT. HOWEVER...
SOMETIMES SUCH THINGS ARE /REAL/. IT IS INTERESTING THAT SOME OF THE
LATEST MESOSCALE/CONVECTION-ALLOWING MODELS ARE LIKING THE IDEA OF
SOME VIGOROUS-LOOKING CONVECTION DEVELOPING OVER THE UPSTATE AND
NORTHEAST GA BY LATE EVENING. I/M NOT QUITE PREPARED TO JUMP ON THIS
YET...BUT SOLID CHANCE POPS WILL BE ADVERTISED ACROSS THE WESTERN
HALF OF THE AREA THROUGH THE EVENING HOURS...WITH POPS GRADUALLY
TAPERING DOWN OVERNIGHT.

LITTLE CHANGE IN THE WEATHER REGIME IS EXPECTED FOR MONDAY...AS DEEP
SW FLOW REMAINS IN PLACE...SUPPORTING ABOVE NORMAL TEMPS/LOW LEVEL
MOISTURE...AND DECENT AFTERNOON INSTABILITY...WHILE FORECAST
SOUNDINGS INDICATE PERSISTENT MODERATE LEVELS OF SHEAR. WITH THE
COLD FRONT EXPECTED TO REMAIN OFF TO OUR WEST THROUGH THE DAY
(ALBEIT JUST TO OUR WEST BY THE END OF THE DAY)...IT APPEARS THAT
TERRAIN EFFECTS WILL ONCE AGAIN BE THE PRIMARY IMPETUS FOR
INITIATION OF CONVECTION OVER OUR AREA. WILL ONCE AGAIN ADVERTISE
LIKELY POPS ALONG THE BLUE RIDGE BY MID-AFTERNOON...EXPANDING THOSE
TO THE REMAINDER OF THE MTNS BY THE END OF THE PERIOD...TO ACCOUNT
FOR ACTIVITY ORIGINATING FROM THE FRONT TO POSSIBLY MOVE INTO THE
FORECAST AREA. CHANCE POPS SHOULD SUFFICE ACROSS THE REMAINDER OF
THE AREA. ANOTHER DAY WITH A MARGINAL CONVECTIVE THREAT APPEARS
LIKELY.

&&

.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
AS OF 130 PM EDT SUNDAY...THE BROAD MODEL CONSENSUS DOES NOT LEAD TO
MUCH CHANGE TO THE GOING THINKING WITH RESPECT TO THE EXPECTED
SENSIBLE WEATHER FOR TUESDAY.  UPPER LEVEL HEIGHTS ATOP THE SE CONUS
WILL CONTINUE THEIR STEADY LOWERING AND A BROAD WSW FLOW THROUGH A
DEEP LAYER REMAINS. DESPITE THE LACK OF ANY LARGER SCALE FORCING...
SCATTERED DIURNAL ENHANCED TSTMS ARE STILL PROBABLE. THE UPPER
PATTERN CONTINUES TO AMPLIFY ON WEDNESDAY BUT THE LOWER LEVEL
BAROCLINIC ZONE IS PROGGED TO TRANSLATE DOWNSTREAM OF THE CWFA
LEAVING US IN A RELATIVE LULL. ENERGY DUMBBELLING AROUND DEEPENING
UPPER LOW MAY RESULT IN MTN SHOWERS BY WED NITE.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/...
AS OF 140 PM SUNDAY...GOOD CONFIDENCE IS HAD IN THE EXT RANGE FCST
AS THE OP MODELS ARE SHOWING GOOD AGREEMENT WITH THE ULVL PATTERN
AND THE SENSIBLE WX RESPONSE. THE GEFS MEMBERS ARE SHOWING LITTLE
SPREAD OVER THE ERN CONUS UNTIL LATE FRIDAY...MAINLY DUE TO DEEPNESS
DIFS WITH THE UPPER LOW.

THE PATTERN STILL SUGGESTS A DEVELOPING OMEGA BLOCK WITH THE ERN LOW
DEEPENING AND DROPPING SE OFF THE ATL COAST INTO THE SAT TIME
FRAME...THEN QUICKLY RISING HEIGHTS THROUGH THE REMAINDER OF THE
PERIOD. A COLD FRONT WILL BRING A SHOT OF LLVL MOISTURE TO THE FAR
WRN MTNS EARLY THU...WHICH WILL QUICKLY WANE AFTER SUNRISE. NOT
EXPECTING MUCH QPF RESPONSE FROM THIS FEATURE. THINGS WILL REMAIN
RATHER DRY AFTER THAT AS DEEP NW FLOW ENGULFS THE REGION AND A
REINFORCING SHOT OF LOW THETA/E AIR MIXES IN. THERE ARE SOME
DIFFERENCES FRI BTW THE OP MODELS WITH AN EMBEDDED S/W CREATING
SHOWERS ACROSS THE NRN ZONES...BUT GIVEN THE LARGE SCALE PATTERN AM
NOT ANTICIPATING MUCH MEASURABLE PRECIP WITH THIS SITUATION EITHER.
THE ATMOS WILL REMAIN RATHER STABLE THROUGH THE PERIOD...SO NO
THUNDER WILL BE INCLUDED IN THE GRIDS. OVERALL...THE PERIOD LOOKS TO
PRETTY NICE FOR EARLY MAY WITH MOSTLY DRY CONDS...MID/UPPER LEVEL
CLOUDS AND PLEASANT TEMPS. BELOW NORMAL HIGHS BY A CAT OR SO ARE
EXPECTED THU THRU SAT...THEN ABOVE NORMAL TEMPS PROBABLE BY SUN AS
UPPER RIDGE AXIS NEARS AND DEEP SUBS INCREASES.

&&

.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
AT KCLT AND ELSEWHERE...COVERAGE OF CONVECTION WAS GRADUALLY
INCREASING ACROSS THE WESTERN CAROLINAS AT 18Z...ESP ALONG AND NEAR
THE BLUE RIDGE. WITH INSTABILITY EXPECTED TO CONTINUE A GRADUAL
INCREASE...THIS TREND SHOULD CONTINUE SUCH THAT SCATTERED CONVECTION
SHOULD BE OCCURRING ACROSS MUCH OF THE TERMINAL FORECAST AREA BY
LATE AFTERNOON...CONTINUING INTO THE EVENING. MOST TERMINALS RECEIVE
A TEMPO FOR TSRA BTW 21 AND 01Z. ONE EXCEPTION IS AT KHKY...WHERE
INSTABILITY REMAINS WEAK UNDER OVERCAST MVFR CLOUDS. OTHERWISE...
PERIODIC MVFR CIGS WILL REMAIN POSSIBLE AT MOST TERMINALS THROUGH
THE AFTERNOON. WHILE A DOWNWARD TREND IN CONVECTION WILL BE
ADVERTISED BY LATE EVENING...THIS WILL NEED LATER REEVALUATION.
CONVECTION COULD POSSIBLY CONTINUE INTO THE OVERNIGHT HOURS...ESP
ACROSS UPSTATE SC AND FAR WESTERN NC...AS A WEAK UPPER AIR
DISTURBANCE APPPROACHES FROM THE SOUTHWEST.

WITH DRYING MID/UPPER LEVELS AND PLENTY OF LOW LEVEL MOISTURE
PERSISTING...CONDITIONS WILL BE FAVORABLE FOR DEVELOPMENT OF FOG
AND/OR STRATUS TOWARD DAYBREAK MONDAY. HOWEVER...THIS IS FAR FROM A
CERTAINTY...AND WE HAVE OPTED TO ONLY HINT AT THE POSSIBILITY WITH
3-6SM AND FEW/SCT CLOUDS IN THE IFR/MVFR RANGE. SCATTERED CONVECTION
MAY BEGIN TO REDEVELOP ACROSS THE MTNS BY THE END OF THE PERIOD.

OUTLOOK...UNSETTLED WEATHER/OCCASIONAL CONVECTION/RESTRICTIONS ARE
EXPECTED TO CONTINUE THROUGH ABOUT TUESDAY. DRYING IS EXPECTED BY
WEDNESDAY...AND THE DRY WEATHER SHOULD PERSIST THROUGH THE END OF
THE WEEK.

CONFIDENCE TABLE...

            18-24Z        00-06Z        06-12Z        12-18Z
KCLT       HIGH  84%     HIGH 100%     HIGH  90%     HIGH  86%
KGSP       HIGH  83%     HIGH 100%     HIGH 100%     HIGH  95%
KAVL       HIGH  97%     HIGH 100%     HIGH 100%     HIGH 100%
KHKY       HIGH  94%     HIGH 100%     HIGH  90%     HIGH 100%
KGMU       HIGH  81%     HIGH 100%     HIGH 100%     HIGH  97%
KAND       HIGH  90%     HIGH 100%     HIGH  98%     HIGH  94%

THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULE TAF ISSUANCE FLIGHT RULE CATEGORY.  COMPLET HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK:

WWW.WEATHER.GOV/GSP/AVIATION

&&

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

&&

SYNOPSIS...SBK
NEAR TERM...JDL
SHORT TERM...CSH
LONG TERM...SBK
AVIATION...JDL

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
429 AM EDT SUN MAY 1 2016

GAZ010-017-018-026-028-029-NCZ033-035>037-048>053-056>059-062>065-
068>072-082-501>510-SCZ001>014-019-020830-
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-
429 AM EDT SUN MAY 1 2016

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

.DAY ONE...TODAY AND TONIGHT.

THUNDERSTORMS WILL CONTINUE TO DEVELOP ACROSS THE REGION ON SUNDAY.
A FEW STRONG THUNDERSTORMS WILL BE POSSIBLE...PRODUCING SMALL HAIL
AND/OR GUSTY WIND...BUT THE BIGGEST THREAT WILL COME FROM
LOCALIZED VERY HEAVY RAINFALL.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY.

..MONDAY...THUNDERSTORMS ARE EXPECTED...SOME MAY BE ON THE STRONG
SIDE WITH AN ADDITIONAL RISK FROM LOCALIZED HEAVY RAINFALL.
..TUESDAY...NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.
..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.

.SPOTTER INFORMATION STATEMENT...

NONE.

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
1154 AM EDT SUN MAY 01 2016

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

0900 AM     FLASH FLOOD      1 ENE ROCK HILL         34.94N 81.01W
05/01/2016                   YORK               SC   SOCIAL MEDIA

            NEWSPAPER REPORTED VIA SOCIAL MEDIA THAT FLASH FLOODING
            DEVELOPED ALONG MANCHESTER CREEK AND AT LEAST ONE
            TRIBUTARY ON THE EAST SIDE OF ROCK HILL AGAIN THIS
            MORNING...AFTER AROUND 1.5 INCHES OF ADDITIONAL RAIN FELL
            IN A COUPLE OF HOURS. IMPACTED ROADS INCLUDED DAVE LYLE
            BLVD...RED RIVER RD...AND WILDWOOD DR.

&&

LANE

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
1240 PM EDT SUN MAY 01 2016

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

1237 PM     HEAVY RAIN       6 E ROCK HILL           34.93N 80.93W
05/01/2016  M8.07 INCH       YORK               SC   COCORAHS

            AN ESTIMATED 5 INCHES OF RAIN FELL BETWEEN 7 AND 930 PM.

&&

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
235 PM EDT SUN MAY 1 2016

NCZ065-507>510-011900-
RUTHERFORD MOUNTAINS NC-GREATER RUTHERFORD NC-HENDERSON NC-
EASTERN POLK NC-POLK MOUNTAINS NC-
235 PM EDT SUN MAY 1 2016

...A STRONG THUNDERSTORM WILL IMPACT PORTIONS OF NORTHWESTERN
RUTHERFORD...NORTHWESTERN POLK AND NORTHEASTERN HENDERSON COUNTIES
UNTIL 300 PM EDT...

AT 234 PM EDT...DOPPLER RADAR WAS TRACKING A STRONG THUNDERSTORM 10
MILES NORTHWEST OF COLUMBUS...OR 5 MILES SOUTH OF BAT CAVE...MOVING
EAST AT 25 MPH.

LOCATIONS TO BE IMPACTED INCLUDE...
LAKE LURE...BAT CAVE...CHIMNEY ROCK STATE PARK...LAKE ADGER...EDNEYVILLE...
SHINGLE HOLLOW...MILL SPRING...DANA AND GERTON.

DIME SIZE HAIL AND WIND GUSTS UP TO 40 MPH WILL BE POSSIBLE IN THESE
AREAS.

LAT...LON 3552 8207 3529 8207 3534 8239 3546 8237
      3548 8228 3546 8225 3549 8223
TIME...MOT...LOC 1834Z 269DEG 22KT 3538 8228

KRENTZ

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
243 PM EDT SUN MAY 1 2016

NCZ065-509-510-011915-
HENDERSON NC-EASTERN POLK NC-POLK MOUNTAINS NC-
243 PM EDT SUN MAY 1 2016

...A STRONG THUNDERSTORM WILL IMPACT PORTIONS OF WESTERN POLK AND
EAST CENTRAL HENDERSON COUNTIES UNTIL 315 PM EDT...

AT 243 PM EDT...DOPPLER RADAR WAS TRACKING A STRONG THUNDERSTORM 7
MILES EAST OF HENDERSONVILLE...OR 6 MILES NORTH OF SALUDA...MOVING
SOUTHEAST AT 15 MPH.

LOCATIONS TO BE IMPACTED INCLUDE...
LAKE ADGER AND DANA.

NIKCEL SIZE HAIL AND WIND GUSTS UP TO 40 MPH WILL BE POSSIBLE IN
THESE AREAS.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

DIME TO NICKEL SIZE HAIL CAN CAUSE CONSIDERABLE DAMAGE TO VEHICLES.
CONSIDER MOVING VEHICLES TO A COVERED STORAGE AREA BEFORE THE STORM
ARRIVES.

&&

LAT...LON 3532 8216 3520 8227 3520 8229 3534 8241
      3541 8230
TIME...MOT...LOC 1843Z 308DEG 11KT 3533 8232

LANE

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
347 PM EDT SUN MAY 1 2016

NCZ508-510-SCZ007-012015-
GREATER RUTHERFORD NC-EASTERN POLK NC-SPARTANBURG SC-
347 PM EDT SUN MAY 1 2016

...A STRONG THUNDERSTORM WILL IMPACT PORTIONS OF SOUTHEASTERN
RUTHERFORD...EASTERN POLK AND NORTH CENTRAL SPARTANBURG COUNTIES
UNTIL 415 PM EDT...

AT 346 PM EDT...DOPPLER RADAR WAS TRACKING A STRONG THUNDERSTORM 6
MILES EAST OF COLUMBUS...MOVING SOUTHEAST AT 15 MPH.

LOCATIONS TO BE IMPACTED INCLUDE...
LAKE BOWEN...BOILING SPRINGS SC...CHESNEE...LANDRUM...HENRIETTA...GREEN
CREEK...HARRIS...FINGERVILLE AND MILL SPRING.

NICKEL SIZE HAIL AND WIND GUSTS UP TO 40 MPH WILL BE POSSIBLE IN
THESE AREAS.

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 3526 8179 3518 8184 3518 8187 3516 8186
      3503 8195 3520 8222 3536 8212
TIME...MOT...LOC 1946Z 298DEG 13KT 3525 8210

TDP

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
401 PM EDT SUN MAY 1 2016

NCZ048-053-012030-
BUNCOMBE NC-MADISON NC-
401 PM EDT SUN MAY 1 2016

...A STRONG THUNDERSTORM WILL IMPACT PORTIONS OF SOUTHEASTERN MADISON
AND NORTHEASTERN BUNCOMBE COUNTIES UNTIL 430 PM EDT...

AT 401 PM EDT...DOPPLER RADAR WAS TRACKING A STRONG THUNDERSTORM 6
MILES EAST OF MARSHALL...OR NEAR MARS HILL...MOVING EAST AT 15 MPH.

LOCATIONS TO BE IMPACTED INCLUDE...
WEAVERVILLE...MARS HILL...B.R. PARKWAY-EAST ASHEVILLE TO CRAGGY
GARDENS...B.R. PARKWAY-CRAGGY TO LITTLE SWITZERLAND...MONTREAT AND
BARNARDSVILLE.

DIME SIZE HAIL AND WIND GUSTS UP TO 40 MPH WILL BE POSSIBLE IN THESE
AREAS.

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 3586 8242 3582 8241 3582 8236 3580 8234
      3578 8234 3575 8233 3573 8231 3573 8229
      3563 8230 3570 8266 3588 8264 3589 8245
TIME...MOT...LOC 2001Z 275DEG 15KT 3579 8256

TDP