Severe Thunderstorm Warning 36, NWS Greenville-Spartanburg, SC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
257 PM EDT SUN MAY 10 2015

.SYNOPSIS...
THE REMNANTS OF ANA WILL TURN NORTHEAST AND MOVE ACROSS EASTERN
NORTH CAROLINA TONIGHT INTO MONDAY...BEFORE MOVING OFF THE VIRGINIA
COAST. A COLD FRONT WILL CROSS OUR AREA ON TUESDAY. HIGH PRESSURE
WILL TRANSIT FROM THE GREAT LAKES WEDNESDAY TO OFF THE MID ATLANTIC
COAST BY NEXT WEEKEND AS MOISTURE FLOWS UP FROM THE GULF AND INTO
OUR AREA.

&&

.NEAR TERM /THROUGH MONDAY/...
AS OF 230 PM...CONVECTION BEGINNING TO FIRE ACRS THE HIGH
TERRAIN...WHILE RAIN BANDS CONTINUE TO ROTATE AROUND T.D. ANA AS IT
LIFTS NORTH INTO INLAND ERN NC. THE I-77 CORRIDOR IS ON THE WESTERN
EDGE OF THE T.D. CLOUD SHIELD...WITH RADAR MOSAIC SHOWING INCREASING
SHWR COVERAGE TO THE EAST OF CHARLOTTE. SO THE POPS WILL FEATURE
HIGH-END CHC TO LIKELY IN THE CENTRAL AND SW NC MTNS...AND LOW-END
TO MID CHC EAST OF I-77...WITH SLGT CHC IN BETWEEN. CONVECTION MAY
BE ABLE TO SURVIVE OFF THE HIGH TERRAIN BETTER TODAY AS IT DRIFTS
SOUTH INTO THE UPPER SAVANNAH VALLEY AND WESTERN UPSTATE. STILL NOT
EXPECTING MUCH SEVERE THREAT...AS SHEAR IS VERY WEAK...AND INSTBY IS
AROUND 1000-1500 J/KG. AN ISOLD MARGINALLY SEVERE STORM CANNOT BE
RULED OUT.

TONIGHT...CONVECTION SHUD WANE...BUT A LINGERING SLGT CHC WILL
REMAIN...AS ATMOS REMAINS MOIST AND WEAKLY UNSTABLE ALOFT. LOWS WILL
BE ABOUT 10 DEG ABOVE NORMAL UNDER ELEVATED DWPTS AND SOME CLOUD
COVER.

MONDAY...THE 500 MB HEIGHTS WILL BEGIN TO FALL ATOP THE CWFA...AS A
LARGE TROF EJECTS OUT INTO THE PLAINS STATES. THE BL WILL BE QUITE
MOIST...WITH DEWPTS GENERALLY IN THE MID 60S ACRS THE
PIEDMONT...WHILE TEMPS SHUD WARM BACK INTO THE MID-UPR 80S. SO FCST
SNDGS SHOW STRONG SBCAPE...1500-2500 J/KG. SHEAR WILL REMAIN VERY
WEAK...AND DOWNBURST POTENTIAL LOOKS MUTED GIVEN WET-BULB ZERO
HEIGHTS OVER 10 KFT. SO EXPECT OVERALL BETTER TSTM COVERAGE ACRS THE
AREA (40-60 POP)...BUT SEVERE THREAT STILL LOOKS MARGINAL. WILL
PROBABLY SEE A FEW MARGINALLY SEVERE PULSE STORMS GIVEN THE GOOD
INSTBY. THERE WILL BE AN ISOLD FLASH FLOOD THREAT AS WELL...AS
STORMS WILL BE SLOW MOVING AND EFFICIENT RAIN PRODUCERS IN THE MOIST
ENVIRONMENT.

&&

.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
AS OF 150 PM SUNDAY...SHORT WAVE CROSSES THE AREA MONDAY NITE BEFORE
A DAMPENING UPPER TROF CROSSES ON TUE. AT THE SFC...THE ASSOCIATED
COLD FRONT CROSSES THE AREA ON TUESDAY. AHEAD OF THE FRONT...EXPECT
SOME LINGERING CONVECTION MONDAY NITE...THEN REDEVELOPING ON
TUE...MAINLY ALONG AND SOUTH OF I-85 WHERE BEST MOISTURE AND
INSTABILITY REMAIN. BULK SHEAR INCREASES SIGNIFICANTLY TUE AS WINDS
INCREASE WITH THE FRONT AND UPPER TROF. HOWEVER...INSTABILITY WILL
REMAIN WEAK AS INDICATED ON EVEN THE MOST ROBUST GUIDANCE.
THEREFORE...ONLY EXPECT THUNDER TO DEVELOP ALONG AND SOUTH OF I-85
WITH ONLY A VERY LOW SVR THREAT AT BEST. TEMPS REMAIN AROUND 10
DEGREES ABOVE NORMAL.

UPPER RIDGING BUILDS OVER THE CENTRAL CONUS WED WITH NWLY FLOW
DEVELOPING OVER THE AREA AS THE UPPER TROF MOVES EAST. AT THE SFC...
DRY AND COOLER HIGH PRESSURE BEGINS TO BUILD IN FROM THE NW. EXPECT
DRY CONDITIONS WITH TEMPS FROM NEAR NORMAL TO 5 DEGREES ABOVE.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
AS OF 255 PM SUNDAY...UPPER RIDGE BUILDS INTO THE AREA THU...THEN IS
KNOCKED DOWN FRI BY A SHORT WAVE MOVING OVER THE AREA. RIDGING
RETURNS FOR SAT AND SUN...ALTHOUGH A SHORT WAVE WILL MOVE THRU THE
RIDGE AND ACROSS THE AREA SUN.

DRY HIGH PRESSURE MOVES ACROSS THE AREA THU THEN OFF SHORE FRI. SLY
LOW LEVEL FLOW DEVELOPS FRI IN THE FLOW AROUND THE HIGH AND A LOW
PRESSURE MOVING ALONG A DEVELOPING WARM FRONT NEAR THE OH VALLEY.
THE MOIST SLY FLOW CONTINUES SAT. EXPECT INCREASING CHC OF SHOWERS
AND THUNDERSTORMS EACH DAY. THE MOIST AND UNSTABLE AIR MASS REMAINS
OVER THE AREA SUN WITH A CONTINUED CHC OF CONVECTION...BUT COULD
HAVE MORE OF A DIURNAL TREND. TEMPS START OUT NEAR NORMAL THU...
FALL A LITTLE BELOW NORMAL FRI...RETURN TO NEAR NORMAL SAT THEN BACK
ABOVE NORMAL SUN.

&&

.AVIATION /19Z SUNDAY THROUGH FRIDAY/...
AT KCLT...CLOUD BANDS CONTINUE TO SWIRL AROUND TROPICAL STORM
ANA...WITH BASES GRADUALLY LIFTING OVER KCLT. EXPECT BASES TO MIX
OUT TO ABOUT 4000 FT THIS AFTN AND GENERALLY REMAIN BKN. ENHANCED CU
WITHIN ONE OF THE CLOUD BANDS CAN BE SEEN FROM KGSO TO KEQY ON VIS
SAT...WITH A FEW LIGHT RADAR RETURNS BEGINNING TO DEVELOP. SO I
EXPECT AT LEAST A FEW WEAK SHRA PIVOTING FROM EAST TO WEST ACRS THE
KCLT THIS AFTN. NOT EXPECTING MUCH IMPACT...BUT CANNOT RULE OUT
BRIEF DOWNPOURS AND LOWER CIGS. WINDS WILL CONTINUE OUT OF THE NE
WITH GUSTS TILL ABOUT SUNSET...THEN WEAKEN. EXPECTING MORE
CLOUDINESS OVERNIGHT...AND GUIDANCE NOT SHOWING ANY LOWER STRATUS
THAN THE 4000 FT CIGS EXPECTED THIS AFTN. ON MONDAY...T.S. ANA WILL
DRIFT NE AWAY FROM THE AREA...BUT LEAVING PLENTY OF MOISTURE BEHIND.
SO EXPECTING A CU FIELD TO DEVELOP WITH BASES AROUND 5000 FT.
GUIDANCE SHOWS BETTER INSTBY FOR CONVECTION...WITH INTIATION LIKELY
STARTING IN THE MTNS. I THINK THE BEST CHCS AT KCLT WILL BE AFTER
18Z...SO NO MENTION WITH THIS TAF. WINDS WILL SHIFT TO SW BY LATE
MORNING...BUT REMAIN LIGHT.

ELSEWHERE...CONVECTION BEGINNING TO DEVELOP IN THE MTNS. GUIDANCE IN
DECENT AGREEMENT ON GOOD COVERAGE IN THE HIGH TERRAIN...WITH SOME
DEVELOPMENT OUT ACRS THE PIEDMONT...MAINLY AROUND KAND AND THE UPPER
SAVANNAH VALLEY. ALSO...RAIN BANDS MAY DEVELOP ON NORTH SIDE OF T.S.
ANA...AND PIVOT WESTWARD TOWARD KHKY. WILL MENTION VCTS AT KAVL AND
KAND WHERE THE COVERAGE WILL BE GREATEST. WINDS HAVE WEAKENED ACRS
THE UPSTATE AND BECOME RATHER VARIABLE. WINDS WILL BE TRICKY THRU
THE EVENING AS WELL. OVERNIGHT...CONVECTION SHUD WANE...WITH
LINGERING MID AND HIGH CLOUDS AROUND. MAY SEE SOME MTN VLY FOG...SO
WILL MENTION MVFR VSBY AT KAVL TO SHOW THE TREND. IF KAND GETS
RAINFALL...THERE MAY BE SOME MORNING FOG THERE AS WELL. ON
MONDAY...GUIDANCE IN GOOD AGREEMENT ON MORE INSTBY AND GREATER
COVERAGE OF CONVECTION. IT WILL MOST LIKELY GET STARTED IN THE MTNS
AROUND MIDDAY...SO WILL MENTION PROB30 AT KAVL. BUT THE PIEDMONT
SITES WILL SEE BEST CHCS AFTER 18Z...SO WILL LEAVE OUT MENTION.
WINDS WILL TURN OUT OF THE SW AND REMAIN LIGHT.

OUTLOOK...A COLD FRONT WILL CROSS THE AREA ON TUESDAY...BRINGING
ANOTHER ROUND OF DIURNAL SHRA AND TSRA. DRIER AIR MOVES IN ON
WEDNESDAY...BUT THE FRONT STALLS JUST TO THE SOUTH... POSSIBLY
ALLOWING UNSETTLED CONDITIONS TO RETURN TO THE AREA LATE IN THE WEEK.

CONFIDENCE TABLE...

            19-01Z        01-07Z        07-13Z        13-18Z
KCLT       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KGSP       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KAVL       HIGH 100%     HIGH 100%     HIGH  96%     HIGH  96%
KHKY       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KGMU       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KAND       HIGH 100%     HIGH 100%     HIGH  83%     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...RWH
NEAR TERM...ARK
SHORT TERM...RWH
LONG TERM...RWH
AVIATION...ARK

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
325 PM EDT SUN MAY 10 2015

GAZ010-017-018-026-028-029-NCZ033-048>053-058-059-062>065-501>510-
SCZ001>007-010>012-019-111930-
RABUN-HABERSHAM-STEPHENS-FRANKLIN-HART-ELBERT-AVERY-MADISON-YANCEY-
MITCHELL-SWAIN-HAYWOOD-BUNCOMBE-GRAHAM-NORTHERN JACKSON-MACON-
SOUTHERN JACKSON-TRANSYLVANIA-HENDERSON-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-ANDERSON-ABBEVILLE-LAURENS-GREENWOOD-
325 PM EDT SUN MAY 10 2015

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

.DAY ONE...TONIGHT.

SCATTERED THUNDERSTORMS WILL CONTINUE ACROSS THE NORTH CAROLINA
MOUNTAINS AND FOOTHILLS...NORTHEAST GEORGIA...AND THE WESTERN
UPSTATE INTO THE EVENING. WHILE THE MAIN THREATS WILL BE FROM
LOCALLY HEAVY RAINFALL AND CLOUD TO GROUND LIGHTNING...A COUPLE OF
STORMS COULD PRODUCE BRIEF SEVERE WEATHER IN THE FORM OF DAMAGING
WINDS AND LARGE HAIL.

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

..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.
..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.

NCZ035>037-056-057-068>072-082-SCZ008-009-013-014-111930-
ALEXANDER-IREDELL-DAVIE-CATAWBA-ROWAN-CLEVELAND-LINCOLN-GASTON-
MECKLENBURG-CABARRUS-UNION-CHEROKEE-YORK-CHESTER-
325 PM EDT SUN MAY 10 2015

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

.DAY ONE...TONIGHT.

SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WILL CONTINUE ACROSS
THE NORTH CAROLINA PIEDMONT AND EASTERN UPSTATE INTO THE EVENING.
THE MAIN THREATS WILL BE FROM LOCALLY HEAVY RAINFALL AND CLOUD TO
GROUND LIGHTNING.

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

..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.
..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.

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
259 PM EDT SUN MAY 10 2015

GAZ010-SCZ001-101930-
RABUN GA-OCONEE MOUNTAINS SC-
259 PM EDT SUN MAY 10 2015

...A STRONG THUNDERSTORM WILL IMPACT PORTIONS OF NORTHEASTERN RABUN
AND NORTH CENTRAL OCONEE COUNTIES UNTIL 330 PM EDT...

AT 259 PM EDT...DOPPLER RADAR WAS TRACKING A STRONG THUNDERSTORM 14
MILES NORTHWEST OF WALHALLA...OR 6 MILES NORTHWEST OF OCONEE STATE
PARK...MOVING SOUTH AT 5 MPH.

HALF INCH HAIL AND WIND GUSTS UP TO 40 MPH WILL BE POSSIBLE WITH THIS
STORM.

LOCATIONS IMPACTED INCLUDE...
OCONEE STATE PARK...PINE MOUNTAIN AND MOUNTAIN REST.

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.

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.

&&

LAT...LON 3500 8322 3500 8311 3486 8305 3485 8323
TIME...MOT...LOC 1859Z 353DEG 6KT 3496 8317

08

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
328 PM EDT SUN MAY 10 2015

GAZ010-SCZ001-102000-
RABUN GA-OCONEE MOUNTAINS SC-
328 PM EDT SUN MAY 10 2015

...A STRONG THUNDERSTORM WILL IMPACT PORTIONS OF CENTRAL RABUN AND
NORTHWESTERN OCONEE COUNTIES UNTIL 400 PM EDT...

AT 327 PM EDT...DOPPLER RADAR WAS TRACKING A STRONG THUNDERSTORM 8
MILES NORTHEAST OF CLAYTON...OR 5 MILES SOUTHEAST OF SKY VALLEY...
MOVING SOUTHWEST AT 10 MPH.

NICKEL SIZE HAIL...WIND GUSTS UP TO 50 MPH...AND VERY HEAVY RAINFALL
RATES UP TO 2 INCHES PER HOUR WILL BE POSSIBLE WITH THIS STORM.

LOCATIONS IMPACTED INCLUDE...
CLAYTON...MOUNTAIN CITY...TIGER...SKY VALLEY...BLACK ROCK MOUNTAIN
STATE PARK...DILLARD...LAKEMONT...TALLULAH GORGE STATE PARK...PINE
MOUNTAIN AND LONG CREEK.

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 3500 8334 3500 8323 3492 8312 3469 8328
      3487 8353
TIME...MOT...LOC 1927Z 041DEG 11KT 3493 8326

HG