Special Weather Statement, NWS Greenville-Spartanburg, SC

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
445 PM EDT WED JUN 29 2016

.SYNOPSIS...
Weak high pressure currently in place over the Mid West will drift
slowly eastward toward the area by the end of the week. A slow
moving cold front will stall out south of the area before slowly
pushing northward and moving north of the area by the beginning of
next week.

&&

.NEAR TERM /THROUGH THURSDAY/...
As of 435 PM...Water vapor imagery shows a potent short wave
dropping quickly through Missouri, which will pass north of our
area during the evening. Convergence invof old front (or trough)
is also a factor for showers and thunderstorms this afternoon and
evening. SBCAPE remains close to 1000 J/kg, with DCAPE nearing
1k. Shear appears to be too weak to permit much organization to the
storms, but strong enough to allow them to persist much longer than
a pulse updraft. Activity is expected to progress southeastward
from its current location from Columbus to Mocksville. Outflow
boundaries are noted, but CAPE is smaller along/south of I-85 and
any new development along them should remain isolated.

Considering the orientation of the jet, surface features and
higher precipitable water values back to our southwest, we believe
isolated showers or t-storms will linger through the evening,
and perhaps past midnight.

The setup Thursday for storms appears even more favorable. The
deep New England upper level trough will drop a bit farther south
Thursday. Wind fields will respond with 0-6km bulk shear about
30 knots and CAPES very impressive from both the NAM and GFS. We
will probably be watching areas near any local frontal convergence,
differential heating and lobes of stronger winds aloft. Storms on
Thursday may develop into loose clusters during the afternoon. We
have followed consensus on the POPS Thursday with mid range values
until we can get a good handle on location and focus. Much of our
area Thursday is in the Marginal Risk for severe storms.

Temperatures tonight and Thursday are a blend of several sets of
guide, but look considerably close to MOS values. Finally would
expect some patchy fog in the valley prone areas, and those places
which have rain. However, if cloudiness thins tonight, then more
fog would be expected.

&&

.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...
As of 215 PM EDT Wednesday: General troughiness will be in place
through the short term, with a shortwave spinning across southern
Canada and another pushing across the Gulf Coast. The weak cold
front that will be hanging around the area through the near-term
will slide just to our southeast as we push into the short-term,
with weak high pressure developing in the lee of the Appalachians.
Dewpoints should drop several degrees during the afternoon on Friday
with northwest surface flow in place across the mountains leading to
a bit of drying downslope winds, and thus should see a bit of a lull
in convection as a result, with a minimum of CAPE across the area.
However, as the NAM does still want to paint between 500-1000 J/kg
sbCAPE, have kept slight chance pops in through the afternoon.

The Canadian wave rotates slightly northeastward Friday night as the
Gulf Coast wave damps, leaving sort of an isolated vort max and
associated moisture field. The frontal boundary will slide slowly
back to the north and begin merging with an area of moisture
associated with a shortwave coming off the Central Rockies. Should
see a return to diurnal convection Saturday afternoon. Temperatures
will hover a degree or two above seasonal normals.

&&

.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
As of 230 PM EDT Wednesday: The aforementioned upper trough and
Canadian shortwave continue to lift out of the area through the
weekend, leaving mainly zonal flow across the area, but with this
elongated front stretching from the Plains to the Carolina coast
meandering around the area. The former Gulf Coast shortwave will
also continue to slide northeast toward the area as the Rockies wave
moves east and deepens over the mid-Mississippi Valley. All this
additional moisture should leave to slightly higher than climo pops
across the area for Sunday and Monday afternoons, with likely pops
across the mountains and northern tier (or wherever the front ends
up) and chances elsewhere. Probably not what area residents want to
hear for Independence Day festivities, but we'll continue to refine
the forecast as we move forward.

Uncertainty really increases into the beginning of the work week as
the operational models differ on how to handle that mid-Mississippi
shortwave as it traverses east. ECMWF wants to keep the flow more
zonal with a weaker wave/surface reflection while the GFS has more
of a bonafide trough and surface low/front pushing through by
Tuesday night. Both generally keep the more active weather to our
north across the Ohio Valley. ECMWF is also faster with the
subtropical ridge moving back in to dominate the area toward the
middle of next week. Have trended slightly warmer with afternoon
highs, inching toward the mid-90s by the end of the period, with
lows also remaining above climo, and near-climo pops.

&&

.AVIATION /21Z WEDNESDAY THROUGH MONDAY/...
At KCLT and elsewhere: Deep convection ongoing over WNC but
currently between TAF sites. Outflow boundaries are expected to move
S from these cells and impact KCLT and perhaps KGSP no later than
22z. Scattered showers may redevelop as these boundaries encounter
unstable air over the Upstate, but current mention of TS in TEMPO
looks good. Some activity could linger into the evening as well
due to dynamic lift coming from a jet streak aloft. Later in the
evening some patchy fog has also been introduced. We will continue
to monitor for timing issues. Bottom line, VFR with restrictions
to ceilings and visibilities in showers and thunderstorms. Also
a few hours of MVFR fog late tonight. We have added some IFR fog
restrictions to AVL late tonight, thinking they have a better
chance to break out of any cloudiness.

Outlook: Warm and moist conditions with daily thunderstorm chances
will be on tap Friday and Saturday. Another frontal system may
make a run toward our region Sunday and Monday, which could enhance
thunderstorm activity.

Confidence Table...

            20-02Z        02-08Z        08-14Z        14-18Z
KCLT       High 100%     High 100%     High  83%     High  89%
KGSP       High 100%     High 100%     High  87%     High 100%
KAVL       High 100%     High 100%     High  87%     High  97%
KHKY       High 100%     High 100%     Med   65%     High  87%
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 schedule TAF issuance flight rule category. Complete 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...Staarmann
NEAR TERM...TS/Wimberley
SHORT TERM...TDP
LONG TERM...TDP
AVIATION...TS/Wimberley

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
346 PM EDT WED JUN 29 2016

GAZ010-017-018-026-028-029-NCZ033-035>037-048>053-056>059-062>065-
068>072-082-501>510-SCZ001>014-019-302000-
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-
346 PM EDT WED JUN 29 2016

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 ARE EXPECTED ACROSS THE AREA THROUGH THIS
EVENING. ISOLATED LARGE HAIL OR DAMAGING WINDS WILL BE POSSIBLE
ESPECIALLY ACROSS THE FOOTHILLS AND PIEDMONT OF NORTH CAROLINA.
HOWEVER...THE MAIN THREATS WILL BE CLOUD TO GROUND LIGHTNING...
GUSTY WINDS...SMALL HAIL...AND BRIEF HEAVY RAINFALL.

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

..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.
..TUESDAY...NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

NONE.

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
539 PM EDT WED JUN 29 2016

SCZ008-292215-
CHEROKEE SC-
539 PM EDT WED JUN 29 2016

...A THUNDERSTORM WITH TORRENTIAL RAINFALL WILL IMPACT CENTRAL
CHEROKEE COUNTY UNTIL 615 PM EDT...

AT 539 PM EDT...DOPPLER RADAR WAS TRACKING A THUNDERSTORM WITH
TORRENTIAL RAINFALL NEAR GAFFNEY...MOVING SOUTHEAST AT 20 MPH.

LOCATIONS TO BE IMPACTED INCLUDE...
GAFFNEY...DRAYTONVILLE AND CHEROKEE FALLS.

WIND GUSTS UP TO 40 MPH AND TORRENTIAL RAINFALL RATES UP TO 3 INCHES
PER HOUR WILL BE POSSIBLE IN THESE AREAS.

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 MAY ALSO RISE RAPIDLY. SEEK
HIGHER GROUND IF THREATENED BY FLOOD WATERS. DO NOT DRIVE ACROSS
FLOODED ROADS.

&&

LAT...LON 3505 8172 3511 8169 3509 8147 3494 8155
TIME...MOT...LOC 2139Z 294DEG 18KT 3506 8164

LANE

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
607 PM EDT WED JUN 29 2016

NCZ064-SCZ001-002-292230-
TRANSYLVANIA NC-PICKENS MOUNTAINS SC-OCONEE MOUNTAINS SC-
607 PM EDT WED JUN 29 2016

...A STRONG THUNDERSTORM WILL IMPACT SOUTHWESTERN TRANSYLVANIA...
NORTH CENTRAL OCONEE AND NORTHWESTERN PICKENS COUNTIES UNTIL 630 PM
EDT...

AT 606 PM EDT...DOPPLER RADAR WAS TRACKING A STRONG THUNDERSTORM 19
MILES NORTH OF WALHALLA...OR NEAR GORGES STATE PARK...MOVING EAST AT
10 MPH.

LOCATIONS TO BE IMPACTED INCLUDE...
GORGES STATE PARK...LAKE JOCASSEE...JOCASSEE GORGES AND BAD CREEK.

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

PRECAUTIONARY/PREPAREDNESS ACTIONS...

LAKE JOCASSEE IS IN THE PATH OF THIS STORM. CLOUD TO GROUND
LIGHTNING AND GUSTY WINDS WILL CREATE DANGEROUS BOATING CONDITIONS.
MOVE TO SHORE IMMEDIATELY.

&&

LAT...LON 3509 8303 3511 8287 3496 8289 3502 8304
      3503 8302 3503 8301 3504 8303 3505 8304
      3508 8304
TIME...MOT...LOC 2206Z 279DEG 10KT 3505 8300

LANE

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
631 PM EDT WED JUN 29 2016

NCZ502-292300-
GREATER CALDWELL NC-
631 PM EDT WED JUN 29 2016

...A STRONG THUNDERSTORM WILL IMPACT CENTRAL CALDWELL COUNTY UNTIL
700 PM EDT...

AT 630 PM EDT...DOPPLER RADAR WAS TRACKING A STRONG THUNDERSTORM NEAR
LENOIR...MOVING NORTHEAST AT 15 MPH.

LOCATIONS TO BE IMPACTED INCLUDE...
LENOIR...CEDAR ROCK AND PATTERSON.

HALF INCH HAIL AND WIND GUSTS UP TO 45 MPH WILL BE POSSIBLE IN THESE
AREAS.

LAT...LON 3589 8157 3596 8159 3603 8146 3590 8138
TIME...MOT...LOC 2230Z 246DEG 12KT 3593 8154

LANE

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
649 PM EDT WED JUN 29 2016

NCZ036-056-292315-
IREDELL NC-CATAWBA NC-
649 PM EDT WED JUN 29 2016

...A STRONG THUNDERSTORM WILL IMPACT SOUTHEASTERN CATAWBA AND SOUTH
CENTRAL IREDELL COUNTIES UNTIL 715 PM EDT...

AT 649 PM EDT...DOPPLER RADAR WAS TRACKING A STRONG THUNDERSTORM 13
MILES SOUTHEAST OF NEWTON...OR NEAR LAKE NORMAN...MOVING EAST AT 15
MPH.

LOCATIONS TO BE IMPACTED INCLUDE...
LAKE NORMAN...MOORESVILLE...SHERRILLS FORD...DOOLIE AND TERRELL.

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

PRECAUTIONARY/PREPAREDNESS ACTIONS...

LAKE NORMAN IS IN THE PATH OF THIS STORM. CLOUD TO GROUND LIGHTNING
AND GUSTY WINDS WILL CREATE DANGEROUS BOATING CONDITIONS.
MOVE TO SHORE IMMEDIATELY.

&&

LAT...LON 3551 8087 3551 8091 3550 8093 3552 8096
      3553 8095 3553 8094 3554 8094 3555 8096
      3555 8104 3563 8104 3563 8086
TIME...MOT...LOC 2249Z 279DEG 14KT 3557 8101

LANE

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
700 PM EDT WED JUN 29 2016

SCZ009-292315-
YORK SC-
700 PM EDT WED JUN 29 2016

...A STRONG THUNDERSTORM WILL IMPACT SOUTHEASTERN YORK COUNTY UNTIL
715 PM EDT...

AT 700 PM EDT...DOPPLER RADAR WAS TRACKING A STRONG THUNDERSTORM 10
MILES SOUTHEAST OF ROCK HILL...OR NEAR CATAWBA...MOVING EAST AT 15
MPH.

LOCATIONS TO BE IMPACTED INCLUDE...
CATAWBA.

HALF INCH HAIL AND WIND GUSTS UP TO 50 MPH WILL BE POSSIBLE IN THESE
AREAS.

LAT...LON 3484 8087 3483 8089 3482 8090 3483 8094
      3489 8092 3490 8088 3487 8088 3486 8087
TIME...MOT...LOC 2300Z 279DEG 13KT 3485 8088

LANE

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
721 PM EDT WED JUN 29 2016

NCZ082-300000-
UNION NC-
721 PM EDT WED JUN 29 2016

...STRONG THUNDERSTORMS WILL IMPACT SOUTHEASTERN UNION COUNTY UNTIL
800 PM EDT...

AT 720 PM EDT...DOPPLER RADAR INDICATED STRONG THUNDERSTORMS ALONG A
LINE EXTENDING FROM 11 MILES NORTH OF WADESBORO TO 8 MILES NORTHEAST
OF MONROE...AND MOVING SOUTHEAST AT 10 MPH.

LOCATIONS TO BE IMPACTED INCLUDE...
UNIONVILLE...WINGATE...MARSHVILLE AND NEW SALEM.

DIME SIZE HAIL AND WIND GUSTS UP TO 50 MPH WILL BE POSSIBLE IN THESE
AREAS.

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 MAY ALSO RISE RAPIDLY. SEEK
HIGHER GROUND IF THREATENED BY FLOOD WATERS. DO NOT DRIVE ACROSS
FLOODED ROADS.

&&

LAT...LON 3493 8031 3490 8041 3509 8053 3514 8028
TIME...MOT...LOC 2320Z 303DEG 10KT 3513 8007 3503 8041

LANE