Severe Thunderstorm Warning 280, NWS Greenville-Spartanburg, SC

938 
WWUS52 KGSP 081847
SVSGSP

Severe Weather Statement
National Weather Service Greenville-Spartanburg SC
247 PM EDT WED AUG 8 2018

SCC073-077-081900-
/O.CON.KGSP.SV.W.0280.000000T0000Z-180808T1900Z/
Pickens SC-Oconee SC-
247 PM EDT WED AUG 8 2018

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 300 PM EDT
FOR SOUTHWESTERN PICKENS AND EAST CENTRAL OCONEE COUNTIES...

At 246 PM EDT, a severe thunderstorm was located 4 miles northeast of
Seneca, moving east at 20 mph.

HAZARD...60 mph wind gusts and penny size hail.

SOURCE...Radar indicated.

IMPACT...Expect damage to trees and power lines.

Locations impacted include...
Clemson, Seneca, Central, Six Mile and Lake Keowee. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Brief damaging winds will blow down trees and power lines over small
areas. A brief period of large hail is also possible. Seek shelter
inside an interior room.

Lake Keowee is in the path of this storm. Get away from the water 
and seek shelter in an interior room in the nearest shelter. If you 
can hear thunder, you are close enough to be struck by lightning.

Please report damaging winds, hail, or flooding to the National
Weather Service Greenville-Spartanburg by calling toll free, 1, 800,
2 6 7, 8 1 0 1, or by posting on our Facebook page, or Tweet it using
hashtag nwsgsp. Your message should describe the event and the
specific location where it occurred.

&&

LAT...LON 3469 8301 3485 8297 3490 8277 3468 8276
      3467 8279
TIME...MOT...LOC 1846Z 283DEG 17KT 3474 8291 

HAIL...0.75IN
WIND...60MPH
 
$$

08

722 
WWUS52 KGSP 081853
SVSGSP

Severe Weather Statement
National Weather Service Greenville-Spartanburg SC
253 PM EDT WED AUG 8 2018

SCC073-077-081903-
/O.EXP.KGSP.SV.W.0280.000000T0000Z-180808T1900Z/
Pickens SC-Oconee SC-
253 PM EDT WED AUG 8 2018

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHWESTERN PICKENS AND EAST
CENTRAL OCONEE COUNTIES WILL EXPIRE AT 300 PM EDT...
                
The storm which prompted the warning has weakened below severe
limits, and no longer poses an immediate threat to life or property.
Therefore the warning will be allowed to expire.

If you observed large hail or wind damage, please report it to the
National Weather Service Greenville-Spartanburg by calling toll free,
1, 800, 2 6 7, 8 1 0 1, or by posting on our Facebook page, or Tweet
it using hashtag nwsgsp. Your message should describe the event and
the specific location where it occurred.

LAT...LON 3469 8301 3485 8297 3490 8277 3468 8276
      3467 8279
TIME...MOT...LOC 1853Z 282DEG 19KT 3472 8289 

$$

08

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
1055 AM EDT Wed Aug 8 2018

.SYNOPSIS...
Weak high pressure will persist over the area today, but with weak
upper-level disturbances arriving from the west this afternoon and
evening. A cold front will then approach from the northwest tonight
into Thursday and stall somewhere in or near the forecast area
through late week. Seasonably warm temperatures and scattered to
numerous afternoon and evening showers and thunderstorms will
continue through the end of the week. The front will persist in the
vicinity through the weekend, with deeper moisture returning from
the south for the latter half of the weekend into early next week.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 1045 AM...Forecast is on track per latest obs and the various
CAMs. The 12z GSO sounding shows potential for over 2000 J/kg of
CAPE. Skies have cleared out for most of the CWFA, and strong
insolation should result in highs in the lower 90s this aftn. So we
still expect moderate to strong instability this aftn with enough
flow to carry storms along. Convection should be triggered by
outflows across TN and mountain-top convergence early this aftn,
then drift west across the rest of the CWFA late aftn into early
evening. Only minor tweaks were needed to the temps and PoP grids
with this update. Severe threat still looks marginal, for mainly
damaging winds. But cannot rule out isolated large hail. Activity
should wane/exit east by late evening per model consensus. PoPs will
linger in the NC mountains due to persistent westerly upslope flow
and a digging trough aloft.

Previous discussion...
Still expect little airmass change today with PWATs remaining
between 1.75-2" and light SWly flow continuing through the day.
Afternoon instability will also be similar to previous days, a
moderate 2000-2500 J/kg. The main difference with today will be some
upper support arriving near the peak of diurnal convection as a
shortwave rounds the base of an approaching upper trough. More stout
SWly flow aloft will also set up through the day and the approaching
frontal boundary will provide a low-level convergence zone,
suggesting that severe potential (storms containing strong winds in
particular) will be greater today that the past few days. CIPS
analogs indicate increased level and coverage of severe
probabilities this afternoon as well. With deep-layer effective
shear on the order of 25-30kt, expect some clusters/linear
organization will be the most likely mode of convection after early
afternoon convective initiation in the higher terrain. With the best
upper support probably arriving close to 00Z, have also extended
elevated pops later into the evening across the NC mountains and
Piedmont areas, agreeing with trends in updraft strength/coverage
seen in the 00Z HREF. Having said all that, new SPC day 1 marginal
risk looks well-placed.

The only other concern for the near term would be hydro...the WPC
day 1 marginal risk for the mountainous parts of our area seems
reasonable considering high PWATs, upper support, and good
convective coverage in the afternoon and evening hours. Though
storms this afternoon should be moving at a pretty good clip,
rainfall rates could become an issue with any convection that does
develop. Given that, isolated hydro issues can't be ruled out
anywhere in our forecast area.

&&

.SHORT TERM /THURSDAY THROUGH SATURDAY/...
As of 230 AM EDT Wednesday: The numerical models feature relatively
good agreement on the upper flow pattern for Thursday through
Friday. A decent shortwave is expected to carve out across MO/AR
Thursday and then move east across TN/KY through Friday, and finally
through the southern Appalachians Friday night through Saturday.
Meanwhile, a surface front will remain stalled somewhere in or near
the southern tier of the forecast area. Very little drying is
expected with the frontal boundary and lingering boundary layer
moisture will fire mainly diurnal showers and thunderstorms each day
- with a mainly mountain focus. Instability could be a bit less on
Friday and Saturday, but the forcing will be better with the
approaching/passing wave. Continued high humidity will push heat
index values to 95 or better across the southeast half each
afternoon despite slightly cooler maximum temperatures than observed
earlier in the week.

&&

.LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...
As of 245 AM EDT Wednesday: A closed upper low pressure system
developing over the southern shores of the Great Lakes on Sunday
will amplify an associated trough axis between the MS River Valley
and the Appalachians on Monday. The improved southerly flow should
permit precipitable water values to peak in the Sunday to Monday
timeframe, with the greatest associated risk of flooding. The peak
wind shear should be Monday afternoon just ahead of the upper trough
axis, but confidence on the timing is too low to pin down a severe
thunderstorm threat just yet. Model differences increase Monday
night through Tuesday on how quickly the base of the trough crosses
our region, but with the GFS now trending toward the more
progressive ECMWF solution. This would promote some modest drying on
Tuesday. Expect continued above climo PoPs Sunday and Monday, as
well as near normal maxes and above normal mins through the period.

&&

.AVIATION /15Z WEDNESDAY THROUGH SUNDAY/...
At KCLT and elsewhere: With little change in airmass this AM from
the past few nights, mountain restrictions are likely through the
morning, with a very small chance of some patchy MVFR fog at all
other sites for the next couple hours. KAVL has already been
bouncing from MVFR to LIFR cigs and vis this morning, and expect the
more pessimistic conditions to dominate until around 13Z.
Thunderstorms will make an appearance again this afternoon, most
likely with greater coverage and intensity than past days.
Therefore, all sites feature a PM tempo for TSRA. Surface winds will
increase slightly during the day as well, with more prevailing
southwesterly flow of near 5 kts and higher gusts expected in any
thunderstorms or thunderstorm outflows.

Outlook: Typical mid-summer conditions are fcst the next several
days. Diurnal, scattered thunderstorms will continue mainly in the
afternoons, with coverage increasing toward the weekend. Associated
morning restrictions will be possible each day, especially in
mountain valleys.

Confidence Table...

            15-21Z        21-03Z        03-09Z        09-12Z
KCLT       High 100%     High 100%     High 100%     High 100%
KGSP       High 100%     High 100%     High 100%     High 100%
KAVL       High 100%     High 100%     High 100%     Med   78%
KHKY       High 100%     High 100%     High 100%     High 100%
KGMU       High 100%     High 100%     High 100%     High 100%
KAND       High 100%     High 100%     High 100%     High  88%

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:

www.weather.gov/gsp/aviation

&&

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

&&

SYNOPSIS...HG
NEAR TERM...ARK/Carroll
SHORT TERM...HG
LONG TERM...HG
AVIATION...Carroll

Hazardous Weather Outlook
National Weather Service Greenville-Spartanburg SC
439 AM EDT Wed Aug 8 2018

NCZ033-048>053-058-059-062>065-501>507-509-090845-
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-
Polk Mountains-
439 AM EDT Wed Aug 8 2018

This Hazardous Weather Outlook is for the mountains and northern
foothills of western North Carolina.

.DAY ONE...Today and tonight.

Thunderstorms will develop across the mountains by early afternoon
and increase in coverage before racing east through early evening.
Any of these thunderstorms will have the potential to produce cloud-
to-ground lightning, gusty winds, and heavy rainfall. Isolated
flooding may develop in any locations impacted by multiple showers.
In addition, a few of the thunderstorms could become severe this
afternoon, with damaging wind gusts being the primary threat.

.DAYS TWO THROUGH SEVEN...Thursday through Tuesday.

Thunderstorm coverage will remain fairly high each afternoon and
evening from Thursday through next Monday. The main impacts will be
cloud-to-ground lightning, heavy rainfall, and gusty winds. Isolated
flooding will be possible each day as the rainfall totals accrue.

.SPOTTER INFORMATION STATEMENT...

Spotters are requested to forward any reports of large hail,
damaging winds, tornadoes, or flash flooding to our office.

GAZ010-017-018-026-028-029-NCZ035>037-056-057-068>072-082-508-510-
SCZ001>014-019-090845-
Rabun-Habersham-Stephens-Franklin-Hart-Elbert-Alexander-Iredell-
Davie-Catawba-Rowan-Cleveland-Lincoln-Gaston-Mecklenburg-Cabarrus-
Union-Greater Rutherford-Eastern Polk-Oconee Mountains-
Pickens Mountains-Greenville Mountains-Greater Oconee-
Greater Pickens-Greater Greenville-Spartanburg-Cherokee-York-
Anderson-Abbeville-Laurens-Chester-Greenwood-
439 AM EDT Wed Aug 8 2018

This Hazardous Weather Outlook is for northeast Georgia, the piedmont
and southern foothills of western North Carolina, and Upstate South
Carolina.

.DAY ONE...Today and tonight.

Scattered to numerous thunderstorms will develop from the west this
afternoon and then race eastward across the piedmont through the
evening hours. Any of these thunderstorms will have the potential to
produce frequent cloud-to-ground lightning, gusty winds, and heavy
rainfall. Isolated flooding may develop in any locations impacted by
multiple showers or thunderstorms. In addition, a few of the
thunderstorms could become severe this afternoon and evening, with
damaging wind gusts being the primary threat.

In addition, Heat Index values should reach 95 to 100 degrees this
afternoon and evening.

.DAYS TWO THROUGH SEVEN...Thursday through Tuesday.

Thunderstorm coverage will remain fairly high each afternoon and
evening from Thursday through next Monday. The main impacts will be
cloud-to-ground lightning, heavy rainfall, and gusty winds. Isolated
flooding will be possible each day as the rainfall totals accrue.

Heat Index values of 95 to 100 will be likely once again on
Thursday.

.SPOTTER INFORMATION STATEMENT...

Spotters are requested to forward any reports of large hail,
damaging winds, tornadoes, or flash flooding to our office.

HG

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
128 PM EDT WED AUG 8 2018

GAZ010-SCZ001-081800-
Rabun GA-Oconee Mountains SC-
128 PM EDT WED AUG 8 2018

...A STRONG THUNDERSTORM WITH INTENSE LIGHTNING WILL IMPACT CENTRAL
RABUN AND NORTHWESTERN OCONEE COUNTIES UNTIL 200 PM EDT...

At 127 PM EDT, Doppler radar was tracking a strong thunderstorm with
intense lightning near Clayton, moving east at 20 mph.

Locations to be impacted include...
Clayton, Walhalla, Mountain City, Tiger, Lakemont, Oconee State Park,
Black Rock Mountain State Park, Mountain Rest, Long Creek and Pine
Mountain.

In addition to intense lightning, wind gusts up to 45 mph and half
inch hail will be possible in these areas.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Frequent lightning is occurring with this storm. If outdoors, try to
get indoors or into a hard topped vehicle. Otherwise, stay away from
open areas and isolated high objects such as trees. When indoors,
stay away from windows and doors and avoid using wired electronic
devices. Do not take a shower or bath. Try to unplug unnecessary
appliances before the storm approaches.

&&

LAT...LON 3500 8313 3500 8311 3501 8308 3474 8307
      3478 8348 3494 8349
TIME...MOT...LOC 1727Z 267DEG 17KT 3487 8337

LANE

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
135 PM EDT WED AUG 8 2018

GAZ010-017-SCZ001-081800-
Rabun GA-Habersham GA-Oconee Mountains SC-
135 PM EDT WED AUG 8 2018

...A STRONG THUNDERSTORM WILL IMPACT NORTHEASTERN HABERSHAM...
SOUTHWESTERN RABUN AND WEST CENTRAL OCONEE COUNTIES UNTIL 200 PM
EDT...

At 135 PM EDT, Doppler radar was tracking a strong thunderstorm 8
miles south of Clayton, or near Lake Rabun, moving east at 25 mph.

Locations to be impacted include...
Tallulah Falls, Lake Rabun, Lakemont, Tallulah Gorge State Park, Seed
Lake, Turnerville and Long Creek.

Wind gusts up to 45 mph and half inch hail will be possible in these
areas.

LAT...LON 3479 8354 3477 8323 3464 8320 3466 8330
      3467 8331 3467 8332 3468 8332 3468 8334
      3469 8334 3467 8337 3470 8354
TIME...MOT...LOC 1735Z 270DEG 22KT 3475 8343

LANE

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
149 PM EDT WED AUG 8 2018

NCZ048-052-053-081815-
Buncombe NC-Haywood NC-Madison NC-
149 PM EDT WED AUG 8 2018

...A STRONG THUNDERSTORM WILL IMPACT SOUTHWESTERN MADISON...
NORTHEASTERN HAYWOOD AND WEST CENTRAL BUNCOMBE COUNTIES UNTIL 215 PM
EDT...

At 149 PM EDT, Doppler radar was tracking a strong thunderstorm 11
miles southwest of Marshall, or 7 miles west of Leicester, moving
east at 20 mph.

Locations to be impacted include...
Leicester, Luck and Canto.

Wind gusts up to 45 mph and half inch hail will be possible in these
areas.

LAT...LON 3564 8292 3574 8290 3573 8263 3556 8267
TIME...MOT...LOC 1749Z 281DEG 16KT 3567 8282

LANE

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
153 PM EDT WED AUG 8 2018

NCZ059-062-063-081830-
Southern Jackson NC-Northern Jackson NC-Macon NC-
153 PM EDT WED AUG 8 2018

...A STRONG THUNDERSTORM WILL IMPACT EAST CENTRAL MACON AND
SOUTHWESTERN JACKSON COUNTIES UNTIL 230 PM EDT...

At 153 PM EDT, Doppler radar was tracking a strong thunderstorm near
Franklin, moving east at 20 mph.

Locations to be impacted include...
Franklin, Ellijay, Lake Glenville, and Cullasaja.

Wind gusts up to 40 mph and pea size hail will be possible in these
areas.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Lake Glenville 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 3514 8342 3524 8344 3527 8318 3511 8316
TIME...MOT...LOC 1753Z 265DEG 16KT 3518 8335

LANE

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
204 PM EDT WED AUG 8 2018

SCZ001-002-004-005-081830-
Pickens Mountains SC-Greater Pickens SC-Greater Oconee SC-
Oconee Mountains SC-
204 PM EDT WED AUG 8 2018

...A STRONG THUNDERSTORM WILL IMPACT SOUTHWESTERN PICKENS AND EAST
CENTRAL OCONEE COUNTIES UNTIL 230 PM EDT...

At 204 PM EDT, Doppler radar was tracking a strong thunderstorm 4
miles east of Walhalla, moving east at 20 mph.

Locations to be impacted include...
Walhalla, Lake Keowee and Six Mile.

Wind gusts up to 45 mph and half inch hail will be possible in these
areas.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Lake Keowee 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 3473 8308 3484 8309 3488 8283 3471 8282
TIME...MOT...LOC 1804Z 265DEG 16KT 3478 8299

LANE

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
211 PM EDT WED AUG 8 2018

NCZ510-SCZ007-081845-
Eastern Polk NC-Spartanburg SC-
211 PM EDT WED AUG 8 2018

...A STRONG THUNDERSTORM WILL IMPACT SOUTH CENTRAL POLK AND NORTHERN
SPARTANBURG COUNTIES UNTIL 245 PM EDT...

At 210 PM EDT, Doppler radar was tracking a strong thunderstorm 5
miles southeast of Columbus, or near Landrum, moving east at 10 mph.

Locations to be impacted include...
Landrum and Green Creek.

Wind gusts up to 45 mph and pea size hail will be possible in these
areas.

LAT...LON 3516 8219 3520 8220 3524 8206 3513 8205
TIME...MOT...LOC 1810Z 269DEG 8KT 3518 8215

LANE