Severe Thunderstorm Warning 118, NWS Greenville-Spartanburg, SC

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
227 PM EDT Sun Jun 17 2018

.SYNOPSIS...
Hot high pressure will build atop the region through the middle of
the week. Scattered afternoon and evening thunderstorms are expected
each day, focusing over the mountains. Moisture will increase
towards the end of next week as a weak frontal boundary sags toward
the area.

&&

.NEAR TERM /THROUGH MONDAY/...
As of 2pm EDT Sunday:  High pressure will dominate the weather for
the near term and beyond with a Bermuda high off the coast and an
upper ridge over the Eastern CONUS.  The only change for the next 24
hours will be an increase in the strength of a surface trough east
of the Appalachians that modifies the otherwise broad area of high
pressure over the SE CONUS.  This weak trough will modify surface
wind direction, but do little else, with winds remaining light and
somewhat variable.  Moisture and unseasonably warm to hot afternoon
temperatures will continue with heat indexes reaching the mid to
upper 90s this afternoon and on Monday.  Warm temperatures aloft
will limit CAPE development in the afternoons, and some increase in
the strength of the capping inversion is also anticipated.  This
will limit intensity of thunderstorm activity and confine initiation
to the mountains.  Any storms that do develop have the potential for
brief low-end severe wind gusts.  CAMs mostly have convective
showers confined to the mountains, with the HRRR having a couple
spots of convection in piedmont areas with weak updrafts.  Have,
thus, de-emphasized thunderstorms in piedmont areas this afternoon
and tomorrow.

&&

.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
As of 215 PM Sunday: Strong upper ridging will remain in place
across the western Carolinas and northeast Georgia through Tuesday.
Winds will be very light up the column and this minimal steering
flow should keep convection mainly over mountain sections, where
slow-movers will create an isolated heavy rainfall threat with any
downpours that develop. Additional triggering will be possible east
of the mountains in weak lee trough convergence, but coverage will
be more isolated in nature there. Very warm mid-level temps should
keep severe weather to a minimum. Expect plenty of 100 to 104 heat
index values east of the mountains, and a few piedmont locations
could flirt with 105 if dewpoints do not mix sufficiently.

Height falls across the northern tier will improve the westerlies
slightly over the region on Wednesday. Weak vorticity lobes riding
over the southeast ridge could aid diurnal triggering Wednesday
afternoon, but continued warm mid-level profiles will inhibit most
of the severe potential. Westerly downsloping will improve warming
east of the mountains, and there could be slightly better dewpoint
pooling south of the frontal boundary through the Virginias late
Wednesday. Expect another afternoon of heat index values rising into
the 100 to 105 range. The HWO mention will continue even though Heat
Advisories are currently looking a bit marginal.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
As of 200 PM EDT Sunday: The medium range remains dominated by hot
and humid conditions and a diurnal pattern of showers and
thunderstorms each day. By the time the extended period picks up 00Z
Thursday, the strong upper ridging over the SE CONUS will be in the
process of waning while a large upper trough digs into the eastern
CONUS. A frontal boundary will slowly sag southward as this trough
descends, finally making it into our area by Friday. Some moisture
will accompany the boundary, which will serve as a focus for diurnal
convection, especially Friday and Saturday. Guidance then suggests
that an upper low/trough will swing into the central Plains and
drive another frontal boundary towards the area over the weekend.
This should enhance the pattern of diurnal showers and
thunderstorms, increasing not only the likelihood but also the
coverage through the end of the week and into the weekend.

Temperatures will remain hot on Thursday with dew point likely only
mixing out to the highs 60s at best in the afternoon hours, meaning
another day of heat indices flirting with advisory criteria. Heights
will fall just enough on Friday through the weekend for max temps to
drop to within 5 degrees of normal. Min temps will remain above
average through the period.

&&

.AVIATION /19Z SUNDAY THROUGH FRIDAY/...
At KCLT and elsewhere:  High pressure will dominate the weather at
least through Monday, with generally light and variable winds and
mostly clear skies.  There is some chance for afternoon
thunderstorms today, but an increase in the strength of the capping
inversion will restrict storms mostly, if not entirely, to the
mountains, with some afternoon fair-weather cu elsewhere.  Weak
surface troughing east of the Appalachians will modify the otherwise
broad Bermuda high, and give a southwesterly component to the winds,
when they are not variable.  Some patchy fog is also possible
overnight in some areas in the mountains.

Outlook: Typical summertime potential for diurnally-driven showers
and thunderstorms will persist into midweek, thanks to a large upper
level ridge, bringing hot and humid conditions. Some morning fog will
also be possible in the mountain valleys and over lakes each day.
Chances for precip look greater late in the week as the ridge begins
to break down.

Confidence Table...

            18-24Z        00-06Z        06-12Z        12-18Z
KCLT       High 100%     High 100%     High 100%     High 100%
KGSP       High 100%     High 100%     High 100%     High 100%
KAVL       High 100%     High 100%     High 100%     High 100%
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 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:

www.weather.gov/gsp/aviation

&&

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

&&

SYNOPSIS...Carroll
NEAR TERM...WJM
SHORT TERM...HG
LONG TERM...Carroll
AVIATION...WJM

Hazardous Weather Outlook
National Weather Service Greenville-Spartanburg SC
610 AM EDT Sun Jun 17 2018

GAZ010-017-018-026-028-NCZ033-035-036-048>053-056-058-059-062>065-
068>070-501>510-SCZ001>008-010-181015-
Rabun-Habersham-Stephens-Franklin-Hart-Avery-Alexander-Iredell-
Madison-Yancey-Mitchell-Swain-Haywood-Buncombe-Catawba-Graham-
Northern Jackson-Macon-Southern Jackson-Transylvania-Henderson-
Cleveland-Lincoln-Gaston-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-Anderson-
610 AM EDT Sun Jun 17 2018

This Hazardous Weather Outlook is for northeast Georgia, piedmont
North Carolina, western North Carolina and upstate South Carolina.

.DAY ONE...Today and Tonight.

Isolated to scattered thunderstorms are expected to develop across
the area this afternoon into this evening, with the highest coverage
expected across the mountains. While the main threats will be from
occasional cloud-to-ground lightning and locally heavy rainfall, an
isolated severe storm or two could produce brief damaging winds and
perhaps large hail. Locally heavy rainfall could cause isolated
flooding as well.

.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.

GAZ029-NCZ037-057-071-072-082-SCZ009-011>014-019-181015-
Elbert-Davie-Rowan-Mecklenburg-Cabarrus-Union-York-Abbeville-Laurens-
Chester-Greenwood-
610 AM EDT Sun Jun 17 2018

This Hazardous Weather Outlook is for northeast Georgia, piedmont
North Carolina and upstate South Carolina.

.DAY ONE...Today and Tonight.

Isolated to widely scattered thunderstorms are expected to develop
across the area this afternoon into this evening, with the highest
coverage expected across the mountains. While the main threats will
be from occasional cloud-to-ground lightning and locally heavy
rainfall, an isolated severe storm or two could produce brief
damaging winds and perhaps large hail. Locally heavy rainfall could
cause isolated flooding as well.

.DAYS TWO THROUGH SEVEN...Monday through Saturday.

..Monday...No hazardous weather is expected at this time.
..Tuesday...Excessive heat possible. Heat Index values will reach
100 to 105 degrees.
..Wednesday...Excessive heat possible. Heat Index values will reach
100 to 105 degrees.
..Thursday...Excessive heat possible. Heat Index values will reach
100 to 105 degrees.
..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
135 PM EDT SUN JUN 17 2018

NCZ053-171800-
Buncombe NC-
135 PM EDT SUN JUN 17 2018

...A STRONG THUNDERSTORM WILL IMPACT SOUTHEASTERN BUNCOMBE COUNTY
UNTIL 200 PM EDT...

At 134 PM EDT, Doppler radar was tracking a strong thunderstorm 6
miles southeast of Downtown Asheville, or near the Blue Ridge
Parkway at the NC Arboretum, moving southwest at 10 mph.

Locations to be impacted include...
Downtown Asheville, East Asheville, Arden, West Asheville, Swannanoa,
Fairview In Buncombe County, Biltmore Forest, Bent Creek, Asheville
Airport and East Asheville.

Wind gusts up to 35 mph, pea size hail, and very heavy rainfall
rates up to 1 inch per hour will be possible in these areas.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Gusty winds can blow down trees that are dead, or that have weakened
root systems. Outdoor furniture and similar items can be tossed
around if not anchored. Seek shelter indoors.

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.

&&

LAT...LON 3555 8228 3550 8233 3548 8237 3546 8237
      3547 8242 3545 8247 3545 8253 3543 8253
      3542 8254 3544 8255 3543 8257 3544 8261
      3544 8262 3552 8270 3570 8241
TIME...MOT...LOC 1734Z 044DEG 12KT 3554 8246

HG

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
216 PM EDT SUN JUN 17 2018

NCZ048-053-171845-
Buncombe NC-Madison NC-
216 PM EDT SUN JUN 17 2018

...A STRONG THUNDERSTORM WILL IMPACT SOUTHERN MADISON AND
NORTHWESTERN BUNCOMBE COUNTIES UNTIL 245 PM EDT...

At 215 PM EDT, Doppler radar was tracking a strong thunderstorm 6
miles south of Marshall, or 4 miles northeast of Leicester, moving
northwest at 25 mph.

Locations to be impacted include...
Marshall, Woodfin, Weaverville, Mars Hill, Leicester, Walnut, Canto
and Spring Creek.

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

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Gusty winds can blow down trees that are dead, or that have weakened
root systems. Outdoor furniture and similar items can be tossed
around if not anchored. Seek shelter indoors.

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.

&&

LAT...LON 3572 8244 3558 8268 3580 8286 3594 8258
TIME...MOT...LOC 1815Z 143DEG 23KT 3571 8266

Carroll

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
233 PM EDT SUN JUN 17 2018

NCZ033-049-050-501-171900-
Yancey NC-Caldwell Mountains NC-Mitchell NC-Avery NC-
233 PM EDT SUN JUN 17 2018

...A STRONG THUNDERSTORM WILL IMPACT CENTRAL MITCHELL...NORTHWESTERN
CALDWELL...AVERY AND NORTHEASTERN YANCEY COUNTIES UNTIL 300 PM EDT...

At 233 PM EDT, Doppler radar was tracking a strong thunderstorm near
Newland, or near Elk Park. This storm was nearly stationary.

Locations to be impacted include...
Newland, Blowing Rock In Caldwell County, Banner Elk, Elk Park,
Bakersville, Crossnore, Sugar Mountain, Seven Devils, Grandfather
Mountain State Park and B.R. Parkway-Linville Falls To Grandfather.

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

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Gusty winds can blow down trees that are dead, or that have weakened
root systems. Outdoor furniture and similar items can be tossed
around if not anchored. Seek shelter indoors.

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 3616 8183 3611 8181 3612 8169 3612 8155
      3609 8147 3592 8223 3607 8235 3612 8214
      3611 8213 3610 8208 3613 8205 3612 8203
      3616 8201 3619 8186
TIME...MOT...LOC 1833Z 122DEG 4KT 3613 8195

Carroll