Special Weather Statement, NWS Greenville-Spartanburg, SC

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
228 PM EDT Sat Aug 7 2021

.SYNOPSIS...
As an upper level disturbance moves off the East Coast tonight,
drier high pressure builds into the area Sunday.  This will bring
the return of typical summertime weather across the region through
the start of the week. Moisture and the chances for showers and
thunderstorms return for the middle of the week.

&&

.NEAR TERM /THROUGH SUNDAY/...
As of 228 PM: Scattered/numerous showers and storms have
developed over the mtns/foothills this afternoon, as predicted,
as a mid/upper trof axis moves overhead. The environment has
sfc-based CAPE on the order of 1500-2500 J/kg, which will be
sufficient to fuel additional storms. Shear is modest at best,
but probably enough to afford some weak organization into the
late afternoon, especially if some outflows can consolidate off
the higher terrain. The mesoanalysis shows just enough dCAPE
above 800 J/kg to make the storms interesting, so a few
strong/severe outflow winds will not be ruled out. Chances will
diminish this evening diurnally and as a shortwave axis passes
east. Precipitable water has not tailed off as quick as
expected, and storm motion vectors are fairly short, so we can't
rule out additional excessive rainfall.

After the upper trof passes later this evening, sky should clear
and wind should go light/variable as high pressure settles over
the mtns, setting up a good potential for fog development in the
pre-dawn hours, particularly where rain falls this afternoon. Low
temps will be about a category below normal. Sunday should be a
fairly quiet day with weak high pressure hanging around. High temps
will be right around normal for early August. In the absence of
anything to actively discourage convection, we should see widely
scattered showers over the mtns and foothills in the afternoon.

&&

.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
As of 100 PM EDT Saturday...Upper ridging dominates across the FA
thru the short term as an h5 trof approaches yet attenuates across
ern TN by Tue. With a classic Atl sfc ridge config, winds will align
generally sw/ly thru the period and maintain high td/s and allow
for weak temp adv within the BL. This will generate low-end sbCAPE
values arnd 1000 J/kg breaking a mlvl cap each afternoon wihin very
weak column flow. Thus, expect diurnally driven pulse and outflow
driven storms each afternoon, a few a which may briefly become quite
strong. Max and min temps will remain arnd normal each day.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
As of 145 PM EDT Saturday...The ext range continues to show good
confidence in the overall pattern. Expect subTrop ridging to
dominate with any sigfnt upper waves remaining well north of the FA.
This will continue normal summertime wx over the region with similar
fcsts for each day. Little column flow along with skinny sbCAPE
depicted by the models, will lead to non/organized thunderstorms
each afternoon with increasing PWATS as a weak sfc front settles in
from the NW. With slow moving or perhaps anchored storms, there may
be some localized hydro issues, mainly confined to the mtns where
the better chance of deep convec is likely. Surface td/s will remain
high and along with temps at or a little abv normal, expect muggy
conds each day.

&&

.AVIATION /19Z SATURDAY THROUGH THURSDAY/...
At KCLT and Elsewhere...Prevailing VFR outside of thunderstorms
through the evening hours. First concern is thunderstorm activity
associated with an upper trof. Storms already developed over the
mtns will affect KAVL first, then will move east of the Blue Ridge
during the late afternoon/early evening. Will employ a TEMPO to
handle the associated restrictions. The storms should end by 01Z at
the latest. Clearing sky this evening, combined with light winds,
will set up a fog scenario in the pre-dawn hours tonight. Visibility
will probably drop lowest in places that experience rainfall late
today. For the time being, prevailing MVFR visibility will be used
as a placeholder starting from 06Z to 08Z. We will eventually add
a TEMPO group at some locations for possible IFR/LIFR conditions
as confidence increases. The fog should burn off quickly Sunday
morning, after which only scattered low clouds are expected with
a light wind. A few showers are possible Sunday afternoon, but
the chances are too low to mention at this time.

Outlook: Diurnal shower/thunderstorm activity will return for
the first part of next week. Fog and low stratus will be possible
each morning, particularly over the mtn valleys and areas primed
by rainfall from the previous evening.

Confidence Table...

            18-24Z        00-06Z        06-12Z        12-18Z
KCLT       High  99%     High 100%     High 100%     High 100%
KGSP       High 100%     High 100%     High  94%     High 100%
KAVL       High 100%     High 100%     Med   71%     High  88%
KHKY       High 100%     High 100%     High  95%     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 are available at
the following link:

www.weather.gov/gsp/aviation

&&

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

&&

SYNOPSIS...DEO
NEAR TERM...PM
SHORT TERM...SBK
LONG TERM...SBK
AVIATION...PM

Hazardous Weather Outlook
National Weather Service Greenville-Spartanburg SC
336 PM EDT Sat Aug 7 2021

GAZ010-017-018-026-028-029-NCZ033-035>037-048>053-056>059-062>065-
068>072-082-501>510-SCZ001>014-019-081945-
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 NC-
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-Union SC-Chester-Greenwood-
336 PM EDT Sat Aug 7 2021

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 to numerous showers and thunderstorms will impact the
western Carolinas and northeast Georgia late this afternoon through
early this evening. Locally heavy rainfall and isolated flooding will
be the primary threat. However, these thunderstorms will also be
capable of producing dangerous lightning, small hail, and very gusty
to damaging winds.

.DAYS TWO THROUGH SEVEN...Sunday through Friday.

No hazardous weather is expected at this time.

.SPOTTER INFORMATION STATEMENT...

None.

HG

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
451 PM EDT Sat Aug 7 2021

NCZ033-050-503>506-072130-
McDowell Mountains NC-Burke Mountains NC-Greater Burke NC-
Eastern McDowell NC-Avery NC-Mitchell NC-
451 PM EDT Sat Aug 7 2021

...A strong thunderstorm will impact portions of northeastern
McDowell, southeastern Mitchell, southwestern Avery and northwestern
Burke Counties through 530 PM EDT...

At 450 PM EDT, Doppler radar was tracking a strong thunderstorm near
Spruce Pine, moving southeast at 15 mph.

HAZARD...Winds in excess of 40 mph and pea size hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects. Minor damage to outdoor objects is
         possible.

Locations impacted include...
Spruce Pine, Lake James State Park, Table Rock, Linville Falls, Lake
James, B.R. Parkway-Linville Falls To Grandfather, Nebo, Ingalls,
Altamont and Ashford.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Torrential rainfall is also occurring with this storm and may lead to
localized flooding. Do not drive your vehicle through flooded
roadways.

&&

LAT...LON 3596 8180 3595 8180 3595 8178 3593 8178
      3593 8175 3589 8173 3587 8170 3565 8192
      3589 8215 3591 8214 3592 8215 3593 8215
      3594 8218 3602 8207 3603 8197
TIME...MOT...LOC 2050Z 306DEG 15KT 3594 8204

MAX HAIL SIZE...0.25 IN
MAX WIND GUST...40 MPH

JPT

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
453 PM EDT Sat Aug 7 2021

NCZ048-049-053-505-072130-
Buncombe NC-McDowell Mountains NC-Yancey NC-Madison NC-
453 PM EDT Sat Aug 7 2021

...A strong thunderstorm will impact portions of west central
McDowell, southeastern Madison, eastern Buncombe and southern Yancey
Counties through 530 PM EDT...

At 452 PM EDT, Doppler radar was tracking a strong thunderstorm 11
miles southwest of Burnsville, or 7 miles east of Mars Hill, moving
southeast at 15 mph.

HAZARD...Winds in excess of 40 mph and pea size hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects. Minor damage to outdoor objects is
         possible.

Locations impacted include...
Black Mountain, Swannanoa, Weaverville, Mars Hill, Mount Mitchell
State Park, B.R. Parkway-East Asheville To Craggy Gardens, B.R.
Parkway-Craggy To Little Switzerland, Warren Wilson College, Fairview
In Buncombe County and Montreat.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Torrential rainfall is also occurring with this storm and may lead to
localized flooding. Do not drive your vehicle through flooded
roadways.

&&

LAT...LON 3576 8265 3584 8257 3592 8243 3591 8234
      3574 8205 3550 8236
TIME...MOT...LOC 2052Z 306DEG 15KT 3579 8243

MAX HAIL SIZE...0.25 IN
MAX WIND GUST...40 MPH

JPT

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
507 PM EDT Sat Aug 7 2021

SCZ007-008-013-072145-
Cherokee SC-Union SC-Spartanburg SC-
507 PM EDT Sat Aug 7 2021

...A strong thunderstorm will impact portions of southeastern
Spartanburg, southwestern Cherokee and northwestern Union Counties
through 545 PM EDT...

At 507 PM EDT, Doppler radar was tracking a strong thunderstorm near
Spartanburg, or over Cedar Springs, moving southeast at 20 mph.

HAZARD...Winds in excess of 40 mph and small hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects. Minor damage to outdoor objects is
         possible.

Locations impacted include...
Spartanburg, Pacolet, Roebuck, Jonesville, Pacolet Mills, Croft State
Park, Cedar Springs, Moore, Buffalo and Pauline.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Torrential rainfall is also occurring with this storm and may lead to
localized flooding. Do not drive your vehicle through flooded
roadways.

&&

LAT...LON 3488 8204 3502 8192 3492 8156 3466 8176
TIME...MOT...LOC 2107Z 300DEG 15KT 3491 8190

MAX HAIL SIZE...0.25 IN
MAX WIND GUST...40 MPH

JPT

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
521 PM EDT Sat Aug 7 2021

NCZ033-501>504-072200-
Caldwell Mountains NC-Burke Mountains NC-Greater Burke NC-
Greater Caldwell NC-Avery NC-
521 PM EDT Sat Aug 7 2021

...A strong thunderstorm will impact portions of central Caldwell,
southeastern Avery and north central Burke Counties through 600 PM
EDT...

At 521 PM EDT, Doppler radar was tracking a strong thunderstorm 10
miles southwest of Blowing Rock, or 7 miles southeast of B.R.
Parkway-Linville Falls To Grandfather, moving southeast at 20 mph.

HAZARD...Winds in excess of 40 mph and pea size hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects. Minor damage to outdoor objects is
         possible.

Locations impacted include...
Lenoir, Gamewell, Cajah's Mountain, Cedar Rock, Drexel, Valdese,
Hudson, Lake Rhodhiss, Edgemont and Collettsville.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Torrential rainfall is also occurring with this storm and may lead to
localized flooding. Do not drive your vehicle through flooded
roadways.

&&

LAT...LON 3597 8188 3610 8177 3599 8141 3574 8158
TIME...MOT...LOC 2121Z 303DEG 16KT 3599 8176

MAX HAIL SIZE...0.25 IN
MAX WIND GUST...40 MPH

JPT

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
532 PM EDT Sat Aug 7 2021

NCZ052-053-064-065-072215-
Buncombe NC-Transylvania NC-Haywood NC-Henderson NC-
532 PM EDT Sat Aug 7 2021

...A strong thunderstorm will impact portions of north central
Transylvania, northwestern Henderson, east central Haywood and
southwestern Buncombe Counties through 615 PM EDT...

At 532 PM EDT, Doppler radar was tracking a strong thunderstorm 9
miles west of Downtown Asheville, or 4 miles west of Enka, moving
southeast at 10 mph.

HAZARD...Winds in excess of 40 mph and pea size hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects. Minor damage to outdoor objects is
         possible.

Locations impacted include...
Arden, Mills River, Fletcher, Bent Creek, B.R. Parkway-Mount Pisgah
To The Nc Arboretum, Asheville Airport, Mount Pisgah, Skyland, Enka
and Biltmore Forest.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Torrential rainfall is also occurring with this storm and may lead to
localized flooding. Do not drive your vehicle through flooded
roadways.

&&

LAT...LON 3559 8282 3563 8265 3542 8244 3532 8278
TIME...MOT...LOC 2132Z 335DEG 10KT 3556 8272

MAX HAIL SIZE...0.25 IN
MAX WIND GUST...40 MPH

JPT

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
546 PM EDT Sat Aug 7 2021

NCZ052-059-063-064-072230-
Transylvania NC-Haywood NC-Southern Jackson NC-Northern Jackson NC-
546 PM EDT Sat Aug 7 2021

...A strong thunderstorm will impact portions of central
Transylvania, northeastern Jackson and southwestern Haywood Counties
through 630 PM EDT...

At 546 PM EDT, Doppler radar was tracking a strong thunderstorm 4
miles southwest of Waynesville, or near Balsam, moving south at 20
mph.

HAZARD...Winds in excess of 40 mph and pea size hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects. Minor damage to outdoor objects is
         possible.

Locations impacted include...
Waynesville, Balsam, B.R. Parkway-Black Balsam To Mount Pisgah,
Graveyard Fields, B.R. Parkway-Balsam Gap To Black Balsam Area, Black
Balsam Area, Lake Junaluska, B.R. Parkway-Smoky Mountains To Balsam
Gap, Tuckasegee and Sunburst.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 3549 8314 3552 8297 3527 8280 3521 8312
TIME...MOT...LOC 2146Z 344DEG 15KT 3543 8303

MAX HAIL SIZE...0.25 IN
MAX WIND GUST...40 MPH

JPT