Special Weather Statement, NWS Greenville-Spartanburg, SC

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
1051 AM EDT Sat Aug 7 2021

.SYNOPSIS...
A moist stationary front will persist across the central Carolinas
today, bringing a threat of locally heavy rainfall. An upper level
disturbance entering the region will help push the front off to
the east, but also enhance the development of thunderstorms over
parts of the area this afternoon. Drier high pressure builds into
the area Sunday, returning typical summertime weather across the
region through the middle of next week.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 1038 AM: Morning satellite imagery shows the mid-level
moisture gradient progressing slowly east across the fcst area,
while sfc analysis suggests the frontal zone has already cleared
the eastern zones. As such, we have only a few patches of very
light rain/sprinkles over the srn part of metro Charlotte, which
should move clear of the fcst area by noon, and thus a lull in the
action is already underway. Precip chances will be curtailed in
those areas. Meanwhile, a slow moving thunderstorm persists on the
TN side of the Smokies, but shower activity was moving over the NC
side. This activity was developing underneath the upper trof axis
where a trailing short wave was located... perhaps an indicator of
the better chances for redevelopment early this afternoon over the
mtns. Some partial clearing has occurred over the wrn half of the
fcst area, which should allow for destabilization this afternoon. An
increase in shower/tstm coverage still looks like a decent bet.

Otherwise, still expecting likely/numerous coverage over the
mountains which will propagate into the foothills; continued
downsloping may not be especially supportive of carrying the
activity much further than that, but given the strength of the
shortwave it seems worthy of a mentionable PoP in all locations
this afternoon. Chances will diminish this evening diurnally and as
the shortwave axis passes east. PWATs with the afternoon activity
won't be what they were this morning, but storm motion vectors
are fairly short and we can't rule out some additional excessive
rainfall. Shear doesn't look sufficient for anything but loosely
organized clusters, so severe threat looks low.

Eventually mostly sunny skies in the central CWA in conjunction
with the downslope there should allow max temps almost back
to normal. Elsewhere, expect max temps several degrees below
normal. Dewpoints however will be back in the muggy upper 60s to
low 70s over much of the area this afternoon, so that will be a
change. Clearing skies behind the shortwave tonight will allow
temps near or slightly below normal. The mountain valleys appear
to be at risk of radiation fog and possibly a few areas of the
Piedmont, per dense fog signal depicted in NAMNest.

&&

.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
As of 300 AM EDT Saturday...Upper ridging will take hold of the
region Sunday thru Monday, and the height rises will result in
warmer mid-level temps due to subsidence. Forecast soundings
look fairly capped across the Piedmont Sunday, with some skinny
CAPE in the high terrain. So only isolated showers and perhaps
a tstm or two is all that can be expected across the mountains
and adjacent Foothills. Low-level flow will back from westerly
to southwesterly Monday, transporting more moisture into the
region. So there should be a little more instability Monday aftn
for convection. Will feature generally 15-30 PoPs across the area,
favoring the mountains. Shear will be weak, so pulse storm mode
is expected, but severe threat looks low given the influence of
the ridge aloft. Highs will be near normal Sunday and a deg or
two warmer Monday.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
As of 315 AM EDT Saturday...The models still in above average
agreement in the medium range with the overall pattern. The
subtropical ridge will persist across the Southeast, with some
troughing trying to erode the northern part of the ridge across
the northern tier of the US. Meanwhile at the sfc, a Bermuda high
will pump in deeper moisture into the region, as a slow-moving front
sags south into the Ohio Valley. A gradual increase in diurnal PoPs
is expected with temps continuing to be slightly above normal.
Depending on how the front stalls out, we could see an increased
threat of excessive rainfall toward the end of the period (late
next week). Overall, severe threat will remain low, but an isolated
pulse/microburst threat will likely exist each day.

&&

.AVIATION /15Z SATURDAY THROUGH WEDNESDAY/...
In general: Nearly stalled frontal boundary across the Piedmont,
east of KGSP/KHKY and west of KCLT at 12z, will drift SE later
this morning as a weak frontal wave exits the region. Widespread
restrictions will persist near the front this morning along with a
few SHRA; otherwise mostly VFR to start. A fairly strong shortwave
trough sits just west of the Appalachians. This shortwave will
enhance diurnal destabilization/convective initiation, warranting
afternoon precip mention. Precip more likely than not near the
Blue Ridge Escarpment (and KAVL/KGSP/KGMU/KHKY). Winds will be
tricky this period with complex pressure pattern evolving. Mainly
northerly this morning; mixing to W/SW will be possible this
afternoon before they set up again NW in the wake of the shortwave.

At KCLT: IFR will predominate at KCLT until the front pushes past,
and a brief heavy downpour will be possible at the beginning of
the period. Afternoon precip chance warrants a conditional group
but cannot use PROB30 due to policy, so have a second TEMPO then.

Outlook: Shower activity should remain mostly over the mtns on
Sunday, but will be more diurnal in nature over the entire fcst
area 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...

            15-21Z        21-03Z        03-09Z        09-12Z
KCLT       Med   75%     High 100%     High 100%     High  91%
KGSP       High 100%     High 100%     High 100%     High  91%
KAVL       High  95%     High 100%     High  91%     Low   53%
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 are available at
the following link:

www.weather.gov/gsp/aviation

&&

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

&&

SYNOPSIS...Wimberley
NEAR TERM...PM/Wimberley
SHORT TERM...ARK
LONG TERM...ARK
AVIATION...Wimberley

Hazardous Weather Outlook
National Weather Service Greenville-Spartanburg SC
514 AM EDT Sat Aug 7 2021

GAZ018-026-028-029-NCZ035>037-056-057-068>072-082-SCZ004>014-019-
080915-
Stephens-Franklin-Hart-Elbert-Alexander-Iredell-Davie-Catawba-Rowan-
Cleveland-Lincoln-Gaston-Mecklenburg-Cabarrus-Union NC-
Greater Oconee-Greater Pickens-Greater Greenville-Spartanburg-
Cherokee-York-Anderson-Abbeville-Laurens-Union SC-Chester-Greenwood-
514 AM EDT Sat Aug 7 2021

This Hazardous Weather Outlook is for the Piedmont of North and South
Carolina, plus a portion of northeast Georgia.

.DAY ONE...Today and tonight.

Isolated to scattered showers will occur this morning near a weak
area of low pressure over the region. Ample moisture will allow
these showers to produce locally heavy rainfall. The low will move
out of the area later today. Scattered thunderstorms also will
develop, mainly in the afternoon. Cloud-to-ground lightning will be
possible with any of these storms.

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

No hazardous weather is expected at this time.

.SPOTTER INFORMATION STATEMENT...

None.

GAZ010-017-NCZ033-048>053-058-059-062>065-501>510-SCZ001>003-080915-
Rabun-Habersham-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-
514 AM EDT Sat Aug 7 2021

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

.DAY ONE...Today and tonight.

Scattered thunderstorms will develop today, with the greatest
coverage being in the afternoon. Any of these storms will be capable
of cloud-to-ground lightning and locally heavy rainfall.

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

No hazardous weather is expected at this time.

.SPOTTER INFORMATION STATEMENT...

None.

Wimberley

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
1235 PM EDT Sat Aug 7 2021

NCZ052-071700-
Haywood NC-
1235 PM EDT Sat Aug 7 2021

...A strong thunderstorm will impact portions of central Haywood
County through 100 PM EDT...

At 1235 PM EDT, Doppler radar was tracking a strong thunderstorm 10
miles northwest of Waynesville, or near Smoky Mountains-Cataloochee,
moving east 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...
Waynesville, Lake Junaluska, Clyde, Maggie Valley, Smoky
Mountains-Cataloochee, B.R. Parkway-Smoky Mountains To Balsam Gap,
Smoky Mountains-Balsam Mountain, Smoky Mountains-Big Creek, Cove
Creek and Fines Creek.

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 3570 8290 3568 8290 3567 8288 3564 8287
      3563 8285 3543 8290 3552 8318 3554 8317
      3555 8316 3558 8317 3559 8318 3571 8315
TIME...MOT...LOC 1635Z 281DEG 10KT 3561 8309

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

KRENTZ

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

GAZ010-SCZ001-071730-
Rabun GA-Oconee Mountains SC-
104 PM EDT Sat Aug 7 2021

...A strong thunderstorm will impact portions of northeastern Rabun
and north central Oconee Counties through 130 PM EDT...

At 104 PM EDT, Doppler radar was tracking a strong thunderstorm 14
miles north of Walhalla, or 6 miles southeast of Highlands, moving
east 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...
Walhalla, Salem, Devils Fork State Park, Oconee State Park, Lake
Jocassee, Mountain Rest, Bad Creek and Pine Mountain.

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 3500 8324 3500 8311 3502 8302 3503 8301
      3501 8293 3499 8294 3497 8293 3477 8305
      3486 8323
TIME...MOT...LOC 1704Z 267DEG 9KT 3496 8315

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

KRENTZ

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

NCZ052-053-071800-
Buncombe NC-Haywood NC-
125 PM EDT Sat Aug 7 2021

...A strong thunderstorm will impact portions of east central Haywood
and west central Buncombe Counties through 200 PM EDT...

At 125 PM EDT, Doppler radar was tracking a strong thunderstorm 13
miles west of Downtown Asheville, or 5 miles west of Leicester,
moving east 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...
Leicester, Enka, Candler and Canto.

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 3552 8263 3557 8288 3569 8287 3570 8284
      3569 8281 3570 8279 3570 8277 3571 8275
      3573 8262
TIME...MOT...LOC 1725Z 273DEG 14KT 3562 8279

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

KRENTZ

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

SCZ001-002-004-005-071815-
Pickens Mountains SC-Greater Pickens SC-Greater Oconee SC-
Oconee Mountains SC-
133 PM EDT Sat Aug 7 2021

...A strong thunderstorm will impact portions of southwestern Pickens
and central Oconee Counties through 215 PM EDT...

At 132 PM EDT, Doppler radar was tracking a strong thunderstorm near
Walhalla, moving east 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...
Seneca, Walhalla, Westminster, Six Mile, Salem, Lake Keowee, Oconee
State Park, Mountain Rest, Oakway and Townville.

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 3471 8328 3491 8318 3490 8311 3488 8278
      3459 8288 3455 8292
TIME...MOT...LOC 1732Z 285DEG 11KT 3480 8309

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

JPT