Special Weather Statement, NWS Greenville-Spartanburg, SC

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
341 AM EDT Wed Sep 8 2021

.SYNOPSIS...
A cold front is expected to cross our area from the northwest later
today into early Thursday and bring more widespread showers and
thunderstorms to the region. Drying high pressure will spread back
over the region in the front's wake and linger through the weekend
and into the first half of next week, while summertime conditions
make a return to the area as well.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 325 AM EDT Wednesday: Over the past hour or so, we have
seen a cluster of cells come together over Stephens, Franklin,
and Oconee Counties and produce a large cell that appears to
have come close to severe criteria based on RADAR signatures.
Otherwise, the rest of the CWA remains mostly quiet. Additional
isolated to sct convection will likely linger for a few more
hours, especially over the SLY upslope prone areas and far NE
Georgia. Stronger storms should be limited by the diminishing
instability, and heavier QPF should be limited by moderate storm
movement. Abundant cloud cover will help keep low temps about 3
to 5 degrees above normal over most areas. Mtn valley fog will
likely develop thru the morning hours with any breaks in the
clouds.

Otherwise, once any lingering morning showers fizzle out and cloud
cover thins a bit, guidance suggests robust instability will develop
during the afternoon, around the same time that the frontal zone
associated with upstream height falls is expected to move into the
fcst area. I kept likely PoPs across most of the Piedmont and the
SE half of our Upstate zones, where less morning clouds/showers are
anticipated early on. Solid chance PoPs are advertised elsewhere.
Deep-lyr shear still looks minimal wrt its potential to organized
storms, however, 0-3 km shear in the 15-25 kt range will likely be
enough to support clustering of cells along cold pools. Microbursts
will be possible in association with any clusters as well as with
single cell pulse storms. If the fcst CAPE profiles pan out, we
could see some larger hail from a few storms, especially over the
NC Piedmont. High temps are expected to top out a few degrees above
climatology today.

&&

.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
As of 115 AM EDT Wednesday: The frontal zone is expected to be
in the far eastern CFWA during the beginning portions of the
short-term. Leftover moisture along the boundary may warrant an
early morning shower or thunderstorm along and east of the I-77
corridor, but dry air advection behind the fropa will lead to
much drier conditions during the day Thursday as high pressure
slowly builds in from the west. The upper trough over the Great
Lakes and OH Valley will help push the frontal boundary eastward
as the axis of the upper trough slips past the CFWA Thursday
evening. The sfc pressure gradient tightens up slightly Thursday
into Thursday night and could lead to low-end breezy conditions,
especially in the High Country, but any wind gusts should subside
by Friday morning as the center of the sfc high sets up shop
over the central Appalachians. Mostly sunny and dry conditions will
prevail through Friday as a result. Anomalously lower thicknesses
will keep temperatures in check with near-normal values expected
through the forecast period for highs and a category below normal
for lows as good radiational cooling processes will be in store for
both Thursday and Friday nights.

&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
As of 215 AM EDT Wednesday: Sfc high will hold steady over the
Mid-Atlantic Saturday, while sliding offshore by Sunday. This
will allow for a return flow to enter back into the CFWA, along
with rising heights from a deepening upper ridge over the central
CONUS. A warming and more humid trend will prevail in this set up
through the period, but the additional subsidence aloft will help
cap any shower and thunderstorm development through the early part
of next week. The next frontal boundary is shown encroaching the
area by the middle part of next week, according to the GFS. Model
guidance keep this away from the CFWA through the day seven, so
most of the extended will remain dry. There are some differences in
the global models. The GFS sags the frontal boundary with height
falls towards the area by next Wednesday and Thursday, while the
ECMWF develops a sub-tropical ridge over the Mid-Atlantic region
and keeps any type of frontal zone far north and west. Either way,
the CFWA will remain mostly dry while temperatures uptick slightly
each day as we introduce another round of summertime conditions
during the medium range.

&&

.AVIATION /08Z WEDNESDAY THROUGH SUNDAY/...
At KCLT and Elsewhere: We've been seeing some robust convective
cells develop over our southern Upstate zones, and some activity
coming up from the SW and moving into our NE Georgia zones. Sct
convection will likely continue through the overnight hours,
especially over the SLY upslope prone areas. Additional VCSH
and/or TEMPOs for SHRA and/or TSRA may be needed through the
overnight and into the morning, mainly across the Upstate sites
and near KAVL, with KAND already carrying a TEMPO for TSRA for
the first couple hours of the period from 06 to 08z. Signals
remain mixed wrt the potential for early morning fog/low stratus,
but any breaks in the clouds will likely permit LIFR conditions
to develop quickly over the mtn valleys and around KAVL. Winds
will be mainly light and SLY to SWLY for the bulk of the period,
but with an uptick in speed to about 10kt with some low-end gusts
this afternoon. I kept the PROB30s for convective chances for
the afternoon/evening hours with the approach of the front from
the NW. Most of the precip should be moving east of our fcst area
as the taf period ends at 06z.

Outlook: Generally fair weather and high pressure is expected
on Thursday in the wake of the frontal passage. The fair wx will
likely persist thru the weekend and into early next week. Mtn
valley fog and low stratus will remain possible each morning.

&&

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

&&

SYNOPSIS...CAC
NEAR TERM...JPT
SHORT TERM...CAC
LONG TERM...CAC
AVIATION...JPT

Hazardous Weather Outlook
National Weather Service Greenville-Spartanburg SC
1038 PM EDT Tue Sep 7 2021

GAZ010-017-018-026-028-029-NCZ048-051>053-058-059-062>065-068>072-
082-507>510-SCZ001>014-019-090245-
Rabun-Habersham-Stephens-Franklin-Hart-Elbert-Madison-Swain-Haywood-
Buncombe-Graham-Northern Jackson-Macon-Southern Jackson-Transylvania-
Henderson-Cleveland-Lincoln-Gaston-Mecklenburg-Cabarrus-Union NC-
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-
1038 PM EDT Tue Sep 7 2021

This Hazardous Weather Outlook is for northeast Georgia, the
Piedmont, southern foothills, and central and southern mountains of
western North Carolina, as well as Upstate South Carolina.

.DAY ONE...Tonight.

Isolated to scattered thunderstorms will redevelop from the southwest
through the overnight hours. The main impacts with any thunderstorms
that form will be briefly gusty winds, locally heavy rainfall, and
cloud-to-ground lightning strikes.

.DAYS TWO THROUGH SEVEN...Wednesday through Monday.

No hazardous weather is expected at this time.

.SPOTTER INFORMATION STATEMENT...

None.

NCZ033-035>037-049-050-056-057-501>506-090245-
Avery-Alexander-Iredell-Davie-Yancey-Mitchell-Catawba-Rowan-
Caldwell Mountains-Greater Caldwell-Burke Mountains-Greater Burke-
McDowell Mountains-Eastern McDowell-
1038 PM EDT Tue Sep 7 2021

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

.DAY ONE...Tonight.

No hazardous weather is expected at this time.

.DAYS TWO THROUGH SEVEN...Wednesday through Monday.

No hazardous weather is expected at this time.

.SPOTTER INFORMATION STATEMENT...

None.

HG

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
1215 AM EDT Wed Sep 8 2021

SCZ011-012-019-080500-
Laurens SC-Abbeville SC-Greenwood SC-
1215 AM EDT Wed Sep 8 2021

...A THUNDERSTORM WITH INTENSE LIGHTNING WILL IMPACT SOUTHWESTERN
LAURENS...EAST CENTRAL ABBEVILLE AND NORTHERN GREENWOOD COUNTIES
UNTIL 100 AM EDT...

At 1215 AM EDT, Doppler radar was tracking a thunderstorm with
intense lightning 5 miles west of Greenwood, moving northeast at 20
mph.

Locations to be impacted include...
Greenwood, Abbeville, Ware Shoals, Ninety Six, Cross Hill, Cokesbury,
Waterloo, Hodges, Lake Greenwood and Greenwood State Park.

In addition to intense lightning, very heavy rainfall rates up to 2
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.

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 3417 8240 3450 8224 3429 8190 3424 8191
      3420 8194 3406 8221
TIME...MOT...LOC 0415Z 218DEG 16KT 3420 8225

CAC

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
100 AM EDT Wed Sep 8 2021

GAZ028-SCZ010-080530-
Hart GA-Anderson SC-
100 AM EDT Wed Sep 8 2021

...A THUNDERSTORM WITH INTENSE LIGHTNING WILL IMPACT NORTHEASTERN
HART AND CENTRAL ANDERSON COUNTIES UNTIL 130 AM EDT...

At 100 AM EDT, Doppler radar was tracking a thunderstorm with intense
lightning 8 miles east of Hartwell, or 5 miles west of Starr, moving
northeast at 10 mph.

Locations to be impacted include...
Anderson, Homeland Park, Northlake, Starr, Anderson Airport, Lake
Hartwell, Iva, Reed Creek, Sandy Springs and Broadway Lake.

In addition to intense lightning, very heavy rainfall rates up to 2
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.

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 3427 8275 3429 8277 3428 8279 3432 8292
      3462 8284 3464 8283 3447 8249 3426 8272
TIME...MOT...LOC 0500Z 206DEG 10KT 3438 8279

CAC

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
118 AM EDT Wed Sep 8 2021

GAZ028-SCZ010-080545-
Hart GA-Anderson SC-
118 AM EDT Wed Sep 8 2021

...A THUNDERSTORM WITH INTENSE LIGHTNING WILL IMPACT CENTRAL HART AND
SOUTHWESTERN ANDERSON COUNTIES UNTIL 145 AM EDT...

At 118 AM EDT, Doppler radar was tracking a thunderstorm with intense
lightning near Hartwell, moving northeast at 5 mph.

Locations to be impacted include...
Hartwell, Reed Creek, Lake Hartwell, Homeland Park and Sadlers Creek
State Park.

In addition to intense lightning, very heavy rainfall rates up to 2
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.

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 3433 8303 3449 8298 3455 8292 3445 8266
      3427 8287
TIME...MOT...LOC 0518Z 223DEG 6KT 3434 8293

CAC

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
227 AM EDT Wed Sep 8 2021

GAZ010-017-018-026-SCZ001-004-080700-
Franklin GA-Rabun GA-Stephens GA-Habersham GA-Greater Oconee SC-
Oconee Mountains SC-
227 AM EDT Wed Sep 8 2021

...A THUNDERSTORM WITH INTENSE LIGHTNING WILL IMPACT NORTHEASTERN
FRANKLIN...STEPHENS...EASTERN HABERSHAM...CENTRAL RABUN AND OCONEE
COUNTIES UNTIL 300 AM EDT...

At 227 AM EDT, Doppler radar was tracking a thunderstorm with intense
lightning 8 miles east of Toccoa, or 6 miles southwest of
Westminster, moving northeast at 25 mph.

Locations to be impacted include...
Toccoa, Seneca, Walhalla, Clayton, Westminster, Gumlog, Martin,
Avalon, Tallulah Falls and Lake Rabun.

In addition to intense lightning, very heavy rainfall rates up to 2
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.

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 3445 8309 3449 8344 3474 8352 3497 8333
      3479 8289
TIME...MOT...LOC 0627Z 207DEG 21KT 3462 8319

CAC

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
309 AM EDT Wed Sep 8 2021

GAZ010-018-026-028-SCZ001-004-080745-
Hart GA-Franklin GA-Rabun GA-Stephens GA-Greater Oconee SC-
Oconee Mountains SC-
309 AM EDT Wed Sep 8 2021

...THUNDERSTORMS WITH INTENSE LIGHTNING WILL IMPACT FRANKLIN...
STEPHENS...EASTERN RABUN...NORTHWESTERN HART AND CENTRAL OCONEE
COUNTIES UNTIL 345 AM EDT...

At 309 AM EDT, Doppler radar indicated thunderstorms with intense
lightning along a line extending from 6 miles east of Clayton to 5
miles west of Carnesville, and moving east at 15 mph.

Locations to be impacted include...
Toccoa, Walhalla, Carnesville, Westminster, Lavonia, Gumlog, Canon,
Bowersville, Martin and Avalon.

In addition to intense lightning, very heavy rainfall rates up to 2
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.

Frequent lightning is occurring with these storms. 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 storms approach.

&&

LAT...LON 3433 8339 3439 8338 3444 8339 3468 8336
      3469 8334 3470 8335 3472 8335 3492 8333
      3500 8301 3432 8303 3428 8335
TIME...MOT...LOC 0709Z 250DEG 11KT 3488 8329 3437 8333

CAC

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
346 AM EDT Wed Sep 8 2021

GAZ018-026-028-029-SCZ001-004-005-010-080815-
Elbert GA-Hart GA-Franklin GA-Stephens GA-Greater Pickens SC-
Greater Oconee SC-Anderson SC-Oconee Mountains SC-
346 AM EDT Wed Sep 8 2021

...THUNDERSTORMS WITH INTENSE LIGHTNING WILL IMPACT FRANKLIN...
EASTERN STEPHENS...NORTHWESTERN ELBERT...HART...SOUTHWESTERN
ANDERSON...SOUTHWESTERN PICKENS AND SOUTHERN OCONEE COUNTIES UNTIL
415 AM EDT...

At 346 AM EDT, Doppler radar indicated thunderstorms with intense
lightning along a line extending from 10 miles north of Toccoa to
near Carnesville, and moving northeast at 10 mph.

Locations to be impacted include...
Clemson, Seneca, Hartwell, Walhalla, Carnesville, Central, Pendleton,
Royston, Westminster and Reed Creek.

In addition to intense lightning, very heavy rainfall rates up to 2
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.

Frequent lightning is occurring with these storms. 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 storms approach.

&&

LAT...LON 3422 8308 3427 8312 3425 8316 3429 8327
      3472 8328 3482 8290 3481 8290 3483 8285
      3485 8278 3425 8276 3420 8304
TIME...MOT...LOC 0746Z 217DEG 7KT 3472 8326 3434 8323

CAC