Special Weather Statement, NWS Greenville-Spartanburg, SC

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
753 PM EDT Fri Aug 20 2021

.SYNOPSIS...
Scattered showers and thunderstorms chances will continue into the
early evening hours. Subsidence aloft associated with a ridge of
high pressure over the south-central CONUS will slowly build
eastward into the Carolinas and Georgia leading to drier conditions
this weekend and early next week. The upper-level pattern will
remain relatively unchanged during this time. Isolated showers and
thunderstorms will remain possible this weekend into early next week.

&&

.NEAR TERM /THROUGH SATURDAY/...
As of 745 PM EDT Friday: Convection has largely failed to develop
apart from a few rogue cells over the foothills.  Continued
convective initiation is unlikely at this point as temperatures
cool down for the evening, but substantial instability remains,
so the few cells that are underway may persist a tad longer.

Overnight, as dry air continues to filter in from the north, the
upper levels should become dry enough to support at least patchy
fog development.  Although a few of the models are predicting
fog outside the mountains, the odds seem reduced for much of a
reduction in visibility given that so little rain has fallen and
the PBL will be a good amount drier than anticipated.  Indeed,
it may be primarily our mountain sites at risk of fog in the early
morning hours.

Saturday, as a deepening upper low begins to pivot east of the
CWA, heights should hold stable or even begin to rise slightly
by afternoon; thus, synoptic forcing will be weak/nonexistent.
This combined with dry mid/upper levels should severely hinder
convective initiation tomorrow, and so we should see even more
anemic thunder activity Saturday afternoon than we have today.
A few pulse storms may pop up, along with isolated to widely
scattered showers, but for the most part, below-climo convective
activity is in the works.

&&

.SHORT TERM /SATURDAY NIGHT THROUGH SUNDAY NIGHT/...
As of 2:15 PM EDT Friday: Throughout the short term forecast period,
a ridge of high pressure will build across the south-central CONUS
while a closed low over the Mid-Atlantic interacts with Tropical
Storm Henri out in the western Atlantic. The ridge of high pressure
will gradually build eastward into the CWA this weekend into early
next week. As a result, the closed low will be forced northeast of
the Carolinas, gradually tracking towards New England through early
next week. This ridge of high pressure will lead near normal PWATs
and mainly NW'ly flow this weekend into Monday allowing for much
drier conditions. With no real synoptic forcing in place, daytime
heating will be the driver of diurnal showers and thunderstorms.
However, with limited moisture available across the forecast area,
only isolated showers and thunderstorms are expected throughout the
short term so capped PoPs to a slight chance to chance. High temps
should be roughly 4 to 8 degrees above Climo Sunday and Monday.

&&

.LONG TERM /MONDAY THROUGH FRIDAY/...
As of 230 PM EDT Friday: The eastern periphery of the ridge remains
over the Carolinas and Georgia at the beginning of the extended
forecast period, but retreats back west middle of next week. This
will allow the Bermuda high in the Atlantic to extend over the
southeast CONUS. So the overall synoptic pattern middle of next week
will have the Carolinas and northeast Georgia sandwiched between two
high pressure systems. This will lead to increased moisture and the
continuation of above climo high temps. PWAT values will increase
Tuesday ranging from 1.70 to 2.0 inches. These values are expected
to linger over the CWA through the end of the forecast period.
Tuesday into Wednesday shower and thunderstorm chances increase due
to a surface trough draped over the central Carolinas. This sfc
trough should remain over the Carolinas throughout the extended.
Both the GFS and ECMWF show the two ridges of high pressure working
together to bring a tropical wave into the Carolinas Thursday into
Friday. This would further increase shower and thunderstorm chances
middle to end of the workweek. Confidence on the track of this
tropical wave remains fairly low as this occurs towards the end of
the extended forecast.

&&

.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
At KCLT and elsehwere: Convection has failed to develop this
afternoon at any of the TAF sites, and with conditions beginning
to look less and less conducive to thunder, have removed TEMPOs
for TSRA from the 00Z TAFs and left only VCSH for a few hours
at KCLT and some of the other Piedmont sites. Should see
scattered to broken sky cover overnight, with a lingering chance
of some morning fog at mountain sites. Given that none of our
sites have received rain, chances seem somewhat reduced, but the
signal is still present in the MOS products, and mid levels are
trending dryer, so have kept mention of some MVFR VSBYs at KHKY
dropping to IFR at KAVL. Otherwise, a chance for isolated to
widely scattered convection tomorrow, with initiation time
delayed and intensity hindered by dry air aloft. For now, have
only thrown in PROB30s for SHRA at each site mid-afternoon.

Outlook: A typical, diurnal summertime convective pattern is
expected to prevail the rest of the weekend and into early next
week, with coverage scattered at best. Mountain valley fog will
be possible each morning, especially for sites that received rain
the previous afternoon.

&&

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

&&

SYNOPSIS...AP
NEAR TERM...MPR
SHORT TERM...AP
LONG TERM...AP
AVIATION...MPR

Hazardous Weather Outlook
National Weather Service Greenville-Spartanburg SC
451 PM EDT Fri Aug 20 2021

GAZ010-017-018-026-028-029-NCZ033-035>037-048>053-056>059-062>065-
068>072-082-501>510-SCZ001>014-019-212100-
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-
451 PM EDT Fri Aug 20 2021

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

.DAY ONE...Tonight.

Isolated to scattered showers and thunderstorms are expected late this
afternoon and evening. A few of these storms could become strong to severe.
The main threats from any thunderstorm will be cloud-to-ground lightning,
damaging winds, and localized flash flooding.

.DAYS TWO THROUGH SEVEN...Saturday through Thursday.

No hazardous weather is expected at this time.

.SPOTTER INFORMATION STATEMENT...

None.

JPT

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
528 PM EDT FRI AUG 20 2021

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0457 PM     TSTM WND DMG     TOCCOA                  34.58N 83.32W
08/20/2021                   STEPHENS           GA   TRAINED SPOTTER

            TREES DOWN OFF SMITH RD IN TOCCOA.

&&

JPT

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
528 PM EDT Fri Aug 20 2021

GAZ018-026-028-029-202200-
Elbert GA-Hart GA-Franklin GA-Stephens GA-
528 PM EDT Fri Aug 20 2021

...A strong thunderstorm will impact portions of Franklin,
southeastern Stephens, northwestern Elbert and western Hart Counties
through 600 PM EDT...

At 528 PM EDT, Doppler radar was tracking a strong thunderstorm 5
miles north of Carnesville, or near Martin, moving southeast at 25
mph.

HAZARD...Wind gusts up to 50 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...
Carnesville, Hartwell, Royston, Lavonia, Gumlog, Bowman, Canon,
Franklin Springs, Bowersville and Martin.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

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

Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

&&

LAT...LON 3417 8310 3419 8309 3420 8309 3423 8308
      3426 8311 3427 8311 3424 8317 3425 8324
      3441 8339 3443 8338 3446 8340 3457 8319
      3430 8287 3416 8310
TIME...MOT...LOC 2128Z 324DEG 22KT 3445 8320

MAX HAIL SIZE...0.25 IN
MAX WIND GUST...50 MPH

RWH

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
558 PM EDT Fri Aug 20 2021

GAZ026-028-029-202230-
Elbert GA-Hart GA-Franklin GA-
558 PM EDT Fri Aug 20 2021

...A strong thunderstorm will impact portions of southeastern
Franklin, northwestern Elbert and southwestern Hart Counties through
630 PM EDT...

At 558 PM EDT, Doppler radar was tracking a strong thunderstorm 5
miles southeast of Carnesville, or over Victoria Bryant State Park,
moving southeast at 25 mph.

HAZARD...Wind gusts up to 50 mph.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects.

Locations impacted include...
Carnesville, Royston, Bowman, Canon, Franklin Springs, Bowersville,
Victoria Bryant State Park, Dewy Rose and Vanna.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

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

Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

&&

LAT...LON 3410 8304 3411 8303 3412 8305 3415 8306
      3417 8310 3423 8308 3426 8311 3427 8311
      3424 8317 3425 8320 3424 8325 3425 8327
      3434 8330 3441 8311 3412 8289 3408 8301
TIME...MOT...LOC 2158Z 336DEG 20KT 3431 8317

MAX HAIL SIZE...0.00 IN
MAX WIND GUST...50 MPH

RWH

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
721 PM EDT Fri Aug 20 2021

NCZ056-068-069-504-202345-
Cleveland NC-Lincoln NC-Greater Burke NC-Catawba NC-
721 PM EDT Fri Aug 20 2021

...A strong thunderstorm will impact portions of southwestern
Catawba, western Lincoln, northwestern Cleveland and southeastern
Burke Counties through 745 PM EDT...

At 721 PM EDT, Doppler radar was tracking a strong thunderstorm 13
miles southeast of Morganton, or 5 miles east of South Mountains
State Park, moving south at 10 mph.

HAZARD...Winds in excess of 40 mph.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects.

Locations impacted include...
Belwood, Lawndale, Fallston, Polkville, Casar, South Mountains State
Park, Pleasant Grove, Cooksville and Vale.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

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

Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

&&

LAT...LON 3542 8136 3542 8145 3541 8145 3539 8169
      3564 8168 3566 8146
TIME...MOT...LOC 2321Z 352DEG 9KT 3558 8156

MAX HAIL SIZE...0.00 IN
MAX WIND GUST...40 MPH

RWH

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
744 PM EDT Fri Aug 20 2021

NCZ068-069-210015-
Cleveland NC-Lincoln NC-
744 PM EDT Fri Aug 20 2021

...A strong thunderstorm will impact portions of western Lincoln and
central Cleveland Counties through 815 PM EDT...

At 744 PM EDT, Doppler radar was tracking a strong thunderstorm 15
miles north of Shelby, or near Casar, moving south at 10 mph.

HAZARD...Winds in excess of 40 mph.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects.

Locations impacted include...
Belwood, Lawndale, Fallston, Polkville, Lattimore, Waco, Casar and
Kingstown.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

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

Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

&&

LAT...LON 3557 8158 3556 8157 3557 8153 3557 8145
      3542 8140 3542 8145 3536 8141 3534 8137
      3531 8170 3557 8168 3556 8164 3557 8160
TIME...MOT...LOC 2344Z 353DEG 10KT 3551 8156

MAX HAIL SIZE...0.00 IN
MAX WIND GUST...40 MPH

RWH

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
841 PM EDT Fri Aug 20 2021

NCZ504-506-210115-
Greater Burke NC-Eastern McDowell NC-
841 PM EDT Fri Aug 20 2021

...A strong thunderstorm will impact portions of southeastern
McDowell and southwestern Burke Counties through 915 PM EDT...

At 841 PM EDT, Doppler radar was tracking a strong thunderstorm 7
miles east of Marion, or near Lake James State Park, moving south 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...
Marion, Morganton, Glen Alpine, Lake James State Park, Lake James,
South Mountains State Park, Nebo, Glenwood, Fero and Dysartsville.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

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

Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

&&

LAT...LON 3557 8167 3558 8169 3558 8170 3561 8172
      3560 8174 3561 8176 3559 8177 3559 8179
      3558 8180 3558 8182 3554 8185 3552 8197
      3554 8199 3573 8200 3580 8189 3583 8179
TIME...MOT...LOC 0041Z 348DEG 11KT 3571 8188

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

RWH