Severe Thunderstorm Warning 131, NWS Greenville-Spartanburg, SC

523 
WWUS52 KGSP 141926
SVSGSP

Severe Weather Statement
National Weather Service Greenville-Spartanburg SC
326 PM EDT Sat Aug 14 2021

NCC035-109-141934-
/O.CAN.KGSP.SV.W.0131.000000T0000Z-210814T1945Z/
Catawba NC-Lincoln NC-
326 PM EDT Sat Aug 14 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN CATAWBA AND
CENTRAL LINCOLN COUNTIES IS CANCELLED...
                
The storm which prompted the warning has weakened below severe
limits, and no longer poses an immediate threat to life or property.
Therefore, the warning has been cancelled. However gusty winds and 
heavy rain are still possible from Lincolnton to Claremont through 
400 PM.

LAT...LON 3543 8116 3548 8137 3577 8128 3562 8093
TIME...MOT...LOC 1918Z 194DEG 8KT 3560 8123 

$$

LANE

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
252 PM EDT Sat Aug 14 2021

.SYNOPSIS...
A cold front arriving from the north will stall out across our
region on Sunday bringing cooler temperatures.  Abundant tropical
moisture will be across our area through much of the week as we can
expect numerous afternoon showers and thunderstorms with occasional
heavy rainfall.

&&

.NEAR TERM /THROUGH SUNDAY/...
As of 230 pm: Strong instability (sbCAPE > 3000 J/kg across much of
the area) has resulted in scattered convection developing this
afternoon, with the best coverage actually observed in the most
unstable air (sbCAPE 3500-4500 J/kg) along and southeast of the I-85
corridor. Meanwhile, the mountains are relatively quiet...almost too
quiet...as coverage there has been widely scattered at most thus far
this afternoon. Nevertheless, cumulus congestus abounds along the
ridge tops, and we still expect at least solid scattered coverage to
develop there by the end of the afternoon. Outflows from this
activity may then provide another round of scattered activity across
the Piedmont this evening. The main concern going forward will be
locally heavy and perhaps isolated excessive rainfall, as
slow-moving and/or backbuilding cells could result in rainfall
amounts as high as 3" in an hour. Otherwise, the strong instability
and downdraft CAPE of around 1000 J/kg will allow for a few
strong-to-severe microbursts from pulse updrafts.

In light of the good coverage this afternoon, which should put down
a decent amount of rain-cooled air, we do not expect the eruption of
deep convection that was observed late Fri evening into the early
part of the overnight. However, with weak surface boundary expected
to sag across the area and interact with a muggy and weakly unstable
air mass, isolated to widely scattered showers and a few TS will
remain possible through the overnight.

Sunday should see even better coverage of mainly afternoon showers
and storms as the weak boundary roughly bisects the forecast area,
moisture increases (PWATs of around 2" across the Piedmont by the
end of the day) and the flow aloft becomes even less anticyclonic,
with perhaps even some weak disturbances lifting toward the area
from the Gulf Coast. Likely to categorical PoPs are advertised in
all locations by the end of the day. In terms of convective threats,
widespread early day cloud cover is expected to result in a bit of a
cooling trend. In fact, max temps are forecast to top out a couple
of degrees shy of normal, or a solid 5-7 degrees cooler than they've
been in recent days. As such, instability will be quite a bit weaker
Sunday afternoon, and the severe storm threat therefore a bit lower
(albeit non-zero). The larger concern will be a continued threat for
locally excessive rainfall.

&&

.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
As of 100 PM EDT Saturday: Very soggy pattern will be in store
during the short-term period. The sub-tropical high off the Atlantic
will transport tropical moisture into the CFWA with the help of a
weak upper low over the eastern Gulf Coast, which will allow for
PWAT values to top off at ~150% above normal for this time of the
year. At the same time, a frontal boundary will be draped across
the CFWA and is expected to stall during the early part of next
week. The remnants of Fred will only add to the tropical airmass and
thus, multiple days of heavy rainfall and a continued flood threat
will be possible across the CFWA. With the stalled front providing
a focus for shower and thunderstorm initiation, expect for daily
development of diurnal convection with the threat of this activity
lingering into the overnight hours each night. To cap the discussion
off, a broad area of high pressure is expected to set up shop over
New England and will provide a wedge-like pattern over the region
and will bring an uptick in PoPs due to upglide/upslope enhancement.

While analyzing at a few model soundings across the CFWA, a couple
of atmospheric processes stand out and will help increase the
overall flood threat. A deeper warm cloud layer, skinnier CAPE
profiles, and deep layer saturation within the atmospheric column
will likely kick off very heavy rain rates in any convection that
develops. With very weak shear parameters, expect slow motion cells
which in turn, will dump buckets of rain over various locations
within the CFWA, especially in areas that are near the frontal
boundary where training cells will most likely develop and in
favorable upslope locations. Very little change between Monday and
Tuesday, so the general pattern and expectation from this discussion
is relatively the same for both days. On top of all of the heavy
rainfall talk, there will also be the threat for isolated strong to
severe thunderstorms each day as well. Confidence that the
ingredients for heavy rainfall/flash flooding continues to increase
with each model run and should be taken seriously. One last threat
will be landslides in the mountains, especially in the favorable
upslope peaks along the Blue Ridge Escarpment. High temperatures
will run below normal during the short-term with a weak summertime
wedge expected, but lows will be above normal due to extensive cloud
cover.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
As of 215 PM EDT Saturday: The forecast trend continues to gradually
push the remnants of Fred further west and both the GFS and ECMWF
allows the leftovers to get absorbed soon after making landfall over
the Deep South Tuesday into Wednesday. Either way, the tropical
airmass will hold steady as the stalled frontal boundary remains
in the vicinity of the CFWA and the tropical moisture continues
to be transported into the region during the middle part of next
week. The global models still differ in QPF amounts with the ECMWF
much wetter than the GFS, with a good bullseye over the southwest
mountains. This does not help with overall confidence this far out,
but the pattern will remain persistent with a wetter trend across
the CFWA.

More uncertainties follow up during the second half of the medium
range as the GFS and ECMWF produce different synoptic patterns. The
latest GFS builds an upper ridge along the East Coast and allows
for a slightly drier airmass to prevail of the CFWA, while the
ECMWF stays active and sends an upper low over the OH Valley
and digs lower heights into the western Carolinas and northeast
Georgia. Diurnal activity will stay put in the forecast despite
the large discrepancies between the model guidance this far out
due to the typical nature of summertime convection and nothing in
the model guidance that indicates this pattern will be altered in
any way. Temperatures will likely rebound a degree or two each
day during the extended period as the stalled frontal boundary
slowly dissipates and less cloud cover allows for more insolation
to reach the surface.

&&

.AVIATION /19Z SATURDAY THROUGH THURSDAY/...
At KCLT and elsewhere: Scattered convection has developed across the
Terminal Forecast Area this afternoon, and VCSH/VCTS and tempos for
TSRA are warranted at most sites this afternoon. Convection has been
a bit slow to develop this afternoon across the mountains, but we
are still anticipating solid scattered to numerous coverage of cells
later this afternoon, with this activity possibly bringing another
round of scattered convection to the Piedmont and foothills this
evening. Therefore, additional tempos may need to be introduced
later. While convection will diminish in coverage and intensity this
evening, some degree of shower coverage and perhaps a TS or two will
persist into the overnight as a weak surface front sags south into
the area. The expectation of widespread VFR cloud cover this evening
is resulting in somewhat low confidence in cig/visby trends
overnight into early Sunday, although guidance is hitting low
visibility fairly hard at KAVL and vicinity. For now, we are
advertising 2SM/SCT005 around daybreak at KAVL. Low cigs (LIFR) are
also advertised at KHKY north of the weak frontal boundary.
Otherwise, the forecast is VFR except for a brief period of MVFR
conditions here and there Sunday morning.

Outlook: Fairly widespread shower and thunderstorm coverage remains
in the forecast for the late weekend and the early to middle part of
next week. Fog and low stratus will be possible each morning,
especially over mountain valleys, and in areas primed by rainfall
from the previous evening. Low restrictions are also likely with any
downpours.

Confidence Table...

            19-01Z        01-07Z        07-13Z        13-18Z
KCLT       High 100%     High 100%     High  94%     High  87%
KGSP       High 100%     High 100%     High  84%     High  96%
KAVL       High 100%     High  99%     High  91%     High  95%
KHKY       High 100%     High  94%     Med   71%     High  84%
KGMU       High 100%     High 100%     High  83%     High  90%
KAND       High 100%     High 100%     High  91%     High  80%

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...JDL
SHORT TERM...CAC
LONG TERM...CAC
AVIATION...JDL

Hazardous Weather Outlook
National Weather Service Greenville-Spartanburg SC
526 AM EDT Sat Aug 14 2021

GAZ010-017-018-026-028-029-NCZ033-035>037-048>053-056>059-062>065-
068>072-082-501>510-SCZ001>014-019-150930-
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-
526 AM EDT Sat Aug 14 2021

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

.DAY ONE...Today and tonight.

Scattered to numerous thunderstorms will develop across the western
Carolinas and northeast Georgia this afternoon and linger into the
evening. A few of these storms could become quite strong and produce
large hail, heavy rainfall, and damaging winds.

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

The remnants of tropical cyclone Fred may interact with an old
front to produce heavy rainfall early next week. This could result
in a flash flooding threat, especially in areas that receive
multiple rounds of heavy rainfall.

.SPOTTER INFORMATION STATEMENT...

None.

Krentz

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
217 PM EDT Sat Aug 14 2021

NCZ036-069>071-141845-
Gaston NC-Iredell NC-Lincoln NC-Mecklenburg NC-
217 PM EDT Sat Aug 14 2021

...A strong thunderstorm will impact portions of eastern Lincoln,
south central Iredell, northwestern Mecklenburg and northeastern
Gaston Counties through 245 PM EDT...

At 216 PM EDT, Doppler radar was tracking a strong thunderstorm 8
miles west of Huntersville, or near Westport, moving northeast 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. Torrential rainfall may cause localized flooding.

Locations impacted include...
Huntersville, Cornelius, Davidson, Westport, Lake Norman, Denver,
Ramsey Creek Park, Mooresville, Lowesville and Lucia.

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.

If on or near Lake Norman, get out of the water and move indoors or
inside a vehicle. Remember, lightning can strike out to 10 miles
from the parent thunderstorm. If you can hear thunder, you are close
enough to be struck by lightning. Move to safe shelter now! Do not
be caught on the water in a thunderstorm.

&&

LAT...LON 3541 8077 3534 8101 3550 8111 3555 8103
      3555 8096 3557 8096 3559 8093 3561 8094
      3565 8087 3551 8078 3550 8078 3549 8079
      3542 8075
TIME...MOT...LOC 1816Z 241DEG 9KT 3546 8099

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

HG

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
219 PM EDT Sat Aug 14 2021

NCZ082-141845-
Union NC-
219 PM EDT Sat Aug 14 2021

...A strong thunderstorm will impact portions of northeastern Union
County through 245 PM EDT...

At 219 PM EDT, Doppler radar was tracking a strong thunderstorm 14
miles northwest of Wadesboro, or 8 miles northeast of Marshville,
moving northwest 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...
Unionville, Fairview In Union County and New Salem.

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.

&&

LAT...LON 3499 8030 3507 8055 3517 8048 3516 8044
      3517 8042 3516 8041 3518 8037 3517 8036
      3518 8031 3519 8030 3519 8028
TIME...MOT...LOC 1819Z 121DEG 10KT 3509 8028

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

HG

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
222 PM EDT Sat Aug 14 2021

SCZ011-019-141845-
Abbeville SC-Greenwood SC-
222 PM EDT Sat Aug 14 2021

...A strong thunderstorm will impact portions of southeastern
Abbeville and southwestern Greenwood Counties through 245 PM EDT...

At 222 PM EDT, Doppler radar was tracking a strong thunderstorm 10
miles south of Greenwood, or 9 miles northeast of Troy. This storm
was nearly stationary.

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...
Troy, Promised Land, Bradley, Callison, Epworth and Kirksey.

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 3399 8221 3402 8225 3397 8230 3417 8230
      3413 8205 3398 8205 3398 8208 3399 8210
      3399 8215 3397 8217 3397 8218
TIME...MOT...LOC 1822Z 088DEG 4KT 3404 8214

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

HG

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
231 PM EDT Sat Aug 14 2021

SCZ011-019-141900-
Abbeville SC-Greenwood SC-
231 PM EDT Sat Aug 14 2021

...A strong thunderstorm will impact portions of northeastern
Abbeville and northwestern Greenwood Counties through 300 PM EDT...

At 231 PM EDT, Doppler radar was tracking a strong thunderstorm 10
miles north of Abbeville, or near Shoals Junction. This storm was
nearly stationary.

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...
Abbeville, Due West, Donalds, Cokesbury, Hodges, Shoals Junction and
Ware Shoals.

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 3415 8239 3436 8251 3441 8243 3444 8228
      3428 8219
TIME...MOT...LOC 1831Z 063DEG 4KT 3433 8232

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

HG

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
237 PM EDT Sat Aug 14 2021

SCZ005-006-010-141900-
Greater Pickens SC-Anderson SC-Greater Greenville SC-
237 PM EDT Sat Aug 14 2021

...A strong thunderstorm will impact portions of south central
Greenville, northeastern Anderson and east central Pickens Counties
through 300 PM EDT...

At 237 PM EDT, Doppler radar was tracking a strong thunderstorm 7
miles southeast of Easley, or near Piedmont, moving south 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...
Easley, Powdersville, Piedmont, Williamston, West Pelzer, Donaldson
Center, Welcome, Northlake and West Greenville.

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 3483 8258 3479 8237 3453 8239 3459 8271
TIME...MOT...LOC 1837Z 013DEG 10KT 3474 8250

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

HG

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
246 PM EDT Sat Aug 14 2021

NCZ056-069-070-141915-
Gaston NC-Lincoln NC-Catawba NC-
246 PM EDT Sat Aug 14 2021

...Strong thunderstorms will impact portions of eastern Catawba,
central Lincoln and north central Gaston Counties through 315 PM
EDT...

At 246 PM EDT, Doppler radar was tracking strong thunderstorms along
a line extending from near Newton to 6 miles south of Lincolnton.
Movement was northeast 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...
Newton, Lincolnton, Conover, Bessemer City, Maiden, Claremont,
Catawba, High Shoals, Boger City and Iron Station.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

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

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

&&

LAT...LON 3580 8113 3577 8110 3577 8109 3576 8109
      3574 8107 3571 8107 3571 8104 3543 8104
      3526 8129 3567 8127 3582 8114
TIME...MOT...LOC 1846Z 220DEG 10KT 3565 8122 3539 8124

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

HG