Severe Thunderstorm Warning 126, NWS Greenville-Spartanburg, SC

468 
WWUS52 KGSP 141836
SVSGSP

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

SCC083-087-141900-
/O.CON.KGSP.SV.W.0126.000000T0000Z-210814T1900Z/
Spartanburg SC-Union SC-
236 PM EDT Sat Aug 14 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 300 PM EDT
FOR SOUTHEASTERN SPARTANBURG AND NORTHWESTERN UNION COUNTIES...

At 236 PM EDT, a severe thunderstorm was located 8 miles northwest of
Union, or 5 miles southwest of Jonesville, moving south at 10 mph.

HAZARD...60 mph wind gusts and quarter size hail.

SOURCE...Radar indicated.

IMPACT...Minor hail damage to vehicles is expected. Expect wind 
         damage to trees and power lines.

Locations impacted include...
Union, Buffalo, Jonesville, Rose Hill State Park, Cross Keys, Cross
Anchor, Sedalia, Pacolet and Croft State Park.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

Continuous cloud to ground lightning is occurring with this storm.
Move indoors immediately. Lightning is one of nature's leading
killers. Remember, if you can hear thunder, you are close enough to
be struck by lightning.

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

Please report damaging winds, hail, or flooding to the National
Weather Service by calling toll free, 1, 800, 2 6 7, 8 1 0 1, or by
posting on our Facebook page, or Tweet it using hashtag nwsgsp. Your
message should describe the event and the specific location where it
occurred.

&&

LAT...LON 3489 8181 3490 8181 3487 8160 3459 8161
      3464 8193
TIME...MOT...LOC 1836Z 013DEG 10KT 3478 8175 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

HG

229 
WWUS52 KGSP 141900
SVSGSP

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

SCC083-087-141910-
/O.EXP.KGSP.SV.W.0126.000000T0000Z-210814T1900Z/
Spartanburg SC-Union SC-
300 PM EDT Sat Aug 14 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN SPARTANBURG AND
NORTHWESTERN UNION COUNTIES HAS EXPIRED...
                
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 allowed to expire.  However, gusty 
winds and heavy rain are still possible with this thunderstorm.

LAT...LON 3489 8181 3490 8181 3487 8160 3459 8161
      3464 8193
TIME...MOT...LOC 1900Z 011DEG 8KT 3473 8176 

$$

HG

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
1103 AM EDT Sat Aug 14 2021

.SYNOPSIS...
A stormy pattern will persist over the area through the weekend,
with scattered if not numerous showers and thunderstorms developing
each afternoon. Temperatures will remain above normal through
Saturday. Cooler but still rainy weather will arrive Sunday with a
stalling cold front and possibly impacts from the remnants of
Tropical Storm Fred in the early to middle part of next week.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 1045 am: Strong insolation has resulted in moderate
destabilization already this morning, with sbCAPE exceeding 2000
J/kg just about everywhere across the CWA per the latest SPC
mesoanalysis. As a result, the cu field is developing quickly along
the ridgetops of the southern Appalachians, and some of these will
evolve into isolated to widely scattered convection over the next
1-2 hours, with numerous coverage expected across much of our
mountain zones during mid/late afternoon as the atmosphere further
destabilizes to the tune of 3000-4000 J/kg of sbCAPE. Meanwhile, a
lee/ pre-frontal trough, differential heating regions, and outflow
boundaries originating from high terrain convection will provide
additional foci for deep convection across the foothills and
Piedmont, where solid scattered coverage is expected by late
afternoon, warranting 40-60% chances in those areas.

Some degree of convective coverage is expected to linger until at
least midnight across the NC zones as a weak sfc bndry sags into the
area from the north and makes for an enhanced focusing zone. Shear
will remain weak, but the expected uptick in coverage, strong
instability, and robust downdraft CAPE will yield an increase in the
potential for pulse cells to produce strong-to-damaging microbursts
this afternoon/evening. Slow moving and back-building storms will
also be possible and isol flooding will be another threat into the
later evening. Lingering isol storms should continue overnight, yet
with limited severity due to weakening instability.

Another hot and humid day is on tap as temps rise into the m90s
outside the mtns and u80s across the mtn valleys. Peak heat index
values of 99-102 can again be expected across mainly the Piedmont
this afternoon. Mins will also remain a few degrees abv normal.

&&

.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
As of 304 AM EDT Saturday: It looks like Sunday will be the
start of a wet period across the western Carolinas and northeast
Georgia. An initial surge of higher PW air will arrive from the
sub-tropical Atlantic during the day, while guidance agrees that
a sfc boundary will be draped across the region. The boundary
will provide an excellent focus for the development of widespread
showers and thunderstorms during the afternoon, especially as bits
of vorticity emanating from the circulation of Fred move northward
to intersect the boundary later in the day. A transition from a
low-end severe threat to more of a flash flood threat will occur by
Sunday evening as warm cloud depth increases, moisture increases,
and lapse rates weaken. The tropical air mass may get undercut by
a shallow wedge of slightly cooler air Sunday night as a sfc high
moves slowly over New England. Guidance suggests this will morph
into a weak summertime diurnal cold air damming wedge by Monday
morning. A late evening uptick in convective precip could happen
across the region, aided by upglide/moisture transport from the
southeast over the top of the nascent wedge. Once established, moist
tropical upslope/upglide flow will persist over the region Monday
and Monday night, warranting the continuation of likely/categorical
precip probs. We hesitate to use the term 'cold air damming' as
temps will probably still climb into the lower 80s east of the
mtns on Monday, but the pattern will certainly resemble an in-
situ CAD wedge. Rainfall amounts are the main forecast problem,
and possible flash flooding is the main concern. At this time,
the trend in the guidance is toward lower potential, reflected
in a downturn in the QPF amounts. Nevertheless, we collect many
of the ingredients for heavy rain/flash flooding during the
first part of the week, so we will keep the potential at the
forefront, and will eventually probably have to consider some
sort of Watch.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
As of 320 AM EDT Saturday: By Tuesday morning, our attention
will turn toward what remains of Fred moving northward over the
southeastern US. The forecast trend has been to take the bulk of
the system on a more westward track, and both the GFS and ECMWF
want to wash out whats left of it over AL on Tuesday. Whatever the
case, the situation over the western Carolinas will be tied more to
the persistent transport of tropical moisture over the diffuse sfc
boundary draped just south of the area into the middle part of the
week. Even without Fred, we may have problems. Tuesday might have
the best potential for heavier rain as another surge of moisture
takes place. The increasing cloud cover and ensuing widespread
precip may keep temps from getting out of the 70s. High precip probs
will continue Tuesday night and Wednesday as the old boundary lifts
northward. Confidence is modest by mid-week, as a matter of course,
especially with the GFS being somewhat unimpressed with its QPF and
the ECMWF showing a bullseye over southwest NC. Precip chances will
remain relatively high as we transition back toward something more
diurnal late in the week because we retain significant sub-tropical
moisture with a SW flow aloft.

&&

.AVIATION /15Z SATURDAY THROUGH WEDNESDAY/...
At KCLT and elsewhere: Convective activity will continue to wane
across the ern zones near KCLT this morning. With previous heavy
rainfall at KCLT, have included TEMPO flight restrictions before
daybreak of IFR VSBY and MVFR CIGS thru 12z. At KAVL, a good chance
exists for LIFR to VLIFR CIGs and VSBY later this morning as well. A
cold front works into the area this afternoon and all sites will be
under the gun for thunderstorms with PROB30 TSRA and prevailing TSRA
included thru the afternoon and evening. Kept showers in the
vicinity thru the end of the period at all sites except KAND. Winds
will remain generally aligned sw/ly across all terminals with
low-end gusts possible outside convec this afternoon.

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...

            15-21Z        21-03Z        03-09Z        09-12Z
KCLT       High 100%     High 100%     High 100%     High  92%
KGSP       High 100%     High 100%     High 100%     High  81%
KAVL       High 100%     High 100%     High  91%     Med   64%
KHKY       High 100%     High 100%     High  91%     High  82%
KGMU       High 100%     High 100%     High 100%     Med   69%
KAND       High 100%     High 100%     High 100%     High  98%

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/SBK
NEAR TERM...JDL/SBK
SHORT TERM...PM
LONG TERM...PM
AVIATION...SBK

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
106 PM EDT Sat Aug 14 2021

SCZ006-141745-
Greater Greenville SC-
106 PM EDT Sat Aug 14 2021

...A THUNDERSTORM WITH TORRENTIAL RAINFALL WILL IMPACT EAST CENTRAL
GREENVILLE COUNTY UNTIL 145 PM EDT...

At 105 PM EDT, Doppler radar was tracking a thunderstorm with
torrential rainfall 8 miles east of Greenville Downtown, or near GSP
Airport. This storm was nearly stationary.

Locations to be impacted include...
Greer, Taylors, GSP Airport, Five Forks, Mauldin and Greenville
Eastside.

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.

&&

LAT...LON 3480 8230 3492 8233 3495 8222 3489 8222
      3485 8223 3485 8221 3482 8221
TIME...MOT...LOC 1705Z 156DEG 0KT 3488 8225

LANE

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

SCZ008-141815-
Cherokee SC-
147 PM EDT Sat Aug 14 2021

...A strong thunderstorm will impact portions of west central
Cherokee County through 215 PM EDT...

At 147 PM EDT, Doppler radar was tracking a strong thunderstorm 5
miles west of Gaffney, or near Cowpens, moving east at 5 mph.

HAZARD...Winds in excess of 40 mph and half inch 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...
Gaffney and Thicketty.

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 8177 3503 8179 3508 8180 3509 8165
      3495 8165
TIME...MOT...LOC 1747Z 273DEG 5KT 3504 8175

MAX HAIL SIZE...0.50 IN
MAX WIND GUST...40 MPH

LANE

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

SCZ007-013-141845-
Union SC-Spartanburg SC-
209 PM EDT Sat Aug 14 2021

...A THUNDERSTORM WITH INTENSE LIGHTNING AND TORRENTIAL RAINFALL WILL
IMPACT SOUTHEASTERN SPARTANBURG AND NORTHWESTERN UNION COUNTIES UNTIL
245 PM EDT...

At 209 PM EDT, Doppler radar was tracking a thunderstorm with intense
lightning and torrential rainfall 8 miles northwest of Union, or near
Jonesville, moving south at 10 mph.

Locations to be impacted include...
Union, Buffalo, Jonesville, Pacolet, Monarch Mill and Croft State
Park.

Very heavy rainfall rates up to 1 to 2 inches per hour will be
possible in these areas.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

The combination of gusty winds and saturated soil conditions will
cause scattered trees and power lines to fall. Seek shelter inside an
interior room.

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 3490 8181 3487 8160 3463 8160 3468 8192
TIME...MOT...LOC 1809Z 011DEG 8KT 3482 8173

HG