Damaging Wind in South Carolina, June 30, 2021

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
235 PM EDT Wed Jun 30 2021

.SYNOPSIS...
High pressure off the Atlantic coast weakens as a cold front drops
into the area from the Ohio River Valley by Friday. Increasing
moisture between the high and cold front will allow showers and
thunderstorms to develop each day with increasing coverage through
late Friday. The front moves east of the area by Saturday and
Independence Day. Near seasonal conditions expected early next week.

&&

.NEAR TERM /THROUGH THURSDAY/...
As of 155 pm: Scattered convection has developed within an axis of
strong instability (sbCAPE > 3000 J/kg) across the Piedmont from the
SC/GA Lakelands through the southern NC Piedmont. The few model
sources that picked up on this trend depicted coverage steadily
diminishing such that there would not be much left outside the mtns
by late afternoon...presumably as deeper mixing resulted in
decreasing surface dewpoints/CAPE and increasing LFCs. We are
actually, beginning to see the effects of this process to the north
of the existing convection, as dewpoints has mixed out to the
mid-60s in many areas north of I-85. We are therefore allowing  PoPs
to peak outside the mountains now, with a steadily diminishing trend
through the afternoon/evening. Meanwhile, we still anticipate a
slight uptick in coverage over the high terrain. We've already seen
a strong storm or two over the Piedmont...not surprising given the
robust buoyancy...as well as locally heavy rainfall owing to slow
cell movement, and a very localized/brief pulse severe storm or
excessive rainfall event can't be ruled out going forward. Most of
any lingering convection should dissipate this evening, but a small
PoP is maintained across far southwest NC, where short term guidance
depicts the approach of a deep moisture plume in advance of cold
front. Min temps will be a couple of degrees above normal.

For Thursday, short term guidance suggests weaker instability
compared with today, owing primarily to poorer mid-level lapse
rates. As such, much of the day will likely be convection-free,
other than some isolated/widely scattered activity over the high
terrain. However, a significant uptick in PoP is advertised from
late afternoon into early evening, as height falls begin
overspreading the region, and attendant frontal zone and deep
moisture plume begin impacting the southern Appalachians. By 00Z
Friday, chances range from likely/categorical across the NC mtns, to
a small chance across the Piedmont. Max temps are forecast to reach
right around normal.

&&

.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY NIGHT/...
As of 200 PM EDT Wednesday: A dynamic upper trough will swing
thru the Ohio Valley to the Mid-Atlantic on Friday, bringing in
a moist cold front into the area. The front will drift from NW
to SE thru the forecast area during the day Friday, accompanied
by deep-layer Q-vector convergence and right-rear quadrant upper
jet divergence. So categorical PoPs still looks good. Instability
will be on the modest side (generally under 2000 J/kg), and
shear remains weak. So the severe threat will remain marginal at
best. The bigger concern will be heavy rainfall, given good forcing
and precip coverage. PWATs will be around 2" with the front, so
any training cells or upslope-enhanced areas could see exceesive
rainfall/localized flooding. Temps will start out above normal
Thursday night/Friday morning, then top out well below normal with
the rain and clouds Friday aftn.

Guidance continues to trend faster with bringing dry air in behind
the front and cutting off PoPs Friday night thru Saturday. So
now have just lingering PoPs Friday evening, dropping below 10%
by daybreak Saturday. The air mass that builds in the front's wake
will be unseasonably dry for early July, with dewpts in the 50s
to lower 60s. So low temps will be a few deg below normal both
Friday night and Saturday night. Highs Saturday will be a couple
categories below normal under mostly sunny skies.

&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
As of 230 PM EDT Wednesday: The Fourth of July still looks very
nice, with the center of weak, dry sfc high pressure over the
region. Sunny skies and below normal humidity with near to slightly
below normal temps are expected. The nice weather will continue into
Monday, but humidity will begin to recover and temps will be back
to the 90-92 deg range across the Piedmont. The model consensus
still shows no mentionable PoPs, but it wouldn't surprise me if
an isolated shower or two pops in the high terrain.

From Tuesday onward, the upper pattern shows some upper ridging
over the Southeast and a more typical Bermuda High setting up. This
will bring Gulf moisture back into the area and a return to typical
mid-Summer diurnal convection and muggy conditions. Temps will be
near climo.

&&

.AVIATION /19Z WEDNESDAY THROUGH MONDAY/...
At KCLT and elsewhere:  Isolated to scattered convection has
developed across the Terminal Forecast Area this afternoon, with the
best coverage observed from near KAND to KCLT. VCSH has been added
to all terminals except KHKY. This is allowed to go away at most
sites around 21Z, as there are indications that coverage may
actually diminish from mid-afternoon on, at least outside the
mountains. (VCSH/VCTS continue at KAVL through 00Z). Any lingering
convection will steadily diminish this evening. Valley fog/low
stratus will return late tonight/early Thursday, although it is
unclear at this time how widespread it will become. For now, 2SM/
SCT003 is advertised at KAVL from 09-13Z. Winds will generally favor
SW at 5-10 kts through much of the period.

Outlook: A cold front is expected to bring periods of numerous to
widespread convective coverage to the area from late Thu through
early Saturday. Fog and low stratus will be possible each morning as
well, primarily in the mountain valleys. Drying is expected from
later Saturday into early next week.

Confidence Table...

            18-24Z        00-06Z        06-12Z        12-18Z
KCLT       High 100%     High 100%     High 100%     High 100%
KGSP       High 100%     High 100%     High 100%     High  99%
KAVL       High 100%     High 100%     Med   69%     High  83%
KHKY       High 100%     High 100%     High 100%     High 100%
KGMU       High 100%     High 100%     High 100%     High  99%
KAND       High 100%     High 100%     High  98%     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...DEO
NEAR TERM...JDL
SHORT TERM...ARK
LONG TERM...ARK
AVIATION...JDL

Hazardous Weather Outlook
National Weather Service Greenville-Spartanburg SC
352 PM EDT Wed Jun 30 2021

GAZ010-017-018-026-028-029-NCZ033-035>037-048>053-056>059-062>065-
068>072-082-501>510-SCZ001>014-019-012000-
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-
352 PM EDT Wed Jun 30 2021

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

.DAY ONE...This afternoon and tonight.

Scattered thunderstorms are expected to continue into the early
evening, especially across the mountains although isolated storms cannot
be ruled out in the NC Piedmont and SC Upstate. Cloud- to- ground
lightning and brief, heavy rainfall are the main threats.

.DAYS TWO THROUGH SEVEN...Thursday through Tuesday.

Showers and thunderstorms are expected to increase in coverage ahead
of a cold front Thursday and remain over the area Friday and Friday
night as the front slowly crosses the area. Areas of heavy rainfall
will be possible, potentially leading to isolated flash flooding.

.SPOTTER INFORMATION STATEMENT...

None.

MPR

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
151 PM EDT Wed Jun 30 2021

NCZ072-301815-
Cabarrus NC-
151 PM EDT Wed Jun 30 2021

...A STRONG THUNDERSTORM WILL IMPACT CENTRAL CABARRUS COUNTY UNTIL
215 PM EDT...

At 151 PM EDT, Doppler radar was tracking a strong thunderstorm 4
miles southeast of Downtown Concord, moving southwest at 10 mph.

Locations to be impacted include...
Downtown Concord, Harrisburg, Charlotte Motor Speedway, Midland, West
Concord and Mt Pleasant.

Wind gusts up to 35 mph and pea size hail 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 3527 8045 3519 8051 3527 8067 3534 8069
      3536 8072 3546 8055 3535 8040
TIME...MOT...LOC 1751Z 043DEG 10KT 3535 8054

ARK

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
305 PM EDT Wed Jun 30 2021

GAZ028-301930-
Hart GA-
305 PM EDT Wed Jun 30 2021

...A CLUSTER OF THUNDERSTORMS WILL IMPACT WESTERN HART COUNTY UNTIL
330 PM EDT...

At 304 PM EDT, Doppler radar indicated a cluster of thunderstorms
along a line extending from near Hartwell to 11 miles southeast of
Carnesville. These storms were nearly stationary.

Locations to be impacted include...
Hartwell, Bowersville, Canon, Royston, Reed Creek and Vanna.

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 3423 8308 3427 8312 3428 8310 3434 8310
      3435 8311 3441 8310 3444 8305 3444 8302
      3442 8299 3443 8295 3439 8289 3438 8286
      3423 8299
TIME...MOT...LOC 1904Z 109DEG 1KT 3438 8297 3425 8308

TDP

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
335 PM EDT Wed Jun 30 2021

NCZ070-071-SCZ009-302000-
Gaston NC-Mecklenburg NC-York SC-
335 PM EDT Wed Jun 30 2021

...A STRONG THUNDERSTORM WILL IMPACT SOUTHWESTERN MECKLENBURG...
SOUTHEASTERN GASTON AND NORTHEASTERN YORK COUNTIES UNTIL 400 PM
EDT...

At 335 PM EDT, Doppler radar was tracking a strong thunderstorm 7
miles north of York, or near Clover, moving northeast at 15 mph.

Locations to be impacted include...
York, Gastonia, Belmont, Tega Cay, Clover, Cramerton, Mcadenville,
Steele Creek, Carowinds and Lake Wylie.

Wind gusts up to 40 mph and pea size hail will be possible in these
areas.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Gusty winds can blow down trees that are dead, or that have weakened
root systems. Outdoor furniture and similar items can be tossed
around if not anchored. Seek shelter indoors.

&&

LAT...LON 3497 8122 3514 8132 3530 8104 3505 8090
      3505 8091
TIME...MOT...LOC 1935Z 244DEG 12KT 3509 8119

TDP

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
423 PM EDT Wed Jun 30 2021

NCZ071-072-302100-
Cabarrus NC-Mecklenburg NC-
423 PM EDT Wed Jun 30 2021

...A STRONG THUNDERSTORM WILL IMPACT SOUTHWESTERN CABARRUS AND
CENTRAL MECKLENBURG COUNTIES UNTIL 500 PM EDT...

At 423 PM EDT, Doppler radar was tracking a strong thunderstorm 5
miles northeast of Uptown Charlotte, or over Hidden Valley. This
storm was nearly stationary.

Locations to be impacted include...
Uptown Charlotte, Huntersville, Northeast Charlotte, East Charlotte,
Harrisburg, University City, Reedy Creek Park, The Plaza, Charlotte
Motor Speedway and Hidden Valley.

Wind gusts up to 40 mph and pea size hail 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.

&&

LAT...LON 3517 8070 3524 8090 3545 8086 3535 8055
TIME...MOT...LOC 2023Z 201DEG 4KT 3528 8077

TDP

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
448 PM EDT Wed Jun 30 2021

SCZ007-012-302115-
Laurens SC-Spartanburg SC-
448 PM EDT Wed Jun 30 2021

...A STRONG THUNDERSTORM WILL IMPACT NORTH CENTRAL LAURENS AND SOUTH
CENTRAL SPARTANBURG COUNTIES UNTIL 515 PM EDT...

At 448 PM EDT, Doppler radar was tracking a strong thunderstorm 11
miles north of Laurens, or 7 miles southeast of Woodruff. This storm
was nearly stationary.

Locations to be impacted include...
Enoree, Ora and Cross Anchor.

Wind gusts up to 40 mph and half inch hail 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.

This storm may intensify, so be certain to monitor local radio and tv
stations, as well as local cable tv outlets for additional
information and possible warnings from the National Weather Service.

&&

LAT...LON 3454 8202 3472 8208 3473 8188 3461 8185
      3459 8185 3457 8184
TIME...MOT...LOC 2048Z 080DEG 3KT 3465 8195

TDP

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
450 PM EDT Wed Jun 30 2021

NCZ071-302115-
Mecklenburg NC-
450 PM EDT Wed Jun 30 2021

...A CLUSTER OF THUNDERSTORMS WILL IMPACT SOUTHEASTERN MECKLENBURG
COUNTY UNTIL 515 PM EDT...

At 450 PM EDT, Doppler radar indicated the leading edge of a cluster
of thunderstorms along a line extending from 6 miles northeast of
Uptown Charlotte to 7 miles north of Indian Land. These storms were
nearly stationary.

Locations to be impacted include...
Uptown Charlotte, Central Charlotte, South Charlotte, Northeast
Charlotte, Southwest Charlotte, East Charlotte, Pineville, Freedom
Park, University City and Reedy Creek Park.

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 3503 8077 3502 8082 3502 8086 3511 8093
      3510 8095 3535 8082 3539 8075 3535 8069
      3527 8067 3526 8066
TIME...MOT...LOC 2050Z 251DEG 0KT 3531 8078 3511 8088

TDP