Special Weather Statement, NWS Greenville-Spartanburg, SC

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
538 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 530 pm: Afternoon convection developed mainly along a weak
trough axis stretched through Piedmont areas of the western
Carolinas. Additional isolated to scattered cells are forming along
residual outflows, but the convection allowing models have
diminishing coverage through early this evening, albeit with a very
slight uptick in the mountains. This trend has been followed on the
latest update. This should permit the heavy rainfall and isolated
severe threat to quickly diminish. Most of any lingering convection
should dissipate this evening, but a small PoP is maintained across
far southwest NC tonight, 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 /22Z WEDNESDAY THROUGH MONDAY/...
At KCLT and elsewhere:  Earlier convection threatening the
Upstate TAF sites and KCLT appears to be diminishing or moving away
from the affected airfields, so TEMPO TSRA can be removed shortly.
Otherwise, should be able to ride on VCSH for a while through early
evening until the remainder of the coverage winds down. Otherwise,
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. PROB30
for TSRA is included for late tomorrow in the modest instability
ahead of the next approaching cold front.

Outlook: A cold front is expected to bring periods of numerous to
widespread thunderstorm 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...

            21-03z        03-09Z        09-15Z        15-18Z
KCLT       High 100%     High 100%     High 100%     High 100%
KGSP       High 100%     High 100%     High 100%     High 100%
KAVL       High 100%     High 100%     Low   48%     High 100%
KHKY       High 100%     High 100%     High 100%     High 100%
KGMU       High 100%     High 100%     High 100%     High 100%
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
NEAR TERM...HG/JDL
SHORT TERM...ARK
LONG TERM...ARK
AVIATION...HG/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
507 PM EDT Wed Jun 30 2021

SCZ006-302130-
Greater Greenville SC-
507 PM EDT Wed Jun 30 2021

...A STRONG THUNDERSTORM WILL IMPACT EAST CENTRAL GREENVILLE COUNTY
UNTIL 530 PM EDT...

At 507 PM EDT, Doppler radar was tracking a strong thunderstorm near
Greenville Downtown, or near Cherrydale Point. This storm was nearly
stationary.

Locations to be impacted include...
Greenville Downtown, Greenville Eastside, Taylors, Cherrydale Point,
Furman University, Paris Mountain State Park, West Greenville and
Berea.

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.

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 3484 8226 3480 8241 3493 8247 3497 8227
TIME...MOT...LOC 2107Z 165DEG 1KT 3490 8236

TDP

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
530 PM EDT WED JUN 30 2021

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

0530 PM     TSTM WND DMG     3 SW TAYLORS            34.89N 82.36W
06/30/2021                   GREENVILLE         SC   PUBLIC

             REPORTED TREES DOWN RESULTING IN POWER OUTAGES

&&

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

NCZ071-072-082-302200-
Union NC-Cabarrus NC-Mecklenburg NC-
534 PM EDT Wed Jun 30 2021

...A CLUSTER OF THUNDERSTORMS WILL IMPACT SOUTHWESTERN CABARRUS...
SOUTHEASTERN MECKLENBURG AND NORTHWESTERN UNION COUNTIES UNTIL 600 PM
EDT...

At 534 PM EDT, Doppler radar indicated a cluster of thunderstorms
along a line extending from 9 miles southwest of Downtown Concord to
8 miles northeast of Indian Land, and moving east at 10 mph.

Locations to be impacted include...
Downtown Concord, East Charlotte, Matthews, Mint Hill, Indian Trail,
Weddington, Stallings, Harrisburg, Lake Park and Hemby Bridge.

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 3539 8056 3506 8058 3502 8078 3534 8075
TIME...MOT...LOC 2134Z 249DEG 8KT 3529 8069 3508 8073

TDP

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

NCZ058-302315-
Graham NC-
652 PM EDT Wed Jun 30 2021

...A THUNDERSTORM WITH TORRENTIAL RAINFALL WILL IMPACT WESTERN GRAHAM
COUNTY UNTIL 715 PM EDT...

At 652 PM EDT, Doppler radar was tracking a thunderstorm with
torrential rainfall 7 miles west of Robbinsville, or 5 miles
southwest of Town Of Santeetlah, moving south at 5 mph.

Locations to be impacted include...
Tapoco.

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 3535 8403 3537 8401 3540 8402 3544 8393
      3526 8384 3525 8385 3524 8390 3522 8395
      3522 8397 3524 8401 3527 8401 3529 8403
      3531 8402 3532 8404
TIME...MOT...LOC 2252Z 339DEG 5KT 3531 8395

TDP

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

NCZ052-053-010100-
Buncombe NC-Haywood NC-
830 PM EDT Wed Jun 30 2021

...A STRONG THUNDERSTORM WILL IMPACT SOUTHEASTERN HAYWOOD AND
SOUTHWESTERN BUNCOMBE COUNTIES UNTIL 900 PM EDT...

At 830 PM EDT, Doppler radar was tracking a strong thunderstorm 10
miles east of Waynesville, or 4 miles south of Canton, moving east at
10 mph.

Locations to be impacted include...
Canton, Clyde, Mount Pisgah, B.R. Parkway-Mount Pisgah To The Nc
Arboretum, Candler and Cruso.

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 3545 8264 3546 8267 3545 8269 3545 8270
      3543 8274 3542 8275 3541 8275 3540 8276
      3538 8287 3554 8292 3561 8269
TIME...MOT...LOC 0030Z 258DEG 7KT 3547 8281

TDP

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

NCZ062-010215-
Macon NC-
946 PM EDT Wed Jun 30 2021

...AN AREA OF HEAVY RAIN WILL IMPACT NORTH CENTRAL MACON COUNTY UNTIL
1015 PM EDT...

At 946 PM EDT, Doppler radar indicated an area of heavy rain along a
line extending from 8 miles north of Franklin to 9 miles southwest
of Sylva. This heavy rain nearly stationary.

Locations to be impacted include...
Cowee.

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 3530 8346 3530 8345 3532 8345 3532 8344
      3533 8334 3528 8331 3526 8342
TIME...MOT...LOC 0146Z 091DEG 1KT 3530 8341 3530 8336

TDP