Special Weather Statement, NWS Greenville-Spartanburg, SC

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
250 PM EDT Mon Jul 12 2021

.SYNOPSIS...
A Bermuda high will maintain seasonably hot and humid conditions,
with afternoon to evening showers and thunderstorms, through at
least the end of the week.

&&

.NEAR TERM /THROUGH TUESDAY/...
As of 215 PM EDT Monday: We're currently seeing sct convection
over the parts of the Upstate and NE GA, as well as the Northern
NC mtns. Still expecting some increase in coverage thru the late
aftn, however based on the most recent CAM trends it's looking
like most of the CWA will see isolated to sct coverage at best
thru the rest of today/tonight.

Otherwise, thru the near-term period there won't be much change
with regards to the large-scale pattern. The Southeast will remain
situated between the persistent subtropical upper ridge to our east
and an embedded upper trof/closed upper low centered over the MS
River Valley to our west. Towards the end of the period tomorrow,
the upper trof/low will begin to lift northward and deamplify.
At the sfc, warm and moist SLY flow will persist over the region
thru the near-term with PWs in excess of 1.75 inches. Mid/upper
level forcing will remain weak, however the low-level SLY to SWLY
flow should provide some support for convective development again
tomorrow, especially across the the higher terrain. Severe potential
once again appears minimal, with slightly better potential over
the higher terrain. Overall, heavy rainfall/flash flooding appears
to be the bigger threat. Temps will remain at or slightly above
normal for mid-July.

&&

.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/...
As of 205 pm Monday: The westerlies will be rather active across the
northern half of the country during the short term, with periodic
height falls allowing the weakening/suppression of the subtropical
anticyclone off the Mid-Atlantic coast. The latter feature will
evolve into an elongated ridge that cover much of the Southeast
through the period and into at least the early part of the medium
range, while the center of the weakening anticyclone may move into
the Carolina coast by the end of the period. That being the case,
probabilities for diurnal convection are expected to revert to
around normal (primarily 40-50% mountains to 30% Piedmont) by
Thursday afternoon/evening. Weak flow aloft will yield the usual
mid-summer convective threats: possibly a pulse severe storm or two
along with perhaps a highly localized excessive rainfall threat due
to slow-moving and/or anchoring cells. Temps are forecast to average
right around normal through the period.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
As of 215 pm Monday: Global models are converging toward a consensus
solution in allowing the subtropical ridge to become suppressed
south of the Conus by early next week, in response to periodic
height expected to impact the northern half of the country
throughout this week. In fact, there is a strong consensus in
anomalously low upper heights covering much of the eastern third of
the country by Day 7. It therefore appears increasingly likely that
a frontal zone will sag toward into the forecast area during the
Sunday/Monday time frame and enhance convective chances. Above climo
PoPs (with a strong, but not exclusively diurnal bent)...generally
50-70%...are advertised both days. While temps will be around normal
through much of the period, slightly below climo conditions are
advertised for next Monday in anticipation of lower heights along
with the likelihood of enhanced cloud cover and convective coverage.

&&

.AVIATION /19Z MONDAY THROUGH SATURDAY/...
At KCLT and Elsewhere: The typical summertime environment will
continue thru the taf period. Overall, confidence for the rest of
today and tonight is not quite as good as the past few days wrt
the overall coverage of convective storms. Although the persistent,
humid SLY flow is favorable for diurnal storms, the convection
allowing models have different depictions of coverage and timing.
So, I elected to simply maintain VCTS at most sites thru the evening
as my confidence wasn't quite high enough to include TEMPOs at
this time. Overall, less convective coverage is expected the farther
east you go, with KCLT just carrying a VCSH at this time. The other
taf sites transition from VCTS to VCSH later tonight once sfc-based
instability wanes. Winds will remain SLY to SWLY thru the period,
with some low-end gusts included until roughly 00z this evening.
Another round of fog/low stratus is likely Tuesday morning, but
outside of the usual mtn valleys, its development will largely
depend on which sites receive appreciable precipitation.

Outlook: An unsettled pattern, with morning fog/stratus restrictions
followed by afternoon/evening storms, is expected to persist thru the
week.

Confidence Table...

            19-01Z        01-07Z        07-13Z        13-18Z
KCLT       High 100%     High 100%     High 100%     High  98%
KGSP       High 100%     High 100%     High  96%     High  96%
KAVL       High 100%     High  99%     Med   74%     High  98%
KHKY       High 100%     High 100%     High  97%     High  96%
KGMU       High 100%     High 100%     High  87%     High  96%
KAND       High 100%     High  99%     High  96%     High  97%

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...JDL
NEAR TERM...JPT
SHORT TERM...JDL
LONG TERM...JDL
AVIATION...JPT

Hazardous Weather Outlook
National Weather Service Greenville-Spartanburg SC
554 AM EDT Mon Jul 12 2021

GAZ010-017-018-026-028-029-NCZ033-035>037-048>053-056>059-062>065-
068>072-082-501>510-SCZ001>014-019-131000-
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-
554 AM EDT Mon Jul 12 2021

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

.DAY ONE...Today and tonight.

Thunderstorms are expected to develop again this afternoon and
evening across the area. Storms should be most numerous across the
mountains and the western part of the Upstate, and scattered over the
remainder of Upstate South Carolina, the western Piedmont, and northeast
Georgia. Frequent cloud-to-ground lightning and heavy downpours are
the main threats from the storms, which could result in localized
flooding where storms persist. One or two of the storms could
become strong enough to produce damaging wind gusts and large hail.
The thunderstorms should diminish by late evening.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday.

Hazardous weather is not expected at this time.

.SPOTTER INFORMATION STATEMENT...

None.

PM

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
257 PM EDT Mon Jul 12 2021

SCZ007-012-013-121930-
Laurens SC-Union SC-Spartanburg SC-
257 PM EDT Mon Jul 12 2021

...A HEAVY RAIN SHOWER WITH EMBEDDED THUNDERSTORMS WILL IMPACT EAST
CENTRAL LAURENS... SOUTHEASTERN SPARTANBURG AND WESTERN UNION
COUNTIES UNTIL 330 PM EDT...

At 256 PM EDT, Doppler radar was tracking a heavy rain shower with
occasional thunderstorms 11 miles southwest of Union, or 7 miles
west of Rose Hill State Park, moving northeast at 10 mph.

Locations to be impacted include...
Union, Buffalo, Rose Hill State Park, Monarch Mill, Cross Keys, Cross
Anchor and Sedalia.

Wind gusts up to 40 mph, pea size hail and very heavy rainfall rates
up to 2 inches per hour will be possible in these areas.

LAT...LON 3451 8177 3464 8193 3485 8176 3466 8152
TIME...MOT...LOC 1856Z 223DEG 9KT 3463 8179

KRENTZ

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
347 PM EDT Mon Jul 12 2021

SCZ006>008-010>012-122015-
Cherokee SC-Laurens SC-Anderson SC-Abbeville SC-Spartanburg SC-
Greater Greenville SC-
347 PM EDT Mon Jul 12 2021

...HEAVY RAIN SHOWERS WITH EMBEDDED THUNDERSTORMS WILL IMPACT
NORTHWESTERN LAURENS...SOUTHEASTERN GREENVILLE...CENTRAL
SPARTANBURG...EAST CENTRAL ANDERSON... NORTHWESTERN CHEROKEE AND
NORTHEASTERN ABBEVILLE COUNTIES UNTIL 415 PM EDT...

At 345 PM EDT, Doppler radar indicated heavy rain showers with
occasional thunderstorms along a line extending from 7 miles
northeast of Spartanburg to 14 miles east of Anderson, and moving
northeast at 25 mph.

Locations to be impacted include...
Spartanburg, Gaffney, Fountain Inn, Woodruff, Honea Path, Cowpens,
Mayo, Roebuck, Gray Court and Pacolet Mills.

Wind gusts up to 40 mph, pea size hail and very heavy rainfall rates
up to 2 inches per hour will be possible in these areas.

LAT...LON 3449 8247 3518 8176 3518 8168 3512 8153
      3438 8230
TIME...MOT...LOC 1945Z 220DEG 22KT 3503 8187 3452 8239

KRENTZ

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
403 PM EDT MON JUL 12 2021

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

0215 PM     TSTM WND DMG     3 NW LOWESVILLE         35.46N 81.04W
07/09/2021                   LINCOLN            NC   EMERGENCY MNGR

            EMERGENCY MNGR REPORTED TREES DOWN ON A HOUSE ON N
            INGLESIDE FARM RD.

&&

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
407 PM EDT Mon Jul 12 2021

SCZ013-014-122030-
Union SC-Chester SC-
407 PM EDT Mon Jul 12 2021

...A STRONG THUNDERSTORM WILL IMPACT SOUTHWESTERN CHESTER AND
SOUTHEASTERN UNION COUNTIES UNTIL 430 PM EDT...

At 407 PM EDT, Doppler radar was tracking a strong thunderstorm 16
miles northwest of VC Summer Nuclear Station, or 6 miles south of
Carlisle, moving northeast at 20 mph.

Locations to be impacted include...
Carlisle, Tuckertown and Leeds.

Wind gusts up to 40 mph, pea size hail and very heavy rainfall rates
up to 2 inches per hour will be possible in these areas.

LAT...LON 3450 8159 3474 8144 3458 8118 3456 8121
      3457 8142 3453 8143 3450 8142 3449 8143
      3450 8144 3449 8144 3449 8149 3445 8153
TIME...MOT...LOC 2007Z 215DEG 12KT 3450 8146

KRENTZ