Special Weather Statement, NWS Greenville-Spartanburg, SC

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
238 PM EDT Wed Sep 1 2021

.SYNOPSIS...
Continental high pressure is expected to provide fair skies and
seasonable temperatures Thursday through Saturday. A long-wave
trough may settle into the region by Sunday and support a series of
weak fronts through early next week.

&&

.NEAR TERM /THROUGH THURSDAY/...
As of 200 PM EDT Wednesday: The center of Ida has launched
into the Mid-Atlantic this afternoon. The Remnants of Ida has
presented us with a leftover surface trough that is draped over
the Piedmont and foothills. Light precipitation has slowly pushed
into portions of the Piedmont and has the potential to develop
into a few thunderstorms as we enter the peak heating of the day
in which destabilization has allowed SBCAPE values to range between
1000-1500 J/kg everywhere outside of the High Country. The surface
trough will promptly keep winds from the SW and in turn, could
help initiate scattered showers and thunderstorms in portions of
the Upstate and NC Piedmont later this afternoon, which is being
depicted from the CAMs, but should wane off fairly quickly by sunset
as drier NW flow begins to filter in. NW-ly upslope showers should
continue along the TN border through the evening before gradually
diminishing early overnight as the drier air overrides the moisture
needed to sustain shower development. Due to the lingering cloud
cover and precipitation, high temperatures will be a category or
two below normal for much of the CFWA today.

Outside of low stratus/fog developing in the major mountain valleys,
expect most locations to remain dry, while clouds continue to
scatter out and eventually dissipate fully by the mid-morning hours
Thursday. With weak, dry CAA working into the CFWA, low temperatures
should be a tick below normal. With the upper trough axis exiting
to the east and a broad surface high hovering over the Upper Great
Lakes on Thursday, winds will retain a northerly component and dry
air will continue entraining into the area. Partly to mostly sunny
skies will prevail throughout the day, but temperatures will be a
category warmer Thursday compared to Wednesday due to rising heights
from a strengthening upper ridge to the west, over the south-central
CONUS and deep insolation at the surface for most of the day.

&&

.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...
As of 200 pm EDT Wednesday: An upper-level high pressure ridge
will extend from the southern Plains across the southeastern U.S.
Thursday night into Friday. Meanwhile, sprawling surface high
pressure will be in place from the Great lakes to the southeast.
This setup will maintain dry and cooler profiles across the forecast
area. The improved radiating conditions will permit minimum
temperatures Friday morning to settle out on the cool side of
guidance.

Weak shortwaves may dive southeast over the retreating southern
ridge on Friday night, but with little to no attendant moisture. The
airmass will then begin to modify on Saturday, but not enough at
this point to carry the isolated, diurnal shallow convection
indicated on a few numerical models. Maximum temperatures will
recover a couple of degrees over Friday values.

&&

.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
As of 230 pm EDT Wednesday: The retreating southeast ridge will
continue to break down through the latter half of the weekend as
heights fall sharply across the Great Lakes and the Midwest. The
resulting, deepening trough axis will push a cold front southeast
into the region Sunday through Sunday night, and pre-frontal
moisture could arrive as early as Saturday night. The moisture band
still looks fairly narrow, and instability is unimpressive, so will
cap PoPs at chance mountains/slight chance lower Piedmont for the
peak Sunday/Sunday night period when upper jet energy will be a bit
better.

The eastern trough will get reinforced Monday through Wednesday.
Brief drying may occur on Monday if the boundary settles just to the
southeast. Additional frontal zone moisture should arrive in the
Tuesday to Wednesday period, with uncertain timing at the current
projection. Will feature very low-end PoPs, but with above climo
temperatures through the period.

&&

.AVIATION /19Z WEDNESDAY THROUGH MONDAY/...
At KCLT and elsewhere: Precipitation continues to push across the
area and a VCSH/VCTS has been included everywhere, but KAND. Winds
will continue to come out of the W/SW over the next few hours due
to an established surface trough over the CFWA, with the exception
of KAVL. Winds will turn to the NW during the evening hours as
the Remnants of Ida continues to lift to the northeast and the
surface trough fades. This is reflected in the TAFs, with VCSH
taken out around the same time as the drier air filters in. A
TEMPO for -TSRA in KCLT through 00Z Thursday due to the better
instability and has the best shot for thunderstorm development to
occur during the peak heating of the day. Precipitation should wane
off after sunrise and VFR conditions will prevail for all TAF sites
through the rest of the period, except for KAVL. KAVL could get
involved with the low stratus/fog over the major mountain valleys,
but an up-valley wind should hinder KAVL from getting below MVFR
vsbys/cigs. Dry N/NE wind and partly to mostly cloudy skies will
lead to a quiet TAF period for all terminals.

Outlook: Significantly drier air will continue to overspread
the area through Friday, resulting in dry/calm conditions
through at least Saturday. A cold front could bring scattered
convection, mainly to the mountains late Sunday.

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...None.
NC...None.
SC...None.

&&

SYNOPSIS...DEO
NEAR TERM...CAC
SHORT TERM...HG
LONG TERM...HG
AVIATION...CAC

Hazardous Weather Outlook
National Weather Service Greenville-Spartanburg SC
342 PM EDT Wed Sep 1 2021

NCZ035>037-056-057-068>072-082-502-504-506>510-SCZ002-003-005>014-
019-021945-
Alexander-Iredell-Davie-Catawba-Rowan-Cleveland-Lincoln-Gaston-
Mecklenburg-Cabarrus-Union NC-Greater Caldwell-Greater Burke-
Eastern McDowell-Rutherford Mountains-Greater Rutherford-
Polk Mountains-Eastern Polk-Pickens Mountains-Greenville Mountains-
Greater Pickens-Greater Greenville-Spartanburg-Cherokee-York-
Anderson-Abbeville-Laurens-Union SC-Chester-Greenwood-
342 PM EDT Wed Sep 1 2021

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

.DAY ONE...This afternoon and tonight.

Isolated to widely scattered thunderstorms will continue through
early this evening. A few storms could be strong with cloud-to-
ground lightning and damaging wind. Activity should come to an end
this evening as daytime heating dies off.

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

Hazardous weather is not expected at this time.

.SPOTTER INFORMATION STATEMENT...

None.

GAZ010-017-018-026-028-029-NCZ033-048>053-058-059-062>065-501-503-
505-SCZ001-004-021945-
Rabun-Habersham-Stephens-Franklin-Hart-Elbert-Avery-Madison-Yancey-
Mitchell-Swain-Haywood-Buncombe-Graham-Northern Jackson-Macon-
Southern Jackson-Transylvania-Henderson-Caldwell Mountains-
Burke Mountains-McDowell Mountains-Oconee Mountains-Greater Oconee-
342 PM EDT Wed Sep 1 2021

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

.DAY ONE...This afternoon and tonight.

No hazardous weather is expected at this time.

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

No hazardous weather is expected at this time.

.SPOTTER INFORMATION STATEMENT...

None.

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
412 PM EDT Wed Sep 1 2021

NCZ036-056-069>071-012045-
Gaston NC-Iredell NC-Lincoln NC-Mecklenburg NC-Catawba NC-
412 PM EDT Wed Sep 1 2021

...THUNDERSTORMS WITH TORRENTIAL RAINFALL WILL IMPACT SOUTHEASTERN
CATAWBA...LINCOLN...SOUTHEASTERN IREDELL...NORTHWESTERN MECKLENBURG
AND NORTHERN GASTON COUNTIES UNTIL 445 PM EDT...

At 412 PM EDT, Doppler radar indicated thunderstorms with torrential
rainfall along a line extending from 10 miles southeast of Newton to
3 miles southwest of Lincolnton, and moving east at 30 mph.

Locations to be impacted include...
Huntersville, Lincolnton, Cornelius, Mooresville, Davidson, Westport,
High Shoals, Lake Norman, Boger City and Iron Station.

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 3551 8078 3550 8079 3543 8081 3541 8083
      3539 8087 3534 8099 3542 8146 3558 8118
      3560 8075 3551 8075
TIME...MOT...LOC 2012Z 269DEG 25KT 3554 8110 3544 8128

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