Special Weather Statement, NWS Greenville-Spartanburg, SC

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
229 PM EDT Thu Jul 8 2021

.SYNOPSIS...
Tropical Cyclone Elsa will move northeast from the Piedmont of North
Carolina across the Delmarva Peninsula tonight. Moisture will return
from the west through Friday along a weak cold front. An active mid-
summertime pattern, with a chance of showers and thunderstorms each
afternoon, will develop this weekend and continue through next week.

&&

.NEAR TERM /THROUGH FRIDAY/...
As of 215 pm EDT: The center of circulation of Tropical Storm Elsa
is evident on radar, satellite imagery, and surface observations
over the NC central Piedmont just west of I-95 early this afternoon.
The system will move away to the northeast, crossing the Delmarva
Peninsula tonight. Increasing insolation west of the departing
system is permitting SBCAPE values to bubble back up to near 1500-
2000 J/kg from the southwest, and mid to late afternoon triggering
off the mountains and with a passing weak H5 vorticity lobe aloft
will permit coverage to expand again east of the mountains. Profiles
are quite warm and moist, and DCAPE is limited, and this will limit
the potential for severe thunderstorms. Relatively solid scattered
coverage will be advertised through late day with the resurgent
activity already developing across the foothlls.

The late day convection will wane through the evening hours, but
cannot rule out isolated to scattered showers in westerly flow
across the mountains tonight, especially near the Tennessee border
in the best upslope. Fog may develop in areas that experience decent
overnight radiation, and also in the southwest mountain valleys.
Minimum temperatures will be near normal.

The upper flow will flatten out a bit through Friday. However, a
surface front will lay over into the southern Appalachians. Pre-
frontal convection from the overnight hours may cross the southern
Appalachians in the morning, when instability will be low. However,
as the activity moves east through the day, it will encounter better
daytime instability across the foothills and especially the
Piedmont. In addition, redevelopment may also occur along the weak
frontal boundary later in the day. This should lead to solid chance
PoPs across the region again on Friday afternoon, especially the
Piedmont. Anticipate near climo maximum temperatures as well.

&&

.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
As of 155 PM EDT Thursday: The weak front moves from Friday stalls
near the area on Saturday then moves to our north on Sunday. The
weak forcing and continued low level moisture will keep the
atmosphere unstable with mainly diurnal convection favoring the
mountains on Saturday then all areas for Sunday. Instability
increases to the moderate range but shear remains on the weak side.
PW values will be on the moist side. Can't rule out an isolated
strong to severe storm or isolated heavy rainfall are either day.
Highs will be near to slightly above normal Saturday then drop a
degree or so Sunday. Muggy conditions will remain in place both
days.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
As of 225 PM EDT Thursday: A more typical summertime patter returns
for the medium range with a Subtropical Bermuda high developing
surface and aloft. That said, an upper low forms over the Central
CONUS Monday, opens up on Tuesday, then moves across the Great Lakes
Wednesday and Thursday weakening the ridge. This will increase the
moisture flow, and resultant instability, across the area. Still
expect mainly diurnal convection, but PoP values will be higher than
usual for a Bermuda high pattern, especially on Monday and possibly
Tuesday. Highs start out a little below normal on Monday then rise
to near or slightly above normal by Thursday.

&&

.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
At KCLT and elsewhere: The center of the TS Elsa circulation is
moving through the central Piedmont of NC this afternoon and impacts
across the terminal forecast area are diminishing. However, with
improving breaks in the clouds, instability is returning and this
will permit scattered showers and thunderstorms to redevelop around
the region, with associated MVFR restrictions. Any lingering gusts
should be less than 20 kt this afternoon, and winds will steadily
adjust toward westerly, with southwest flow by evening across the
Upstate TAF sites. Will TEMPO in the TSRA late day at the northern
tier TAF sites and also KGSP, but keep just VCTS at KAND and KGMU.
Anticipate mainly VFR conditions overnight, but with fog and low
cloud potential in the mountain valleys. Also, foothill and Piedmont
sites could see fog if the mid/high clouds thin or diminish quickly
enough. For now, will feature MVFR fog at KAVL and KHKY. PROB30 TSRA
chances return with moisture ahead of a weak cold front on Friday,
especially in the afternoon for KCLT. Flow may vary from WSW to WNW
east of the mountains, but with speeds mostly below 10 kt on Fri.

Outlook: An unsettled pattern, with mainly diurnal convection and
morning stratus/fog, is expected to persist through the weekend and
into early next week.

Confidence Table...

            18-24Z        00-06Z        06-12Z        12-18Z
KCLT       High  92%     High 100%     High 100%     High 100%
KGSP       High 100%     High 100%     High  87%     High 100%
KAVL       High 100%     High  95%     Low   36%     High  93%
KHKY       High  95%     High 100%     Med   78%     High 100%
KGMU       High 100%     High 100%     High  87%     High 100%
KAND       High 100%     High 100%     High  87%     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...RWH
NEAR TERM...HG
SHORT TERM...RWH
LONG TERM...RWH
AVIATION...HG

Hazardous Weather Outlook
National Weather Service Greenville-Spartanburg SC
1148 AM EDT Thu Jul 8 2021

GAZ010-017-018-026-028-029-NCZ033-035>037-048>053-056>059-062>065-
068>072-082-501>510-SCZ001>014-019-091600-
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-
1148 AM EDT Thu Jul 8 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 showers and thunderstorms will develop across the region
this afternoon and evening. The main threats with any thunderstorms
that form will be cloud-to-ground lightning and locally heavy
rainfall.

.DAYS TWO THROUGH SEVEN...Friday through Wednesday.

No hazardous weather is expected at this time.

.SPOTTER INFORMATION STATEMENT...

None.

HG

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
413 PM EDT Thu Jul 8 2021

SCZ003-006-082045-
Greenville Mountains SC-Greater Greenville SC-
413 PM EDT Thu Jul 8 2021

...A STRONG THUNDERSTORM WILL IMPACT NORTH CENTRAL GREENVILLE COUNTY
UNTIL 445 PM EDT...

At 412 PM EDT, Doppler radar was tracking a strong thunderstorm 14
miles northwest of Greenville Downtown, or over Slater-Marietta,
moving southeast at 10 mph.

Locations to be impacted include...
Travelers Rest, Slater-Marietta, Tigerville, Pleasant Ridge Park and
Cleveland.

Wind gusts up to 40 mph and half inch hail will be possible in these
areas.

LAT...LON 3504 8258 3510 8255 3506 8234 3494 8243
TIME...MOT...LOC 2012Z 298DEG 9KT 3504 8249

LANE