Special Weather Statement, NWS Greenville-Spartanburg, SC

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
251 PM EDT Sun Aug 2 2020

.SYNOPSIS...
Rain chances increase across the region into Monday night as
tropical moisture begins to interact with a stalling front, ahead of
Tropical Storm Isaias.  The storm will pass near the Georgia and
Carolina coasts Monday through early Tuesday, enhancing our risk of
heavy rainfall and isolated flooding.

&&

.NEAR TERM /THROUGH MONDAY/...
As of 230 pm EDT: Through sunset, coincident with the axis of the
more robust updraft helicity, scattered, locally severe thunderstorms
capable of damaging wind gusts will develop across Upstate SC and
into the North Carolina foothills.  Diurnal lessening and/or
dissipation of deeper convection is expect as the evening wears on,
but overnight, within the developing favorable upper jet
circulation/divergence and llvl theta-e ridge numerous showers and
embedded tstms should redevelop in the mtns/fthls.  At this point,
despite the varying magnitude of model late night convective
response and orientation, enough solutions are focusing on the
Northern NC Blue Ridge where the residence time of tropical showers
and storms will be the longest, perhaps running into Monday evening.
Based on this, a Flash Flood Watch will be issued for this area, and
successive shifts can monitor for any expansion if needed. Within
broadening plume of tropical moisture will maintain going trend of
pops ramping up to categorical throughout Monday, although there
exists only a low end probability that GSP's far eastern zones will
see anything more than the onset of breezy conditions by sunset on
Monday.

&&

.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
As of 250 PM Sunday: Tropical storm Isaias will be passing by to our
east Monday night and moving away from the area Tuesday. Expect
widespread precipitation will be ongoing during the evening then
tapering off quickly from west to east overnight. Heavy rainfall may
still be ongoing as well, but should follow similar pattern and
taper off quickly overnight. Flash Flood Watch will remain in effect
Monday night as a result. Gusty winds will be possible Monday night
as the cyclone moves northward. However, wind speeds should be well
below advisory level. Still, a few trees could fall given the
rainfall expected.

Isolated to scattered convection will linger Tuesday but significant
heavy rainfall is not expected. Some low end gusts will be possible
as well, but should be lower than Monday night. Highs will be a
couple of degrees below normal.

Expect a return to scattered diurnal convection on Wednesday. Highs
will back to around normal.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
As of 1250 PM Sunday: Starting Wed evening with a closed upper low
over Quebec which will move east to the Canadian maritimes by
Friday. The upper trough remains over the eastern half of the CONUS
at least early in this forecast period.  A moist low level flow will
aid in the convective development late each day. The axis of the
upper trough on both the GFS and ECMWF on Wed night will be over the
Mississippi Valley. This axis shifts to the East Coast by Sunday.
There is a notable difference on Day 7 in that the EC maintains the
trough over the East Coast into early next week while the GFS begins
replacing the East Coast trough with a ridge.  Models are in
agreement that the more active day may be on Sunday as a significant
shortwave reaches our region. Temperatures will be near normal.

&&

.AVIATION /19Z SUNDAY THROUGH FRIDAY/...
At KCLT and Elsewhere: A pretty typical summertime afternoon within
the warm sector featuring sswly sfc flow with the chance of some low
amplitude wind gusts.  Sct-bkn vfr lvl cu will continue develop into
numerous tstms as the afternoon wears on and tempo for tsra will be
carried for all terminal locations until sunset.  With diurnal
lessening/dissipation of the deep convective cvrg this evening, most
of the FA will feature just varying degrees of debris clouds until
forcing returns overnight, where numerous showers and a few
thunderstorms are expected to redevelop in and close to the higher
terrain.  For the daytime hours on Monday, expect deteriorating
flight conditions and as scattered outer rain bands encroach the
piedmont well downstream of tropical system.

Outlook: Shower and thunderstorm coverage will linger into Monday
night between a stalled mountain front and within the tropical
moisture. Daily rounds of diurnal convection will likely continue
well into late week, even with the tropical system pulling away to
the northeast.

Confidence Table...

            19-01Z        01-07Z        07-13Z        13-18Z
KCLT       High 100%     High 100%     High  83%     High  89%
KGSP       High 100%     High 100%     High  88%     High  88%
KAVL       High 100%     High  96%     Low   48%     Med   76%
KHKY       High 100%     High 100%     Med   69%     High  84%
KGMU       High 100%     High 100%     High  86%     High  86%
KAND       High 100%     High 100%     High 100%     High  85%

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...Flash Flood Watch from 2 AM EDT Monday through Tuesday morning
     for NCZ033-049-050-501>506.
SC...None.

&&

SYNOPSIS...DEO
NEAR TERM...CSH
SHORT TERM...RWH
LONG TERM...DEO/08
AVIATION...CSH

Hazardous Weather Outlook
National Weather Service Greenville-Spartanburg SC
303 PM EDT Sun Aug 2 2020

GAZ010-017-018-026-028-029-NCZ035>037-048-051>053-056>059-062>065-
068>072-082-507>510-SCZ001>014-019-031915-
Rabun-Habersham-Stephens-Franklin-Hart-Elbert-Alexander-Iredell-
Davie-Madison-Swain-Haywood-Buncombe-Catawba-Rowan-Graham-
Northern Jackson-Macon-Southern Jackson-Transylvania-Henderson-
Cleveland-Lincoln-Gaston-Mecklenburg-Cabarrus-Union NC-
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-
303 PM EDT Sun Aug 2 2020

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

.DAY ONE...Tonight.

Scattered thunderstorms will continue into the evening. Any
thunderstorms that develop will produce gusty winds, locally heavy
rainfall, and dangerous cloud-to-ground lightning. One or two
thunderstorms may become severe late today, with damaging wind gusts
the primary threat.

.DAYS TWO THROUGH SEVEN...Monday through Saturday.

Showers and thunderstorms will increase in coverage during the day
Monday, continuing to produce locally heavy rainfall. Isolated flash
flooding may occur late Monday. As Tropical Storm Isaias makes its
nearest pass to our region Monday night into early Tuesday, breezy
and occasionally gusty winds may develop. A few trees could fall in
areas where soils are saturated by the heavy rainfall. Isaias could
bring additional precipitation Monday night. Flooding may become an
increasing concern in areas that receive multiple rounds of heavy
rainfall.

.SPOTTER INFORMATION STATEMENT...

None.

NCZ033-049-050-501>506-031915-
Avery-Yancey-Mitchell-Caldwell Mountains-Greater Caldwell-
Burke Mountains-Greater Burke-McDowell Mountains-Eastern McDowell-
303 PM EDT Sun Aug 2 2020

...FLASH FLOOD WATCH IN EFFECT FROM 2 AM EDT MONDAY THROUGH TUESDAY
MORNING...

This Hazardous Weather Outlook is for western North Carolina.

.DAY ONE...Tonight.

Please listen to NOAA Weather Radio or go to weather.gov on the
Internet for more information about the following hazards.

   Flash Flood Watch.

Scattered thunderstorms will continue across the area through the
evening. Any thunderstorms that develop will produce gusty winds,
locally heavy rainfall, and dangerous cloud-to-ground lightning. A
few thunderstorms may become severe late today, with damaging wind
gusts the primary threat.

.DAYS TWO THROUGH SEVEN...Monday through Saturday.

Please listen to NOAA Weather Radio or go to weather.gov on the
Internet for more information about the following hazards.

   Flash Flood Watch.

.SPOTTER INFORMATION STATEMENT...

None.

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
349 PM EDT Sun Aug 2 2020

NCZ035-036-022015-
Iredell NC-Alexander NC-
349 PM EDT Sun Aug 2 2020

...A STRONG THUNDERSTORM WILL IMPACT SOUTHEASTERN ALEXANDER AND
NORTHWESTERN IREDELL COUNTIES UNTIL 415 PM EDT...

At 349 PM EDT, Doppler radar was tracking a strong thunderstorm 8
miles east of Taylorsville, or near Stony Point, moving northeast at
20 mph.

Locations to be impacted include...
Taylorsville, Stony Point, Love Valley, Hiddenite and Scotts.

Wind gusts up to 45 mph and half inch hail will be possible in these
areas.

LAT...LON 3587 8086 3582 8109 3593 8117 3606 8091
      3606 8089
TIME...MOT...LOC 1949Z 243DEG 15KT 3589 8104

LANE

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
353 PM EDT Sun Aug 2 2020

NCZ068-508-022030-
Greater Rutherford NC-Cleveland NC-
353 PM EDT Sun Aug 2 2020

...A STRONG THUNDERSTORM WILL IMPACT EAST CENTRAL RUTHERFORD AND
NORTHWESTERN CLEVELAND COUNTIES UNTIL 430 PM EDT...

At 352 PM EDT, Doppler radar was tracking a strong thunderstorm 8
miles east of Forest City, or near Ellenboro, moving northeast at 30
mph.

Locations to be impacted include...
Forest City, Lawndale, Polkville, Ellenboro, Bostic, Casar,
Kingstown, Lattimore and Caroleen.

Wind gusts up to 45 mph and half inch hail will be possible in these
areas.

LAT...LON 3528 8180 3536 8187 3552 8161 3536 8153
TIME...MOT...LOC 1952Z 243DEG 25KT 3538 8172

LANE

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
357 PM EDT Sun Aug 2 2020

NCZ053-022030-
Buncombe NC-
357 PM EDT Sun Aug 2 2020

...A STRONG THUNDERSTORM WILL IMPACT CENTRAL BUNCOMBE COUNTY UNTIL
430 PM EDT...

At 356 PM EDT, Doppler radar was tracking a strong thunderstorm near
Asheville, moving northeast at 25 mph.

Locations to be impacted include...
Downtown Asheville, East Asheville, Black Mountain, Swannanoa,
Biltmore Forest, Warren Wilson College, and Fairview.

Wind gusts up to 45 mph and pea size hail will be possible in these
areas.

LAT...LON 3574 8238 3562 8227 3560 8229 3548 8253
      3555 8260
TIME...MOT...LOC 1956Z 227DEG 22KT 3557 8249

LANE

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
400 PM EDT Sun Aug 2 2020

SCZ011-019-022030-
Abbeville SC-Greenwood SC-
400 PM EDT Sun Aug 2 2020

...A STRONG THUNDERSTORM WILL IMPACT EAST CENTRAL ABBEVILLE AND
NORTHWESTERN GREENWOOD COUNTIES UNTIL 430 PM EDT...

At 400 PM EDT, Doppler radar was tracking a strong thunderstorm 4
miles northwest of Greenwood, or 4 miles south of Cokesbury, moving
northeast at 10 mph.

Locations to be impacted include...
Greenwood, Cokesbury, Hodges and Coronaca.

Wind gusts up to 45 mph and pea size hail will be possible in these
areas.

LAT...LON 3416 8224 3422 8232 3434 8219 3422 8208
TIME...MOT...LOC 2000Z 237DEG 11KT 3423 8222

LANE

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
406 PM EDT Sun Aug 2 2020

SCZ006-022030-
Greater Greenville SC-
406 PM EDT Sun Aug 2 2020

...A STRONG THUNDERSTORM WILL IMPACT SOUTHEASTERN GREENVILLE COUNTY
UNTIL 430 PM EDT...

At 406 PM EDT, Doppler radar was tracking a strong thunderstorm 10
miles south of Greenville Downtown, or near Donaldson Center, moving
northeast at 15 mph.

Locations to be impacted include...
Mauldin, Simpsonville, Donaldson Center, Piedmont, Greenville
Eastside, and Fountain Inn.

Wind gusts up to 45 mph and half inch hail will be possible in these
areas.

LAT...LON 3467 8246 3471 8246 3484 8233 3471 8219
      3462 8240
TIME...MOT...LOC 2006Z 227DEG 11KT 3470 8239

LANE

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
421 PM EDT Sun Aug 2 2020

NCZ036-022045-
Iredell NC-
421 PM EDT Sun Aug 2 2020

...A STRONG THUNDERSTORM WILL IMPACT NORTHEASTERN IREDELL COUNTY
UNTIL 445 PM EDT...

At 421 PM EDT, Doppler radar was tracking a strong thunderstorm 12
miles southwest of Yadkinville, or over Harmony, moving northeast at
30 mph.

Locations to be impacted include...
Harmony, Turnersburg and Olin.

Wind gusts up to 45 mph and pea size hail will be possible in these
areas.

LAT...LON 3605 8069 3600 8069 3600 8070 3592 8070
      3590 8087 3598 8092 3605 8071
TIME...MOT...LOC 2021Z 247DEG 27KT 3597 8077

LANE