Special Weather Statement, NWS Greenville-Spartanburg, SC

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
1004 AM EDT Sun Aug 6 2023

.SYNOPSIS...
A warm front lifts north across the area today before a cold front
tracks out of the west on Monday. These two systems will act to
increase shower and thunderstorm chances, as well as humidity.
Strong to severe storms will be possible each afternoon and evening.
Heat indices may climb into the triple digits east of the mountains,
especially on Monday. The front looks to stall just south and east
of the forecast area Tuesday into Wednesday leading to drier
conditions. Shower and thunderstorm chances return Thursday.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 945 AM EDT: Weak shortwave over SE TN continues to drive
disorganized/weak convection, with the leading edge of shower
activity now entering the Smokies. Recent radar trends suggest
the rain shield may struggle to push east of the mountain spine,
but expectation is that the shortwave will persist and help
enhance convective initiation over the mountains by midday as we
destabilize. Made some updates to PoPs in the first few hours,
but made no changes to values at peak heating/coverage this
aftn. Despite the short wave moving in, bulk and effective shear
remain on the weak side. There will be some DCAPE and surface
delta theta e, but again, not especially high. The CAM guidance
still suggests convection to become more organized as it moves out
of the mountains and across the foothills and Piedmont later in
the afternoon. A few of the storms could be severe, with damaging
winds the main threat but some large hail also possible. SPC trimmed
us out of the Slight Risk mainly on expectation that the upstream
MCS activity will track more southward. They did maintain Marginal
for almost the entire CWA, and that seems reasonable. Highs will
be near normal with dew points around 70 degrees creating Heat
Index values around 100 degrees, mainly along and near the Upper
Savannah River Valley.

The initial round of convection will move east of the area by early
evening. The CAMs show the potential for an MCS to approach the area
overnight. However, they disagree on the location, moving out of KY
into NE TN, or along the TN/AL/GA borders. That said, the do agree
that the convection should weaken and mostly dissipate by the time
it reaches our area. Lows will be a couple of degrees above normal.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
As of 330 AM EDT Sunday: Severe weather on Monday continues to look
likely across the entire forecast area as a cold front approaches
out of the west. This front will lead to a few rounds of storms
Monday into Monday night. 00Z global models and CAMs show SBCAPE
values ranging from 2000-3500 J/kg and MLCAPE values ranging from
2000-4000 J/kg across the western Carolinas and northeast Georgia.
This instability combined with guidance showing 0-6 km Bulk Shear
values ranging from 30-40 kts, should allow numerous severe storms
to develop across the CWA Monday afternoon into late Monday evening.
SPC upgraded the entire forecast area to an Enhanced Risk for severe
storms, which makes sense, as CAMs depict a line of storms
developing a bowing segment across mainly NE GA and the SC Upstate
by the late afternoon/early evening hours. Damaging winds will be
the main threat as models show DCAPE values ranging from 1000-1500
J/kg across the CWA. The secondary threat will be large hail,
especially with any discrete cells that develop. Models are split
regarding just how much 0-1 km shear will be available, but guidance
generally shows values up to 20 kts possible. So, there will be an
isolated tornado threat with any discrete cells that develop as well
as a QLCS tornado threat within the MCS that is expected to develop
late Monday. In addition to the severe weather threat, there will be
the potential for localized hydro issues with any training
convection. Heat and humidity will climb ahead of the FROPA Monday
afternoon, leading to highs around 2-5 degrees above climo. Heat
indices may climb into the low 100s east of the mountains, with the
Upper Savannah River Valley potentially seeing heat indices near
advisory criteria. However, heat indices may be limited somewhat by
both convection and cloud cover.

The FROPA will push across the CWA overnight Monday into Tuesday.
This may keep convection going into part of the overnight hours on
Monday, mainly across the southern half of the CWA per the 00Z CAMs.
Lows Monday night should be around 3-5 degrees above climo thanks to
lingering convection and cloud cover. The FROPA should push south
and east of the CWA by Tuesday evening. Some NW flow rain showers
may develop along the NC/TN border behind the FROPA, so have chance
PoPs across these zones through Tuesday afternoon. Humidity and
temps will decrease behind the FROPA on Tuesday leading to a drier
and more pleasant day. Highs should be near normal across the
southern zones and a few degrees below climo across the northern
zones. Lows Tuesday night should be near climo thanks to decreasing
cloud cover.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
As of 345 AM EDT Sunday: Upper troughing remains over the eastern US
through the long term period. At the sfc, high pressure builds in
briefly on Wednesday leading to mostly dry conditions. Wednesday
night into Thursday more active weather returns as 00Z global models
continue to show a vigorous shortwave tracking over the CWA. Thus,
have PoPs ramping up across the area as shower and thunderstorm
chances are expected to return during this timeframe. Models show 30-
40 kts of 0-6 km Bulk Shear and SBCAPE values from 1500-2000 J/kg
across the western Carolinas and northeast Georgia Thursday
afternoon and early evening. So, there could be the potential for a
few strong to severe storms to develop. Confidence on the rest of
the long term remains low as models are not in great agreement
regarding the overall pattern/convective potential. However, with
unsettled weather looking to stick around, maintained chance PoPs
heading into the weekend. Lows will be a few degrees above climo
through the period. Highs will be near climo Wednesday, becoming a
few degrees below climo Thursday thanks to cloud cover and
convection. Highs return to near normal values Friday onward.

&&

.AVIATION /14Z SUNDAY THROUGH THURSDAY/...
At KCLT and elsewhere: VFR this morning with increasing cirrus and
then cu and/or stratocu by late morning. A few showers may move near
KAVL this morning as well. Still expect a line of convection to move
across the area this afternoon so converted the PROB30s to TEMPOs
based on latest CAM guidance timing. S wind this morning picks up
speed from the SW for the afternoon before diminishing during the
evening. Low VFR may linger or return overnight with fog expected at
KAVL and KHKY, and possibly elsewhere.

Outlook: Similar conditions continue Monday as a cold front
arrives from the northwest. Thunderstorms, some severe, will be
numerous. The boundary could stall just southeast of the area
through the end of the work week with isolated to low end scattered
diurnal convection. Daybreak restrictions will be possible each day,
especially in the mountain river valleys.

&&

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

&&

SYNOPSIS...AR
NEAR TERM...RWH/Wimberley
SHORT TERM...AR
LONG TERM...AR
AVIATION...RWH

Hazardous Weather Outlook
National Weather Service Greenville-Spartanburg SC
413 AM EDT Sun Aug 6 2023

GAZ010-017-018-026-028-029-NCZ033-035>037-048>053-056>059-062>065-
068>072-082-501>510-SCZ008>014-019-101>109-070815-
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-Cherokee-York-
Anderson-Abbeville-Laurens-Union SC-Chester-Greenwood-
Oconee Mountains-Pickens Mountains-Greenville Mountains-
Greater Oconee-Greater Pickens-Central Greenville-
Southern Greenville-Northern Spartanburg-Southern Spartanburg-
413 AM EDT Sun Aug 6 2023

This Hazardous Weather Outlook is for northeast Georgia, western
North Carolina and the Upstate of South Carolina.

.DAY ONE...Today and tonight.

Scattered thunderstorms will develop across the forecast area this
afternoon and early evening. A few may become strong to severe. The
main potential hazards with any storms that become severe are
damaging winds and large hail. Localized flash flooding may occur
with slow moving storms as well as storms that repeatedly track over
the same location. Cloud-to-ground lightning, gusty winds, and heavy
downpours can be expected with any thunderstorms that develop.
Additionally, heat indices may reach the lower 100s across the
western South Carolina Upstate and portions of northeast Georgia this
afternoon.

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

Severe storms are likely Monday afternoon and evening across the
forecast area. Damaging winds are the main threat, but large hail
and isolated tornadoes will also be possible. Cloud-to-ground
lightning, locally heavy rainfall, and gusty winds are expected with
any thunderstorms that develop. Additionally, heat indices may reach
the lower 100s east of the mountains Monday afternoon.

.SPOTTER INFORMATION STATEMENT...

Spotters are requested to forward any reports of large hail,
damaging winds, tornadoes, or flash flooding to our office.

AR

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
108 PM EDT Sun Aug 6 2023

SCZ103-106-061745-
Central Greenville SC-Greenville Mountains SC-
108 PM EDT Sun Aug 6 2023

...A strong thunderstorm will impact portions of northeastern
Greenville County through 145 PM EDT...

At 108 PM EDT, Doppler radar was tracking a strong thunderstorm 14
miles north of Greenville Downtown, or near Slater-Marietta, moving
east at 15 mph.

HAZARD...Wind gusts up to 50 mph.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects.

Locations impacted include...
Travelers Rest, Slater-Marietta, Tigerville, Pleasant Ridge State
Park, Furman University, Paris Mountain State Park, Gowensville,
Cleveland and Glassy Mountain.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 3492 8243 3500 8253 3501 8254 3501 8255
      3504 8258 3514 8242 3513 8222 3511 8222
TIME...MOT...LOC 1708Z 278DEG 14KT 3505 8244

MAX HAIL SIZE...0.00 IN
MAX WIND GUST...50 MPH

MPR

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
152 PM EDT Sun Aug 6 2023

NCZ056-069-504-061815-
Lincoln NC-Greater Burke NC-Catawba NC-
152 PM EDT Sun Aug 6 2023

...A strong thunderstorm will impact portions of western Catawba,
northwestern Lincoln and southeastern Burke Counties through 215 PM
EDT...

At 152 PM EDT, Doppler radar was tracking a strong thunderstorm 13
miles southeast of Morganton, or 7 miles southwest of Icard, moving
east at 30 mph.

HAZARD...Wind gusts up to 40 mph.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects.

Locations impacted include...
Hickory, Newton, Conover, Longview, Maiden, Hildebran, Mountain View,
Icard, St. Stephens and Cooksville.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 3554 8116 3555 8151 3557 8154 3556 8157
      3557 8158 3557 8160 3569 8161 3577 8122
TIME...MOT...LOC 1752Z 261DEG 25KT 3562 8151

MAX HAIL SIZE...0.00 IN
MAX WIND GUST...40 MPH

MPR

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
206 PM EDT Sun Aug 6 2023

NCZ068-508-SCZ008-061830-
Greater Rutherford NC-Cleveland NC-Cherokee SC-
206 PM EDT Sun Aug 6 2023

...A strong thunderstorm will impact portions of southeastern
Rutherford, southwestern Cleveland and northern Cherokee Counties
through 230 PM EDT...

At 205 PM EDT, Doppler radar was tracking a strong thunderstorm 9
miles south of Forest City, or 4 miles north of Cowpens National
Battlefield, moving east at 30 mph.

HAZARD...Wind gusts up to 40 mph and pea size hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects. Minor damage to outdoor objects is
         possible.

Locations impacted include...
Shelby, Boiling Springs NC, Blacksburg, Grover, Patterson Springs,
Lattimore, Mooresboro, Earl, Cowpens National Battlefield and
Cliffside.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 3511 8140 3510 8140 3510 8183 3518 8187
      3519 8189 3528 8190 3537 8144
TIME...MOT...LOC 1805Z 263DEG 26KT 3521 8180

MAX HAIL SIZE...0.25 IN
MAX WIND GUST...40 MPH

KRENTZ

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
209 PM EDT Sun Aug 6 2023

SCZ012-013-061845-
Laurens SC-Union SC-
209 PM EDT Sun Aug 6 2023

...A strong thunderstorm will impact portions of central Laurens and
west central Union Counties through 245 PM EDT...

At 208 PM EDT, Doppler radar was tracking a strong thunderstorm near
Laurens, moving east at 20 mph.

HAZARD...Wind gusts up to 40 mph and pea size hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects. Minor damage to outdoor objects is
         possible.

Locations impacted include...
Laurens, Clinton, Joanna, Gray Court, Cross Keys, Sedalia, Ora and
Kinards.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 3444 8213 3462 8211 3463 8193 3460 8191
      3459 8189 3460 8188 3458 8186 3460 8185
      3463 8184 3464 8171 3443 8173 3438 8178
TIME...MOT...LOC 1808Z 275DEG 19KT 3453 8204

MAX HAIL SIZE...0.25 IN
MAX WIND GUST...40 MPH

KRENTZ