Special Weather Statement, NWS Greenville-Spartanburg, SC

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
329 AM EDT Fri Oct 29 2021

.SYNOPSIS...
A deep low pressure system will move over the region today through
tonight. As the low pressure moves away to the east this weekend,
drying high pressure will spread back over the region on Sunday and
persist through early next week. A cold front will impact the area
middle of next week, increasing rain chances again.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 330 am EDT: Will handle lowered visibility and dense fog with
an SPS early this morning since the conditions may be temporary as
additional cloudiness spills back in from the west.

Satellite imagery continues to reveal a deep and vertically stacked
low pressure system over the middle Mississippi River Valley early
this morning. East of this system, another round of upper forcing
from a 250 mb jetlet and an upper DPVA lobe are forcing an area of
heavy showers northward across our region. This will impact
primarily the northern tier of western NC through the early morning
hours, with max rainfall values around an inch with the heaviest
downpours. Given the forward speed of the rainfall, hydrology issues
are not expected. Steepening mid-level lapse rates as drier air
wraps in aloft may lead to a rogue lightning strike or two, and
isolated thunder will be retained in the forecast through daybreak
in the NC foothill/Piedmont. Otherwise, low-level isentropic lift
will pivot north of the forecast area early this morning and the
higher PoPs will diminish from the south.

The H5 low center will then steadily migrate east toward the base of
the southern Appalachians today. This will bring a pocket of minus
21C 500 mb temps over the southern mountains. However, 850 mb
temperatures will cool from the southwest in an unusual fashion at
the same time, so lapse rates do not appear to get any steeper
through the day. Still, the proximity of the upper low and
associated spokes of forcing will permit PoPs to creep back up from
the southwest through the day, with the PoP gradient ranging from
categorical in and near the Smokies to chance over the NC Piedmont
as moisture in profiles fills back in from the west ahead of the low
center. With less precipitation for the bulk of the day, maxes
should rebound slightly into the 60s in the Piedmont, but remain
capped in the 50s foothills, with plenty of 40s in the cloudier and
wetter mountains. Chilly ridge top temperatures could cool even
further late in the day as the H5 center arrives, with profiles
suggesting snow levels falling to 5000 to 6000 feet MSL. Will thus
feature a rain/snow mix at the higher elevations of the NC mountains
late today into tonight, with light accums possible on the very
highest ridge tops.

The H5 center will then migrate northeast and steadily diminish any
lingering DPVA tonight. However, low-level westerly upslope flow
will keep shower chances going along the spine of the southern
Appalachians, with continued light snow shower chances along the
highest peaks. Expect mins in the 40s throughout, except 30s at the
higher elevations.

&&

.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
As of 300 AM Friday: The large low pressure system remains situated
over the eastern Conus at the start of the forecast period before
gradually lifting northeast and weakening late Saturday afternoon
into early Sunday morning as it tracks into the northeastern US.
Throughout the day Sunday the low pressure system will continue to
weaken as it takes a more northerly track into eastern Canada.
Sunday night what is left of the area of low pressure gets absorbed
by another large low pressure system to the west across central
Canada and the northern US. This low will keep shower chances around
Saturday, with the best chance across the western CWA. PoPs across
the western zones range from high end chance to low end likely. PoPs
for the central and eastern zones will range from a slight chance to
low end chance. Northwest flow keeps showers chances around for the
western CWA Saturday night into late Sunday morning, while the
remainder of the CWA can expect dry conditions. Wind gusts will
remain breezy across portions of the NC Piedmont, SC Upstate, and
the spine of the Appalachians Saturday. Wind gusts increase late
Saturday night into late Sunday morning, ranging from 15 to 25 mph
mainly across the mountain zones. Wind gusts are expected to relax
late Sunday night into early Monday morning. Quasi-zonal flow
develops towards the end of the forecast period with sfc high
pressure building in from the northwest. Highs Saturday will be 5 to
10 degrees below normal thanks to cloud cover. Sunday highs will be
near normal outside the mtns due to increased insolation, while
highs across the mtns are expected to remain below normal due to NW
flow keeping cloudiness around. Saturday night lows will be above
climo, becoming near climo Sunday night.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
As of 300 AM Friday: Quasi-zonal flow will be in place into early
next week with sfc high pressure continuing to extend into the
Southeast through early Wednesday. This overall pattern will lead to
dry fall like conditions through at least early next week. Upper-
level troughing returns middle of next week as a large low pressure
system tracks across eastern Canada. Once we get to late Wednesday
and beyond, models begin to diverge regarding a cold front
approaching from the west that is associated with the upper-level
trough. Both the ECMWF and GFS have the FROPA pushing into the
forecast area late Wednesday afternoon into Wednesday evening.
Meanwhile the Canadian does not have the FROPA pushing into the area
until early Thursday morning. The GFS keeps PoPs confined to the
northern CWA while the ECMWF and Canadian have PoPs across the
entire CWA. With models not in good agreement towards the end of the
period, decided to go with NBM PoPs. This leads to a slight chance
to chance of PoPs starting late Wednesday afternoon and continuing
into late Thursday. Highs Monday and Tuesday will be near or just
above climo with lows above climo. Highs Wednesday and Thursday drop
to below climo with lows near or just above climo.

&&

.AVIATION /08Z FRIDAY THROUGH TUESDAY/...
At KCLT and elsewhere: Abundant moisture near the surface, with
drying aloft through the early morning hours, appears certain to
lock most or all of the TAF sites into LIFR vsby/cig, or worse. It
may take until the northward-lifting precipitation shield, and the
associated mixing of the column, pulls north of the individual
terminal before the lower cigs/vsby are realized. The widespread
lower cigs and vsby could be variable with the encroaching mid/high
clouds from the west, but they will be slow to improve through the
morning hours, with an increase to MVFR cigs at least likely by late
morning/early afternoon. Moisture will deepen again in the column
from the west through the day as the deep, upstream H5 low center
migrates toward the southern Appalachians. Will reintroduce mainly
PROB30 SHRA for this feature, with the chances best at KAVL, second
best at the foothill sites, and lowest at KCLT. Expect southerly
winds to pick up with modest mixing this morning, with low end
southwesterly gusts possible for the afternoon hours. Lowering cigs
may start to fill back into tonight with the continued moist
boundary layer in place.

Outlook: Unsettled conditions may persist into the first half of the
weekend, especially in the mountains in continued moist westerly
flow. Drying and VFR condition will get better established later in
the weekend, with drier high pressure lingering into early next
week. KAVL will see the best chance of intermittent restrictions
through the period.

&&

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

&&

SYNOPSIS...AP/HG
NEAR TERM...HG
SHORT TERM...AP
LONG TERM...AP
AVIATION...HG

Hazardous Weather Outlook
National Weather Service Greenville-Spartanburg SC
507 AM EDT Fri Oct 29 2021

GAZ010-017-018-026-028-029-NCZ033-035>037-048>053-056>059-062>065-
068>072-082-501>510-SCZ001>014-019-300915-
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-
507 AM EDT Fri Oct 29 2021

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

.DAY ONE...Today and tonight.

Scattered showers can be expected today with isolated embedded
thunder possible at times. Main potential impacts are cloud-to-
ground lightning, brief heavy downpours, and small hail.

.DAYS TWO THROUGH SEVEN...Saturday through Thursday.

No hazardous weather is expected at this time.

.SPOTTER INFORMATION STATEMENT...

None.

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
453 AM EDT Fri Oct 29 2021

SCZ007-290930-
Spartanburg SC-
453 AM EDT Fri Oct 29 2021

...A thunderstorm with small hail will impact portions of northern
Spartanburg County through 530 AM EDT...

At 452 AM EDT, Doppler radar was tracking a thunderstorm 11 miles
west of Spartanburg, or near Wellford, moving east at 20 mph.

HAZARD...Pea size hail.

SOURCE...Radar indicated.

IMPACT...Minor damage to outdoor objects is possible.

Locations impacted include...
Spartanburg, Boiling Springs SC, Duncan, Lyman, Cowpens, Wellford,
Inman, Mayo, Chesnee and Lake Bowen.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, seek shelter inside a building until the lightning and
hail pass by.

&&

LAT...LON 3489 8215 3503 8222 3506 8222 3519 8196
      3519 8189 3518 8187 3505 8181 3504 8181
      3503 8180 3497 8176 3496 8177
TIME...MOT...LOC 0852Z 248DEG 19KT 3500 8211

MAX HAIL SIZE...0.25 IN
MAX WIND GUST...<30 MPH

HG

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
503 AM EDT Fri Oct 29 2021

SCZ007-012-013-290930-
Laurens SC-Union SC-Spartanburg SC-
503 AM EDT Fri Oct 29 2021

...A strong thunderstorm will impact portions of east central
Laurens, southeastern Spartanburg and southwestern Union Counties
through 530 AM EDT...

At 503 AM EDT, Doppler radar was tracking a strong thunderstorm 10
miles northeast of Laurens, or 5 miles north of Clinton, moving
northeast at 25 mph.

HAZARD...Half inch hail.

SOURCE...Radar indicated.

IMPACT...Minor damage to outdoor objects is possible.

Locations impacted include...
Union, Clinton, Monarch Mill, Buffalo, Rose Hill State Park, Cross
Keys, Cross Anchor, Sedalia, Santuc and Ora.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 3444 8183 3457 8199 3485 8174 3466 8150
TIME...MOT...LOC 0903Z 223DEG 21KT 3456 8185

MAX HAIL SIZE...0.50 IN
MAX WIND GUST...<30 MPH

HG

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
525 AM EDT Fri Oct 29 2021

NCZ068-508-510-SCZ007-008-291015-
Greater Rutherford NC-Cleveland NC-Eastern Polk NC-Cherokee SC-
Spartanburg SC-
525 AM EDT Fri Oct 29 2021

...Strong thunderstorms will impact portions of southeastern
Rutherford, southeastern Polk, Cleveland, northeastern Spartanburg
and Cherokee Counties through 615 AM EDT...

At 524 AM EDT, Doppler radar was tracking strong thunderstorms along
a line extending from 10 miles south of Rutherfordton to 7 miles
northeast of Spartanburg. Movement was northeast at 35 mph.

HAZARD...Winds in excess of 40 mph and half inch 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, Gaffney, Forest City, Rutherfordton, Spindale, Boiling
Springs NC, Cowpens, Blacksburg, Mayo and Chesnee.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 3558 8170 3519 8132 3517 8133 3516 8133
      3517 8137 3514 8140 3505 8141 3505 8147
      3503 8149 3496 8180 3527 8206
TIME...MOT...LOC 0924Z 245DEG 32KT 3522 8200 3502 8184

MAX HAIL SIZE...0.50 IN
MAX WIND GUST...40 MPH

HG

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
534 AM EDT Fri Oct 29 2021

SCZ008-009-013-014-291000-
York SC-Cherokee SC-Union SC-Chester SC-
534 AM EDT Fri Oct 29 2021

...A strong thunderstorm will impact portions of northwestern
Chester, southwestern York, eastern Cherokee and northern Union
Counties through 600 AM EDT...

At 534 AM EDT, Doppler radar was tracking a strong thunderstorm near
Union, moving northeast at 35 mph.

HAZARD...Winds in excess of 40 mph and half inch 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...
Union, Monarch Mill, Blacksburg, Buffalo, Jonesville, Lockhart,
Sharon, Hickory Grove, Mcconnells and Smyrna.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 3464 8161 3477 8176 3514 8153 3486 8116
TIME...MOT...LOC 0934Z 227DEG 29KT 3476 8162

MAX HAIL SIZE...0.50 IN
MAX WIND GUST...40 MPH

HG

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
554 AM EDT Fri Oct 29 2021

SCZ008-009-013-291045-
York SC-Cherokee SC-Union SC-
554 AM EDT Fri Oct 29 2021

...A strong thunderstorm will impact portions of western York,
eastern Cherokee and northeastern Union Counties through 645 AM
EDT...

At 554 AM EDT, Doppler radar was tracking a strong thunderstorm 11
miles northeast of Union, or 6 miles northwest of Lockhart, moving
northeast at 35 mph.

HAZARD...Winds in excess of 40 mph and half inch 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...
York, Clover, Sharon, Hickory Grove, Smyrna, Kings Mountain State
Park, Lockhart, Saratt, Kings Creek and Adamsburg.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 3482 8142 3482 8149 3481 8147 3479 8146
      3475 8150 3486 8167 3517 8144 3515 8106
TIME...MOT...LOC 0954Z 216DEG 29KT 3487 8154

MAX HAIL SIZE...0.50 IN
MAX WIND GUST...40 MPH

HG

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
602 AM EDT Fri Oct 29 2021

NCZ056-068>070-502-504-508-291045-
Greater Rutherford NC-Gaston NC-Cleveland NC-Lincoln NC-
Greater Burke NC-Greater Caldwell NC-Catawba NC-
602 AM EDT Fri Oct 29 2021

...Strong thunderstorms will impact portions of western Catawba,
northeastern Rutherford, Lincoln, southern Caldwell, Cleveland,
northwestern Gaston and Burke Counties through 645 AM EDT...

At 601 AM EDT, Doppler radar was tracking strong thunderstorms along
a line extending from 9 miles northeast of Rutherfordton to 12 miles
northeast of Forest City to 4 miles south of Shelby. Movement was
northeast at 35 mph.

HAZARD...Winds in excess of 40 mph and half inch 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...
Hickory, Shelby, Morganton, Newton, Lincolnton, Cherryville,
Longview, Sawmills, Granite Falls and Valdese.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 3580 8133 3552 8107 3517 8146 3517 8155
      3540 8173 3552 8193 3553 8192 3554 8185
      3556 8183 3558 8182 3565 8185 3589 8171
TIME...MOT...LOC 1001Z 214DEG 29KT 3549 8188 3544 8170 3522 8153

MAX HAIL SIZE...0.50 IN
MAX WIND GUST...40 MPH

HG