Severe Thunderstorm Warning 267, NWS Greenville-Spartanburg, SC

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
538 PM EDT Sun Sep 1 2024

.SYNOPSIS...
As a cold front drifts from north to south across our area on Monday
scattered afternoon and early evening showers and thunderstorms are
expected mainly along and south of Interstate 85.  Temperatures fall
below normal by mid week with cool high pressure ridging down from
New England.  Rain chances increase again by the end of the week.

&&

.NEAR TERM /THROUGH MONDAY/...
As of 530 PM EDT Sunday: Rather extensive coverage of convection
across the forecast area attm, but so far not very organized or
robust. Very moist air mass in place and deep warm-cloud layers
will support efficient rain rates, so concern for locally excessive
rainfall and flash flooding is increasing a bit. Fortunately,
storms have a steady forward motion. There is still some severe
threat of damaging wind gusts wherever we can get some cell mergers
and quasi-organization around outflows. Convection over eastern TN
so far has not been severe, but will closely monitor the activity
as it enters the NC mountains. The latest CONSShort seems to have
a decent handle on the timing and coverage, so blended that in to
the PoPs thru tonight. Expect a fairly slow decrease from NW to
SE of coverage this evening.

Otherwise, a broad upper trough and associated vort axis will
continue to slide across the area through this evening and into the
overnight hours. Vertical profiles are similar to the past few days,
with the exception of slightly stronger shear (15-20 kts). This
is enough to support a few multicell clusters as convection grows
in coverage and slips east into the Piedmont zones. A few storms
will be strong to severe, however, morning clouds didn't allow
environmental parameters to build to their full potential. With
PWAT values around 2.00", there will also be a localized flash
flood threat. CAMs keep some of this activity going into the
overnight hours, especially in areas that are left untapped. Kept
a mentionable PoP in places along and south and east of the I-85
corridor, where consensus for this is greatest. Mountain valley
fog/low stratus is expected again and should develop in places
that receive rainfall. Otherwise, cloud debris will hangout for
a good portion of the nighttime period with lows a category or so
above normal.

Monday's forecast will be tricky due to the difference in
model guidance on where the pre-frontal trough boundary will be
located. Winds are expected to turn more north to easterly as
this boundary sags south into the region. Orographically initiated
convection is possible along the Blue Ridge Escarpment during peak
heating, which is being proposed by the CAMs. Not confident in this
development as drier air will filter in behind the front, but kept
lingering PoPs as it's hard to ignore. The upper trough axis should
be east of the CFWA by the end of the forecast period and subtle
changes in the airmass will start to become noticeable. Afternoon
highs will be near-normal for most locations.

&&

.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/...
As of 250 PM Sunday: By Monday evening, the surface high moving
across the Great Lakes region will already be moving into position
to support a nascent cold air damming wedge that will build
down east of the mtns overnight. Some remaining easterly flow
will support a precip chance close to the Blue Ridge Escarpment
lingering into the evening, but dry air advecting in from the
northeast will dry that up in short order. From that point onward,
through Tuesday and Wednesday, the situation looks like classic
summertime dry wedge as a parent high slowly strengthens and moves
across NY/PA to the New England coast. Temps will be on the order
of ten degrees below normal with a dry air mass, quite the rarity
compared to what the first week of September is usually like. Alas,
all good things must come to an end, and moisture may start to drift
back up from the southwest late Wednesday. Small precip chances
will be reintroduced in the S flow upslope areas by overnight,
but this could be too quick.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
As of 228 PM Sunday: The model guidance continues to come more into
agreement with the slow demise of a summertime cold air damming
wedge Thursday as the weakening parent high retreats eastward off
the Canadian Maritimes. Although, at the same time, light precip
developing SW-to-NE with moisture return and the commencement of
low level isentropic lift will act to preserve a cool pool in the
usual damming region. Precip probs are kept in the chance range,
spreading northeast across the region during the day, if only
because of lingering timing issues with the onset. The trend
is expected to go toward higher probs. The remnants of a weak
disturbance aloft should take weak low pressure across the Deep
South and then eastward along the old wedge boundary on Friday,
looking somewhat like you might seen in winter. Rain looks like a
pretty good bet given the consensus in the model guidance, but the
model blend and our usual conservative nature for systems out on
Day 5 keeps our precip prob close to 50 pct. Again, expect this to
be fine tuned upward. The weak low should move away on Saturday,
but the blend retains a chance of rain because of slower timing
in some of the ensemble members. The low finally departs and then
drains away the remnant cool pool by Sunday, so precip probs go down
and hopefully we salvage part of the day. Temps will remain on the
order of 10 degrees below normal, until we begin to rebound Sunday.

&&

.AVIATION /22Z SUNDAY THROUGH FRIDAY/...
At KCLT and elsewhere: Few showers and thunderstorms have initiated
across the mountains and are expected to impact KAVL over the
next hour or two. Field of cu with close to MVFR level cigs will
continue to grow in coverage, as well as the potential for showers
and thunderstorms, which is reflected with TEMPO groups at all
terminals. Kept the mention of IFR TSRA and gusty/vrb winds due
to the more widespread coverage expected compared to the previous
few days. Winds are generally southwesterly, but should shift to
a northwesterly component later this evening, once the line of
showers and thunderstorms push to the south and east. Another round
of fog/low stratus is expected, especially in the mountain valleys
and in areas that receive rainfall. Model guidance are hitting the
NC terminals hard with IFR low stratus and decided to follow it
by placing this mention in the latest TAF update at KCLT and KHKY,
with KAVL already expected to drop as well. Lingering showers are
possible overnight, so kept some kind of VCSH mention to handle this
potential development. Winds veer more northeasterly to easterly
on Monday as a weak boundary slips south of the area. Can't rule
out a shower or thunderstorm Monday afternoon, but confidence is
too low for a TAF mention at this time.

Outlook: Sfc front should settle south thru the area Mon and could
support a few more TSRA. Then dry air moves in from the north
and should result in relatively quiet weather thru the middle of
the week.

&&

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

&&

SYNOPSIS...DEO
NEAR TERM...ARK/CAC
SHORT TERM...PM
LONG TERM...PM
AVIATION...CAC

Hazardous Weather Outlook
National Weather Service Greenville-Spartanburg SC
430 AM EDT Sun Sep 1 2024

GAZ010-017-018-026-028-029-NCZ033-035>037-048>053-056>059-062>065-
068>072-082-501>510-SCZ008>014-019-101>109-020830-
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-
430 AM EDT Sun Sep 1 2024

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

.DAY ONE...Today and tonight.

Scattered to numerous showers and thunderstorms are expected on
Sunday afternoon into early Sunday evening. A few storms may become
strong to severe with damaging wind gusts as the main threat. Also,
locally heavy rainfall may lead to isolated flooding.

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

Hazardous weather is not expected at this time.

.SPOTTER INFORMATION STATEMENT...

None.

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
525 PM EDT Sun Sep 1 2024

NCZ068-070-SCZ009-012215-
Gaston NC-Cleveland NC-York SC-
525 PM EDT Sun Sep 1 2024

...A STRONG THUNDERSTORM WILL IMPACT SOUTHEASTERN CLEVELAND...WESTERN
GASTON AND NORTHWESTERN YORK COUNTIES THROUGH 615 PM EDT...

At 525 PM EDT, Doppler radar was tracking a strong thunderstorm 10
miles west of Gastonia, or near Kings Mountain, moving northeast at
20 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...
Gastonia, Kings Mountain, Bessemer City, South Gastonia, Dallas,
Crowders Mountain State Park, Kings Mountain State Park, Crowders,
and Bethany.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 3518 8110 3510 8140 3514 8140 3516 8137
      3517 8144 3527 8144 3536 8118
TIME...MOT...LOC 2125Z 245DEG 16KT 3520 8134

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

TW

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
526 PM EDT Sun Sep 1 2024

NCZ035-036-012215-
Iredell NC-Alexander NC-
526 PM EDT Sun Sep 1 2024

...A STRONG THUNDERSTORM WILL IMPACT NORTHERN ALEXANDER AND NORTH
CENTRAL IREDELL COUNTIES THROUGH 615 PM EDT...

At 526 PM EDT, Doppler radar was tracking a strong thunderstorm 11
miles south of Ronda, or 4 miles north of Love Valley, moving east at
10 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.

Locations impacted include...
Love Valley, Vashti, and Union Grove.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 3605 8084 3599 8085 3598 8133 3601 8131
      3601 8129 3603 8127 3604 8120 3603 8118
      3603 8117 3604 8113 3603 8107 3606 8098
TIME...MOT...LOC 2126Z 278DEG 9KT 3605 8097

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

TW

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
536 PM EDT Sun Sep 1 2024

GAZ017-012215-
Habersham GA-
536 PM EDT Sun Sep 1 2024

...A STRONG THUNDERSTORM WILL IMPACT SOUTHERN HABERSHAM COUNTY
THROUGH 615 PM EDT...

At 536 PM EDT, Doppler radar was tracking a strong thunderstorm 7
miles southwest of Clarkesville, or near Baldwin, moving east at 10
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 hail damage to outdoor objects is
         possible.

Locations impacted include...
Cornelia, Baldwin, Demorest, Mount Airy, Alto, and Raoul.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 3454 8362 3457 8363 3458 8341 3448 8346
      3448 8347 3449 8354 3445 8359 3445 8360
      3443 8362 3444 8362 3450 8367
TIME...MOT...LOC 2136Z 273DEG 10KT 3452 8358

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

TW

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
538 PM EDT Sun Sep 1 2024

NCZ070-071-012215-
Gaston NC-Mecklenburg NC-
538 PM EDT Sun Sep 1 2024

...A STRONG THUNDERSTORM WILL IMPACT WEST CENTRAL MECKLENBURG AND
EASTERN GASTON COUNTIES THROUGH 615 PM EDT...

At 538 PM EDT, Doppler radar was tracking a strong thunderstorm 4
miles east of Gastonia, or near Mcadenville, moving northeast 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...
Gastonia, Mt Holly, Belmont, Stanley, Cramerton, Lowell, Ranlo,
Mcadenville, Charlotte Douglas Airport, and Paw Creek.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 3516 8109 3536 8118 3541 8105 3540 8101
      3520 8090
TIME...MOT...LOC 2138Z 245DEG 12KT 3525 8109

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

TW

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
554 PM EDT Sun Sep 1 2024

NCZ069>071-012230-
Gaston NC-Lincoln NC-Mecklenburg NC-
554 PM EDT Sun Sep 1 2024

...A STRONG THUNDERSTORM WILL IMPACT SOUTHEASTERN LINCOLN...
NORTHWESTERN MECKLENBURG AND NORTHEASTERN GASTON COUNTIES THROUGH 630
PM EDT...

At 553 PM EDT, Doppler radar was tracking a strong thunderstorm 9
miles southwest of Huntersville, or near Mt Holly, moving northeast
at 30 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...
Huntersville, Northeast Charlotte, Northwest Charlotte, Cornelius,
Davidson, Westport, University City, Paw Creek, Ramsey Creek Park,
and Hidden Valley.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 3523 8092 3534 8098 3541 8105 3541 8110
      3550 8101 3552 8096 3550 8096 3549 8094
      3551 8091 3551 8079 3542 8075 3540 8077
      3532 8068
TIME...MOT...LOC 2153Z 240DEG 26KT 3533 8097

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

TW

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
558 PM EDT Sun Sep 1 2024

GAZ026-028-012245-
Hart GA-Franklin GA-
558 PM EDT Sun Sep 1 2024

...A STRONG THUNDERSTORM WILL IMPACT EASTERN FRANKLIN AND HART
COUNTIES THROUGH 645 PM EDT...

At 558 PM EDT, Doppler radar was tracking a strong thunderstorm 7
miles west of Hartwell, or near Bowersville, moving east at 20 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...
Hartwell, Royston, Reed Creek, Lavonia, Gumlog, Canon, Franklin
Springs, Bowersville, Tugaloo State Park, and Victoria Bryant State
Park.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 3422 8300 3423 8299 3423 8308 3426 8312
      3427 8312 3424 8318 3444 8324 3450 8307
      3447 8301 3448 8299 3449 8290 3447 8287
      3437 8284 3434 8279 3429 8277 3425 8291
      3421 8298
TIME...MOT...LOC 2158Z 249DEG 19KT 3439 8306

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

TW