Severe Thunderstorm Warning 20, NWS Greenville-Spartanburg, SC

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
258 PM EDT Thu Apr 10 2025

.SYNOPSIS...
Rain and thunderstorm chances continue through Friday. Dry and cool
weather returns for Saturday. Dry weather continues into early next
week with a warming trend.

&&

.NEAR TERM /THROUGH FRIDAY/...
As of 230 PM EDT Thursday...Initial line of convection pushing
across the mountains attm, generally light to moderate showers,
but some embedded thunderstorms trying to work into northeast
GA. This activity will steadily cross the forecast area this
aftn and will have little instability to work with. Meanwhile,
two distinct areas of convective activity can be seen upstream
across the Midwest and central TN. These are associated with
spokes of vorticity rounding through the base of large upper
trough. The CAMs all have a general idea of these two rounds
working into the forecast area this evening and overnight. The
first round should be the strongest, as peak heating 1000-1500
J/kg of sbCAPE over the Cumberland Plateau and will be combined
with around 50 kt of 0-6 km bulk shear. A marginal risk of severe
storms still looks good for the NC mountains, with a few rotating
storms or bowing line segments working in from the west early this
evening. This activity should weaken as it crosses the mountains
and loses instability, but some storms may be able to fully cross
the forecast area. Confidence on strong to severe storms east of
the mountains remains low, but a few isolated damaging wind gusts
cannot be ruled out. Then finally, the second round coming from
the Midwest may reach the forecast area late tonight, but should
lose intensity and be just another round of showers that mainly
affects the TN border counties before daybreak Friday. Lows will
be about a category above normal under mostly cloudy skies.

Friday, unsettled weather will continue as strong shortwave energy
carves out an upper low over the Ohio Valley to the Southern
Appalachians. Steep mid-level lapse rates and deep-layer QG forcing
will support convection firing across the area thru the day, peaking
in the aftn. Sfc low pres will form just east of the area, and bring
low-level around out of the W to NW. So the better instability will
shift east and severe threat should be low. Cooling temps aloft may
support some small hail in the deeper convection. Also, the highest
ridgetops could see minor snow accums. Highs will be mainly in the
50s in the mountains and 60s Piedmont, about 5-10 deg below normal.

&&

.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
As of 150 PM EDT Thursday: Closed upper low draped over the
Eastern Seaboard will be centered just north of the area, over the
Mid-Atlantic Friday night. Lingering wrap around moisture may keep
some precip in the area, even some light snow across the higher
elevations (>4000'). Dry air entrainment from northwesterly flow
will essentially shutoff any precip chances by daybreak Saturday
as the closed low lifts further north and the associated trough
axis will be in the midst of shifting from west to east across
the CFWA. Weak surface high begins to filter in from the west on
Saturday, leading to drier conditions, but cooler temperatures
as colder thicknesses remain in place and afternoon highs end
up ~10 degrees below normal. Surface high sets up shop over the
southeastern CONUS Saturday night and allows for good radiational
cooling conditions to be on display. In this case, overnight lows
will run 5-10 degrees below normal and there is potential for
frost/freeze to form over the forecast area, specifically across the
NC foothills and northern Upstate of SC, where the growing season
has started. Heights rebound by Sunday as the trough axis is fully
offshore and broad upper ridging begins to spill in from the west.
Expected a rebound in afternoon highs Sunday compared to Saturday,
with values right around normal.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
As of 250 PM Thursday: Surface high slides offshore the Southeast
Coast by Sunday afternoon/evening and will lead to a weak return
flow out of the southwest. At the same time, the upper ridge
will translate from west to east across the eastern CONUS as the
axis slips offshore later Monday. A potent shortwave trough with
a trailing cold front is shown encroaching the region from the
northwest by the early morning hours Tuesday. QPF response is
fairly weak as the better forcing remains north of the area, but
model guidance continue to show precip developing in the mountains,
mainly along the NC/TN border. Otherwise, the fropa will occur
Tuesday and another area of high pressure will move into the area
and control the sensible weather through the end of the forecast
period. There are hints of another shortwave quickly shifting across
the area by D7/D8, which could bring the next precip chances for
the CFWA. Temperatures will quickly rebound to 5-10 degrees above
normal Monday, ahead of the cold front, while temperatures return
to near-normal values through the rest of the week behind the front.

&&

.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
At KCLT and elsewhere: MVFR cigs are slow to erode from the south
to north across the foothills and Piedmont, and should continue to
scatter out this aftn. Meanwhile, a line of showers and weak tstms
moving into the NC mountains. This line is expected to weaken as it
pushes east this aftn, and will handle with TEMPOs for SHRA. Behind
this initial line of showers winds should become light SW or vrb
this evening with VFR conditions. Then another round of convection
is expected to develop in eastern TN and cross the area this
evening into the overnight. Guidance continues to support this
activity being a little stronger than this aftn's convection, so
will go with tempo and/or PROB30 for TSRA for that. Confidence in
timing is still moderate at best, as the storms may organize into a
line and pick up forward motion. Late tonight, MVFR to IFR cigs are
expected to form and with light winds, some MVFR vsby
restrictions possible thru daybreak Friday. The low clouds
should being to lift late Friday morning, with VFR conditions
expected by the end of the 18z TAF period, except for KAVL.
Winds will increase out of the W/SW in the Upstate, NW at KCLT
and KHKY, and NNW at KAVL.

Outlook: A low pressure system will bring showers (and
possibly thunderstorms) and associated restrictions into Friday
afternoon. Dry high pressure returns for the weekend into Monday.

&&

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

&&

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

Hazardous Weather Outlook
National Weather Service Greenville-Spartanburg SC
507 PM EDT Thu Apr 10 2025

NCZ033-035>037-048>050-052-053-056-057-064-065-068>072-082-501>510-
SCZ008>014-019-102-103-105>109-112115-
Avery-Alexander-Iredell-Davie-Madison-Yancey-Mitchell-Haywood-
Buncombe-Catawba-Rowan-Transylvania-Henderson-Cleveland-Lincoln-
Gaston-Mecklenburg-Cabarrus-Union-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-
Chester-Greenwood-Pickens Mountains-Greenville Mountains-
Greater Pickens-Central Greenville-Southern Greenville-
Northern Spartanburg-Southern Spartanburg-
507 PM EDT Thu Apr 10 2025

This Hazardous Weather Outlook is for Piedmont North Carolina,
western North Carolina and Upstate South Carolina.

.DAY ONE...Tonight.

Scattered thunderstorms will cross the area this evening. A few of
the thunderstorms strong to severe, with damaging wind gusts as the
main threat.

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

No hazardous weather is expected at this time.

.SPOTTER INFORMATION STATEMENT...

None.

GAZ010-017-018-026-028-029-NCZ051-058-059-062-063-SCZ101-104-112115-
Rabun-Habersham-Stephens-Franklin-Hart-Elbert-Swain-Graham-
Northern Jackson-Macon-Southern Jackson-Oconee Mountains-
Greater Oconee-
507 PM EDT Thu Apr 10 2025

...SEVERE THUNDERSTORM WATCH 137 IN EFFECT UNTIL MIDNIGHT EDT
TONIGHT...

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

 Severe Thunderstorm Watch.

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

No hazardous weather is expected at this time.

.SPOTTER INFORMATION STATEMENT...

None.

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
614 PM EDT Thu Apr 10 2025

NCZ058-102300-
Graham NC-
614 PM EDT Thu Apr 10 2025

...A STRONG THUNDERSTORM WILL IMPACT NORTHERN GRAHAM COUNTY THROUGH
700 PM EDT...

At 613 PM EDT, Doppler radar was tracking a strong thunderstorm 8
miles northwest of Robbinsville, or 4 miles west of Town Of
Santeetlah, moving east at 25 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...
Fontana Lake, Stecoah, Robbinsville, Fontana Village, Tapoco,
and Lake Santeetlah.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

A Severe Thunderstorm Watch remains in effect until midnight EDT for
western North Carolina.

&&

LAT...LON 3537 8401 3541 8402 3546 8396 3545 8394
      3547 8390 3545 8386 3545 8382 3544 8381
      3545 8380 3544 8376 3545 8373 3543 8366
      3531 8369 3533 8403
TIME...MOT...LOC 2213Z 267DEG 24KT 3538 8394

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

MPR

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
621 PM EDT Thu Apr 10 2025

NCZ048-102300-
Madison NC-
621 PM EDT Thu Apr 10 2025

...A STRONG THUNDERSTORM WILL IMPACT CENTRAL MADISON COUNTY THROUGH
700 PM EDT...

At 621 PM EDT, Doppler radar was tracking a strong thunderstorm 11
miles north of Marshall, or 6 miles northeast of Hot Springs, moving
east at 30 mph.

HAZARD...Pea size hail.

SOURCE...Radar indicated.

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

Locations impacted include...
Faust, Allenstand, Mars Hill, and Wolf Ridge.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 3600 8261 3599 8260 3597 8261 3595 8257
      3598 8251 3595 8248 3593 8250 3591 8249
      3591 8247 3580 8253 3592 8287 3595 8286
      3592 8282 3593 8281 3597 8278 3598 8279
      3600 8278 3602 8272
TIME...MOT...LOC 2221Z 290DEG 25KT 3596 8276

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

MPR

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
645 PM EDT Thu Apr 10 2025

NCZ051-052-058-102330-
Haywood NC-Graham NC-Swain NC-
645 PM EDT Thu Apr 10 2025

...STRONG THUNDERSTORMS WILL IMPACT SWAIN...NORTHEASTERN GRAHAM AND
NORTHWESTERN HAYWOOD COUNTIES THROUGH 730 PM EDT...

At 644 PM EDT, Doppler radar was tracking strong thunderstorms along
a line extending from 13 miles southeast of Newport to 12 miles north
of Robbinsville. Movement was east at 45 mph.

HAZARD...Wind gusts up to 50 mph and nickel 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...
Waterville, Smoky Mountains, Cherokee, Fines Creek, Deals Gap,
Balsam Mountain, and Fontana Lake.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

A Severe Thunderstorm Watch remains in effect until midnight EDT for
western North Carolina.

&&

LAT...LON 3552 8388 3556 8377 3558 8360 3556 8358
      3556 8350 3566 8335 3566 8330 3573 8324
      3572 8320 3576 8316 3579 8308 3574 8292
      3564 8288 3551 8318 3552 8324 3547 8332
      3547 8334 3544 8336 3535 8356 3547 8394
TIME...MOT...LOC 2244Z 291DEG 41KT 3579 8310 3550 8387

MAX HAIL SIZE...0.88 IN
MAX WIND GUST...50 MPH

MPR