Severe Thunderstorm Warning 178, NWS Greenville-Spartanburg, SC

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
932 AM EDT Thu Jun 26 2025

.SYNOPSIS...
Another hot and humid day today, thanks to a large upper ridge
over the area. The ridge gradually weakens, allowing temperatures
to get closer to normal by the weekend. A disturbance meandering
over the Deep South will yield scattered to numerous showers and
thunderstorms each day, especially during the afternoon and evening
hours. A weak cold front reaches our region by Tuesday.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 928 AM Thursday...

Key Messages:

1) Hot and Humid Again but not as Hot or Humid as the Last Two Days

2) Heat Advisory in Effect from 2PM to 8PM Along the I-77 Corridor

3) Another Round of Strong to Severe Storms Develops this Afternoon
and Evening but Coverage and Intensity Should be Less than Yesterday

A couple stray showers continue to drift across the area with a
couple returns over the mountains and another small shower over
Lincoln County. Overall, the forecast remains dry through the rest
of the morning before another round of diurnally driven storms this
afternoon. No changes were needed with this update.

Weak upper ridging remains over the eastern United States while a
weak upper low lifts northward over Florida through the period. This
will allow the heat and humidity to lower just a bit today (we will
take any relief we can get at this point). Temps this afternoon will
end up ~3-4 degrees cooler compared to yesterday but will still end
up around 5-10 degrees above normal. Highs will range from the low
to mid 90s east of the mountains and the upper 80s to lower 90s
across the mountain valleys. Triple digit heat indices are once
again expected, mainly east of the NC mountains. However, the
Caldwell, Burke, McDowell, Rutherford and Polk mountain zones will
see triple digit heat indices return today. Locations along/near the
I-77 corridor are most likely to reach Heat Advisory criteria this
afternoon/early evening so the Heat Advisory remains in effect from
2pm to 8pm. Heat indices in the advisory will range from 105-108
degrees F. Another round of strong to severe storms can be expected
this afternoon and evening but activity is not expected to be a
robust as what we saw yesterday. Although deep layer shear will
increase slightly, ranging from 10-15 kts, both SBCAPE and DCAPE
will a few hundred J/kg lower than yesterday. SBCAPE should
generally range from 2,000-3,000 J/kg with DCAPE ranging from 900-
1,300 J/kg per the latest high res guidance and model soundings. The
Day 1 SPC Severe Weather Outlook has the entire forecast area in a
Marginal risk for severe storms and this appears warranted based on
the expected environment today. Damaging wind gusts from microbursts
will continue to be the main hazard with any severe storms that
develop but isolated, brief large hail is also possible. The Day 1
WPC Excessive Rainfall Outlook has most of the forecast area in a
Marginal risk so the isolated heavy rainfall/flooding threat will
return again today (especially for areas that saw heavy rainfall
yesterday and that get heavy rainfall again today).

Drier conditions will gradually develop late this evening into
tonight once convection wanes. Lows tonight will be similar to this
morning, ending up around 5-8 degrees above normal. Patchy mountain
valley fog and low stratus should develop again tonight into
daybreak Friday.

&&

.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
As of 250 AM EDT Thursday: The pattern will remain unsettled with
showers and storms expected again Friday and Saturday. Coverage
should be enhanced with an upper diffluent pattern in between a
weak upper low near FL and a flat trough over the Great Lakes. The
typical mountaintop and lee trough convergence will be the triggers
for convective initiation, and shear and thermal profiles will
support a pulse storm mode. The NBM has categorical PoPs in the
mountains tapering to likely in the Foothills and high-end chc
southeast of I-85. This seems a little high, but over a 12-hour
period, coverage may largely verify these values. A few strong
wet microbursts can be expected both days from mid aftn to early
evening. Also, weak steering flow and elevated PWATs will yield an
isolated/localized heavy rain/flood threat. Temps will continue
to be slightly above normal, with highs in the upper 80s in the
lowest mountain valleys and lower 90s east of the mountains. Lows
in the 60s in the mountains and generally 68-74 east. Dewpts do
not mix out much either day, keeping heat indices elevated and
possibly topping out in the 100-105 deg F range in the southern
Upper Savannah Valley and the Charlotte area. But not expecting
to need a Heat Advisory either day.

&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
As of 300 AM EDT Thursday: A weak upper low will open up into a
relative weakness in the subtropical ridge over FL/GA Sunday,
while a northern stream trough digs into the Great Lakes and
Ohio Valley. This set up should keep enhanced diurnal convection
going thru the first half of next week. In fact, the deterministic
guidance shows even more convective response Sunday thru Tuesday
than what we're expecting Friday and Saturday. The digging trough
will bring a weak cold front SE toward the forecast area and may
provide extra convergence for convection Tuesday. Pretty much every
day has similar PoPs and temps, with a slight uptick in PoPs and a
slight downward trend in max temps Tuesday. The above-climo PoPs may
increase excessive rain/flash flood threats as we continue with this
pattern. Sever threat should remain a few wet microbursts each day,
with perhaps an increase in more organized storms Tuesday thanks
to a little more shear and upper divergence associated with the
digging upper trough.

There is disagreement between the GFS and ECMWF on whether the cold
front will push far enough thru the forecast area to dry us out
and bring temps back to normal. The GFS hangs the front up across
the Piedmont, while the EC pushes it to the I-20 corridor. It's
difficult for a front to clear thru the area this time of year,
and the EC seems to be on the more amplified side of the LREF
guidance on the 500 mb trough. So while PoPs are lower, they are
still elevated for Wednesday (50-70%).

&&

.AVIATION /14Z THURSDAY THROUGH MONDAY/...
At KCLT and elsewhere: VFR and dry through the late morning or early
afternoon hours. Mountain valley fog and low stratus have developed
but confidence on whether this will reach KAVL remains very low.
Winds will remain calm to light and VRB through the 12Z TAF period.
Daytime VFR cumulus will develop again this afternoon and evening.
Another round of scattered to numerous thunderstorms will develop
again this afternoon into late this evening across the terminals.
Went with TEMPOs for TSRA and associated restrictions from ~20Z-24Z
(19-23Z at KHKY and KAVL) followed by PROB30s for TSRA towards the
end of the period. VFR will gradually return late this evening into
tonight once TSRA subsides. Mountain valley fog and low stratus will
develop again tonight into daybreak Friday but confidence on whether
this will reach KAVL is low.

Outlook: Daily chances for afternoon and evening showers and
thunderstorms continue into next week. Fog and/or low stratus will
be possible each morning in the usual mountain valleys as well as
near lakes and rivers.

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...None.
NC...Heat Advisory from 2 PM this afternoon to 8 PM EDT this
     evening for NCZ036-037-057-071-072-082.
SC...None.

&&

SYNOPSIS...ARK
NEAR TERM...AR/TW
SHORT TERM...ARK
LONG TERM...ARK
AVIATION...AR

Hazardous Weather Outlook
National Weather Service Greenville-Spartanburg SC
337 AM EDT Thu Jun 26 2025

GAZ010-017-018-026-028-029-NCZ033-035-048>053-056-058-059-062>065-
068>070-501>510-SCZ008>014-019-101>109-270745-
Rabun-Habersham-Stephens-Franklin-Hart-Elbert-Avery-Alexander-
Madison-Yancey-Mitchell-Swain-Haywood-Buncombe-Catawba-Graham-
Northern Jackson-Macon-Southern Jackson-Transylvania-Henderson-
Cleveland-Lincoln-Gaston-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-Chester-Greenwood-
Oconee Mountains-Pickens Mountains-Greenville Mountains-
Greater Oconee-Greater Pickens-Central Greenville-
Southern Greenville-Northern Spartanburg-Southern Spartanburg-
337 AM EDT Thu Jun 26 2025

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

.DAY ONE...Today and tonight.

Strong to severe storms will develop again this afternoon and
evening. Any severe storm that develops will have the potential to
produce damaging wind gusts. Isolated,brief large hail is also
possible.

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

Strong to severe storms will develop again Friday afternoon and
evening. Any severe storm that develops will have the potential to
produce damaging wind gusts. Isolated,brief large hail is also
possible.

.SPOTTER INFORMATION STATEMENT...

None.

NCZ036-037-057-071-072-082-270745-
Iredell-Davie-Rowan-Mecklenburg-Cabarrus-Union-
337 AM EDT Thu Jun 26 2025

...HEAT ADVISORY REMAINS IN EFFECT FROM 2 PM THIS AFTERNOON TO 8 PM
EDT THIS EVENING...

This Hazardous Weather Outlook is for Piedmont North Carolina.

.DAY ONE...Today and tonight.

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

   Heat Advisory.

Strong to severe storms will develop again this afternoon and
evening. Any severe storm that develops will have the potential to
produce damaging wind gusts. Isolated,brief large hail is also
possible.

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

Strong to severe storms will develop again Friday afternoon and
evening. Any severe storm that develops will have the potential to
produce damaging wind gusts. Isolated,brief large hail is also
possible.

.SPOTTER INFORMATION STATEMENT...

None.

AR

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Preliminary Local Storm Report
National Weather Service Greenville-Spartanburg SC
1129 AM EDT Thu Jun 26 2025

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0625 PM     Tstm Wnd Dmg     2 NW Trinity            34.86N 80.55W
06/25/2025                   Union              NC   Public

            Social media video of a tree down across a
            fence.

&&

TW

Preliminary Local Storm Report
National Weather Service Greenville-Spartanburg SC
1137 AM EDT Thu Jun 26 2025

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0928 PM     Tstm Wnd Dmg     3 W Turnerville         34.69N 83.48W
06/25/2025                   Habersham          GA   Public

            Tree down along The Orchard Road.

&&

TW

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
1139 AM EDT Thu Jun 26 2025

NCZ033-501-261615-
Caldwell Mountains NC-Avery NC-
1139 AM EDT Thu Jun 26 2025

...A STRONG THUNDERSTORM WILL IMPACT NORTHWESTERN CALDWELL AND
SOUTHEASTERN AVERY COUNTIES THROUGH 1215 PM EDT...

At 1139 AM EDT, Doppler radar was tracking a strong thunderstorm near
Blowing Rock, or near Blowing Rock In Caldwell County, moving
southwest at 10 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...
Blowing Rock In Caldwell County, B.R. Parkway-Linville Falls To
Grandfather, Grandfather Mountain State Park, Edgemont, Globe, Upton,
Linville, Patterson, Collettsville, and Pineola.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

&&

LAT...LON 3612 8156 3607 8150 3598 8157 3594 8166
      3590 8171 3605 8190 3611 8179 3612 8169
TIME...MOT...LOC 1539Z 042DEG 8KT 3608 8164

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

RWH

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
1203 PM EDT Thu Jun 26 2025

GAZ010-NCZ059-062>064-SCZ101-261630-
Rabun GA-Transylvania NC-Southern Jackson NC-Northern Jackson NC-
Macon NC-Oconee Mountains SC-
1203 PM EDT Thu Jun 26 2025

...A STRONG THUNDERSTORM WILL IMPACT NORTHEASTERN RABUN...
SOUTHEASTERN MACON...SOUTHWESTERN TRANSYLVANIA...SOUTHEASTERN JACKSON
AND NORTH CENTRAL OCONEE COUNTIES THROUGH 1230 PM EDT...

At 1202 PM EDT, Doppler radar was tracking a strong thunderstorm 20
miles east of Franklin, or near Cashiers, moving southwest at 10 mph.

HAZARD...Wind gusts up to 40 mph and half inch 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...
Highlands, Cashiers, Gorges State Park, Lake Glenville, Lake
Jocassee, Ellijay, Tuckasegee, Sapphire, Bad Creek, and Whiteside
Mountain.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

&&

LAT...LON 3533 8311 3506 8290 3485 8305 3510 8341
TIME...MOT...LOC 1602Z 042DEG 8KT 3507 8304

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

RWH