Multiple supercell thunderstorms developed in the vicinity of a warm front across the South Carolina Piedmont throughout the afternoon. Despite exhibiting intense rotation at times, severe weather from these storms was limited to one brief, weak tornado, isolated large hail, and straight line wind gusts as high as 85 mph.
Every event with a place to put it. Tap one for its entry below.
Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS GSP wrote it up.
Multiple supercell thunderstorms developed in the vicinity of a warm front across the South Carolina Piedmont throughout the afternoon. Despite exhibiting intense rotation at times, severe weather from these storms was limited to one brief, weak tornado, isolated large hail, and straight line wind gusts as high as 85 mph.
The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Greenville-Spartanburg, SC wrote its last area forecast discussion before the first event at Mar 25, 1:57 PM EST, 1 hour 27 minutes earlier.
Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
257 PM EDT Thu Mar 25 2021
.SYNOPSIS...
A vigorous cold front is expected to move through the area later
tonight and into Friday and could produce isolated strong to severe
convection along with significant rainfall. The active pattern
continues this weekend as another cold front slides through the
area on Sunday bringing another round of showers and thunderstorms.
&&
.NEAR TERM /THROUGH FRIDAY/...
As of 230 PM Thursday: The warm front has centered itself to over
the CFWA, with a slight dip over the Upstate, which is indicated by
the N to NE-ly via Metar Obs. Pre-frontal activity is ongoing over
the mountains and NE GA, with elevated instability building in
around the proximity of the warm front. This should continue through
the rest of the day and into tonight before the cold front enters in
from the west. Some of these storms will be strong to severe as
daytime heating continues and dewpoints trending into the 60s in
most locations outside the mountains, which is allowing the
atmosphere to destabilize slightly more than initially thought.
Another trend to watch is the convective debris from the west that
could alter sfc insolation and maintain mostly cloudy skies ahead of
any pre-frontal or frontal related precip, which would ultimately
limit SBCAPE development.
We remain under a weak WAA regime and influence of a subtropical
ridge off the SE Coast. This ridge is downstream of an expansive
trough, within which a potent shortwave will move today, driving
development of a low pressure system over the lower MS Valley. A
significant severe outbreak is expected over portions of the TN, MS,
and AL. Fairly brisk southerly flow has already initiated convection
over the high terrain. The depth and strength of moisture advection
will be impressive, leading to PWATs peaking near +3 SD, and IVT
parameter values that are also anomalously large. Deep layer
hodographs will already be long and curving, but midlevel lapse
rates are not the greatest; the limited instability will keep our
severe threat comparatively small during the day, with convective
layers too shallow to realize all the shear. This does somewhat
limit our heavy rain threat as well, though there will be widespread
coverage and potential for multiple rounds thru tonight. WPC Day 1
ERO includes most of our SW mtns in a Moderate Risk, partly because
of the aforementioned anomalies and high probabilities for
significant rain rates from the HREF. We are hoisting a Flash Flood
Watch from 18z today to 12z Fri. The same southerly flow will lead
to rather gusty winds, and higher elevations of the mtns will be
exposed to near Wind Advisory-level conditions.
LLJ is expected to precede the cold front into our area in the
early evening, again enhancing precip generation along the srn
end of the Appalachians; a narrow tongue of sfc based instability
will linger until the front itself enters in the late evening. A
convective line, likely with some embedded rotation will support
vague supercell structure. The dynamic lift provided by the
shortwave will mostly miss our area to the NW as the wave tracks
north of the OH River; this coupled with the unfavorable timing,
and diminishing instability, should begin to impact the convection
particularly as it crosses the mountains. Nevertheless, a narrow
line of strong showers with a few embedded tstms could progress
across the area overnight. Prog soundings reveal that the line will
encounter poor low to midlevel lapse rates, and this would limit sfc
based updrafts and thus tornado risk. The SPC slight risk extending
only into the mtns looks well-placed and even extended slightly
further east. Recent short-term consensus PoPs as well as hourly
NBM seem to be keying better on the shadowing effect of the mtns,
and timing/chances have been revised thru tonight in new fcst grids.
The frontal boundary should push out of the region by 18z Friday
as sfc high builds in to the NW and we enter a post-frontal
environment by the very end of the forecast period. Drier weather
will prevail, with highs in the low 80s in most locations outside
the mountains and 70s in the higher elevations. One factor that
can play a role is how fast the cold front exits the region and
allows for the clouds to scour out.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
As of 145 PM EDT Thursday: the short term picks up at 00Z Saturday,
with a shortwave trough rounding the broader ridge sitting over the
east coast. By this time, forcing from the trough will largely
be tapering off to the north of our CWA, and a brief bout of
dry weather is in store for Friday night. Renewed southwesterly
flow over the Tennessee Valley will pump Gulf moisture into the
lower troposphere through the day Saturday, working with weak
mid-level forcing to produce scattered afternoon showers across TN,
spreading into the Blue Ridge Mountains and western SC Upstate
by late Saturday afternoon. The developing surface low skirts
its way northeast along the Appalachians and drags a cold front
across our area early Sunday afternoon.
Ample WAA ahead of this front paired with decent solar insolation
should prime the environment for convection, with the Piedmont
and Upstate seeing SBCAPE values in the 500-1000 J/kg range and a
40-50kt LLJ riding out ahead of the frontal boundary. Given the
timing of the frontal passage in the early afternoon, this is a
pattern to keep an eye on over the next day or two. Some precip
may still be falling for at least the eastern part of our CWA by
the end of the short term at 00Z Monday, as the front tapers off
to the east.
Temps are on track to stay several degrees above normal on Saturday
and Sunday, before dropping back to near-normal Sunday night in
the wake of the cold front.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
As of 200 PM EDT Thursday: by Sunday night, good mid-level forcing
associated with the latest trough is exiting the region to the east,
and precip drops off overnight behind the departing cold front.
We then enter a weak upper ridging regime as high pressure builds
in at the surface. So, Monday should be dominated by clear,
dry weather as the frontal boundary stalls well south of us.
Meanwhile, the GFS and ECMWF depict a closed upper low meandering
out of the Southern Plains and causing coastal cyclogenesis along
the stagnant frontal boundary. The resulting surface low tracks
from the Gulf Coast out to the NC/SC coastline. It looks to only
graze our CWA at this point, yielding chance PoPs on Tuesday
afternoon and overnight. On Thursday, yet another surface low
pushes into the region from the west, bringing another bout of
rainfall to the region to cap out the week.
Temperatures on Monday and Tuesday look to be a couple degrees
below normal, before southerly WAA brings them back to near-normal
later in the week.
&&
.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
At KCLT and elsewhere: Areas of LIFR to VLIFR cigs/vsby persist,
over all TAF sites, with the exception of KCLT and KAND. The cirrus
and convective debris from the west has kept this from expanding
much, but also delay its scattering. Model trends have become wetter
and showing slightly more instability than previous trends. Pre-
frontal activity has kicked-off over the mountains and foothills,
with some thunderstorms approaching the Upstate and thus, a tempo
for thunder has been entered in at all sites except KHKY. The HRRR
model shows this activity pushing into KCLT in the evening along
with available instability. The warm front is having a hard time
passing through the I-85 Corridor as wind directions are still
coming in from the N and NE. KCLT has veered to the SE, but is the
only terminal to do so.
A weakening convective line is expected to traverse the region
tonight; confidence not great but think MVFR cigs and locally MVFR
vsby will result as this passes the sites. The gusty winds brought
down by the line may be of more impact. Damaging wind risk is
nonzero with the storms or any stronger showers, particularly over
the western sites. Expect restrictions to lift after the fropa
tomorrow as drier air and clearing skies filter in behind the front.
Outlook: Active weather will continue until a cold front pushes
through the region Friday morning. Another system may bring rain and
associated restrictions late Saturday into Sunday.
Confidence Table...
19-01Z 01-07Z 07-13Z 13-18Z
KCLT High 100% High 96% High 90% High 92%
KGSP High 91% High 84% Med 78% High 95%
KAVL High 89% High 86% Med 61% High 100%
KHKY High 87% Med 66% Low 55% High 95%
KGMU High 90% High 83% Low 55% High 100%
KAND High 100% High 94% High 94% High 98%
The percentage reflects the number of guidance members agreeing
with the scheduled TAF issuance flight rule category. Complete hourly
experimental aviation forecast consistency tables are available at
the following link:
www.weather.gov/gsp/aviation
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...Flash Flood Watch through Friday morning for GAZ010.
NC...Flash Flood Watch through Friday morning for NCZ051-052-058-
059-062>064.
SC...None.
&&
SYNOPSIS...MPR
NEAR TERM...CAC/Wimberley
SHORT TERM...MPR
LONG TERM...MPR
AVIATION...CACHazardous Weather Outlook National Weather Service Greenville-Spartanburg SC 445 AM EDT Thu Mar 25 2021 GAZ010-NCZ059-062>064-260845- Rabun-Northern Jackson-Macon-Southern Jackson-Transylvania- 445 AM EDT Thu Mar 25 2021 ...FLASH FLOOD WATCH IN EFFECT FROM 2 PM EDT THIS AFTERNOON THROUGH FRIDAY MORNING... This Hazardous Weather Outlook is for northeast Georgia and western 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. Flash Flood Watch. Additionally, scattered thunderstorms will occur at times through tonight. Any thunderstorm will be capable of cloud-to-ground lightning. Late this afternoon and this evening, thunderstorms may move in from Tennessee which will pose a risk of damaging winds and hail up to 1 inch in diameter, and a small risk of a tornado. .DAYS TWO THROUGH SEVEN...Friday through Wednesday. Please listen to NOAA Weather Radio or go to weather.gov on the Internet for more information about the following hazards. Flash Flood Watch. .SPOTTER INFORMATION STATEMENT... Spotter activation may be needed. Please relay any information about observed severe weather to the NWS while following all local, state, and CDC guidelines. NCZ051-052-058-260845- Swain-Haywood-Graham- 445 AM EDT Thu Mar 25 2021 ...FLASH FLOOD WATCH IN EFFECT FROM 2 PM EDT THIS AFTERNOON THROUGH FRIDAY MORNING... This Hazardous Weather Outlook is for western 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. Flash Flood Watch. Additionally, scattered thunderstorms will occur at times through tonight. Any thunderstorm will be capable of cloud-to-ground lightning. Late this afternoon and this evening, thunderstorms may move in from Tennessee which will pose a risk of damaging winds and hail up to 1 inch in diameter, and a small risk of a tornado. .DAYS TWO THROUGH SEVEN...Friday through Wednesday. Please listen to NOAA Weather Radio or go to weather.gov on the Internet for more information about the following hazards. Flash Flood Watch. Saturday night and early Sunday, another round of thunderstorms is expected. These storms also may produce severe weather in the form of damaging wind and large hail. .SPOTTER INFORMATION STATEMENT... Spotter activation may be needed. Please relay any information about observed severe weather or flooding to the NWS while following all local, state, and CDC guidelines. GAZ017-018-026-028-029-NCZ053-065-501>510-SCZ001>006-010-260845- Habersham-Stephens-Franklin-Hart-Elbert-Buncombe-Henderson- 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-Anderson- 445 AM EDT Thu Mar 25 2021 This Hazardous Weather Outlook is for northeast Georgia, western North Carolina and upstate South Carolina. .DAY ONE...Today and tonight. Scattered thunderstorms will occur at times through tonight. Any thunderstorm will be capable of cloud-to-ground lightning. Tonight, a line of thunderstorms will move in from the west, posing a risk of damaging winds and hail up to 1 inch in diameter, and a tornado cannot be entirely ruled out. .DAYS TWO THROUGH SEVEN...Friday through Wednesday. No hazardous weather is expected at this time. .SPOTTER INFORMATION STATEMENT... Spotter activation may be needed. Please relay any information about observed severe weather to the NWS while following all local, state, and CDC guidelines. NCZ033-048>050-260845- Avery-Madison-Yancey-Mitchell- 445 AM EDT Thu Mar 25 2021 This Hazardous Weather Outlook is for western North Carolina. .DAY ONE...Today and tonight. Scattered thunderstorms will occur at times through tonight. Any thunderstorm will be capable of cloud-to-ground lightning. Late this afternoon and this evening, thunderstorms may move in from Tennessee which will pose a risk of damaging winds and hail up to 1 inch in diameter, and a small risk of a tornado. .DAYS TWO THROUGH SEVEN...Friday through Wednesday. Saturday night and early Sunday, another round of thunderstorms is expected. These storms also may produce severe weather in the form of damaging wind and large hail. .SPOTTER INFORMATION STATEMENT... Spotter activation may be needed. Please relay any information about observed severe weather to the NWS while following all local, state, and CDC guidelines. NCZ082-SCZ014-019-260845- Union NC-Chester-Greenwood- 445 AM EDT Thu Mar 25 2021 This Hazardous Weather Outlook is for lower piedmont North Carolina and upstate South Carolina. .DAY ONE...Today and tonight. Scattered thunderstorms will occur at times through tonight. Any thunderstorm will be capable of locally heavy rain and cloud-to- ground lightning. .DAYS TWO THROUGH SEVEN...Friday through Wednesday. The severe weather risk will continue until the line of storms moves out Friday morning. Damaging winds would be the main concern Friday morning. .SPOTTER INFORMATION STATEMENT... None. NCZ035>037-056-057-068>072-SCZ007>009-011>013-260845- Alexander-Iredell-Davie-Catawba-Rowan-Cleveland-Lincoln-Gaston- Mecklenburg-Cabarrus-Spartanburg-Cherokee-York-Abbeville-Laurens- Union SC- 445 AM EDT Thu Mar 25 2021 This Hazardous Weather Outlook is for piedmont North Carolina and upstate South Carolina. .DAY ONE...Today and tonight. Scattered thunderstorms will occur at times through tonight. Any thunderstorm will be capable of locally heavy rain and cloud-to- ground lightning. .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
114 PM EDT Thu Mar 25 2021
GAZ010-017-NCZ062-251745-
Rabun GA-Habersham GA-Macon NC-
114 PM EDT Thu Mar 25 2021
...A CLUSTER OF THUNDERSTORMS WITH INTENSE LIGHTNING WILL IMPACT
NORTHERN HABERSHAM...RABUN AND MACON COUNTIES UNTIL 145 PM EDT...
At 113 PM EDT, Doppler radar indicated the leading edge of a cluster
of thunderstorms with intense lightning along a line extending from 7
miles southeast of Andrews to 5 miles south of Hiawassee to 8 miles
northwest of Cleveland, and moving east at 45 mph.
Locations to be impacted include...
Franklin, Clayton, Mountain City, Tiger, Dillard, Sky Valley,
Tallulah Falls, Lake Burton, Nantahala Lake and Black Rock Mountain
State Park.
In addition to intense lightning, wind gusts up to 45 mph and pea
size hail will be possible in these areas.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Gusty winds can blow down trees that are dead, or that have weakened
root systems. Outdoor furniture and similar items can be tossed
around if not anchored. Seek shelter indoors.
Frequent lightning is occurring with these storms. If outdoors, try
to get indoors or into a hard topped vehicle. Otherwise, stay away
from open areas and isolated high objects such as trees. When
indoors, stay away from windows and doors and avoid using wired
electronic devices. Do not take a shower or bath. Try to unplug
unnecessary appliances before the storms approach.
&&
LAT...LON 3520 8373 3530 8351 3533 8334 3524 8329
3524 8323 3521 8322 3472 8337 3466 8366
3473 8362 3480 8368 3482 8365 3488 8366
3492 8360 3494 8360 3495 8355 3499 8355
3500 8348 3500 8352 3515 8365 3515 8374
TIME...MOT...LOC 1713Z 247DEG 37KT 3515 8371 3488 8379 3469 8385
RWHSpecial Weather Statement
National Weather Service Greenville-Spartanburg SC
144 PM EDT Thu Mar 25 2021
GAZ010-017-NCZ062-063-SCZ001-251815-
Rabun GA-Habersham GA-Southern Jackson NC-Macon NC-
Oconee Mountains SC-
144 PM EDT Thu Mar 25 2021
...A CLUSTER OF THUNDERSTORMS WITH INTENSE LIGHTNING WILL IMPACT
NORTHERN HABERSHAM...RABUN...SOUTHEASTERN MACON...SOUTHEASTERN
JACKSON AND NORTHWESTERN OCONEE COUNTIES UNTIL 215 PM EDT...
At 143 PM EDT, Doppler radar indicated the leading edge of a cluster
of thunderstorms with intense lightning along a line extending from 7
miles southeast of Franklin to 3 miles west of Clayton to 9 miles
northeast of Cleveland, and moving east at 30 mph.
Locations to be impacted include...
Clayton, Highlands, Mountain City, Tiger, Dillard, Sky Valley,
Cashiers, Tallulah Falls, Lake Burton and Tallulah Gorge State Park.
In addition to intense lightning, wind gusts up to 45 mph and pea
size hail will be possible in these areas.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Gusty winds can blow down trees that are dead, or that have weakened
root systems. Outdoor furniture and similar items can be tossed
around if not anchored. Seek shelter indoors.
Frequent lightning is occurring with these storms. If outdoors, try
to get indoors or into a hard topped vehicle. Otherwise, stay away
from open areas and isolated high objects such as trees. When
indoors, stay away from windows and doors and avoid using wired
electronic devices. Do not take a shower or bath. Try to unplug
unnecessary appliances before the storms approach.
&&
LAT...LON 3473 8362 3476 8363 3478 8366 3499 8350
3500 8348 3500 8350 3510 8343 3524 8293
3519 8299 3516 8300 3513 8298 3505 8306
3503 8301 3504 8294 3494 8301 3466 8329
3469 8334 3466 8337 3464 8365 3465 8366
TIME...MOT...LOC 1743Z 259DEG 28KT 3509 8333 3488 8347 3470 8366
RWHSpecial Weather Statement
National Weather Service Greenville-Spartanburg SC
214 PM EDT Thu Mar 25 2021
GAZ010-NCZ063-064-SCZ001-002-251845-
Rabun GA-Transylvania NC-Southern Jackson NC-Pickens Mountains SC-
Oconee Mountains SC-
214 PM EDT Thu Mar 25 2021
...STRONG THUNDERSTORMS WITH INTENSE LIGHTNING WILL IMPACT EASTERN
RABUN...TRANSYLVANIA...SOUTHEASTERN JACKSON...NORTHWESTERN PICKENS
AND NORTHERN OCONEE COUNTIES UNTIL 245 PM EDT...
At 214 PM EDT, Doppler radar indicated strong thunderstorms with
intense lightning along a line extending from 17 miles southeast of
Sylva to 11 miles north of Walhalla to 9 miles southeast of Clayton,
and moving east at 40 mph.
Locations to be impacted include...
Brevard, Walhalla, Rosman, Cashiers, Salem, Lake Toxaway, Jocassee
Gorges, Looking Glass, Devils Fork State Park and Table Rock State
Park.
In addition to intense lightning, wind gusts up to 45 mph and pea
size hail will be possible in these areas.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Gusty winds can blow down trees that are dead, or that have weakened
root systems. Outdoor furniture and similar items can be tossed
around if not anchored. Seek shelter indoors.
Frequent lightning is occurring with these storms. If outdoors, try
to get indoors or into a hard topped vehicle. Otherwise, stay away
from open areas and isolated high objects such as trees. When
indoors, stay away from windows and doors and avoid using wired
electronic devices. Do not take a shower or bath. Try to unplug
unnecessary appliances before the storms approach.
&&
LAT...LON 3491 8319 3500 8316 3500 8311 3505 8314
3521 8309 3534 8266 3529 8261 3515 8258
3512 8266 3513 8268 3510 8270 3509 8273
3507 8277 3505 8275 3507 8262 3502 8263
3486 8279 3475 8298 3472 8336 3473 8337
TIME...MOT...LOC 1814Z 257DEG 33KT 3516 8305 3493 8312 3479 8327
RWHThe Greer radar (KGSP), 44 km away, was scanning. The volume nearest the first event began at 20:20 UTC.
3 thunderstorm wind, 2 hail, 1 tornado. Local standard time, as filed.
Spotter reported multiple trees blown down along Wilsontown Rd.
Public reported quarter size hail in the Wattsville community.
NWS storm survey found the path of a weak tornado along Highway 72 in extreme eastern Laurens County. Damage was limited to multiple trees uprooted or snapped in this very rural area.
NWS storm survey found multiple trees snapped or uprooted roughly along and just north of Highway 72 from the Newberry County line to near Carlisle.
Public reported quarter size hail.
Emergency manager reported a section of roof torn off a mobile home on Old Mill Rd.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in South Carolina in 2021Every state in 2021This day in weather historyThe tornado archive for South Carolina, 2021Warnings in South Carolina, March 2021
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 951681, 951686, 951902, 951683, 951685, 951684.