Alert archive / South Carolina / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 18, NWS Greenville-Spartanburg, SC

March 27, 2021Greenville County, Pickens County, South Carolina

NWS Greenville-Spartanburg, SC issued this severe thunderstorm warning at Mar 27, 2021, 7:05 PM EDT for Greenville County, Pickens County, South Carolina. It was in force for 25 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Mar 27, 2021, 7:05 PM EDT (23:05 UTC)
Expired
Mar 27, 2021, 7:30 PM EDT
In force
25 min
Issued by
NWS Greenville-Spartanburg, SC
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

Counties Greenville County, SC, Pickens County, SC

The radar

The Greer radar (KGSP), 48 km from the middle of the area, began a volume at 23:07 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

Did it verify

Not verified. The Iowa Environmental Mesonet's Cow found no qualifying storm report inside this severe thunderstorm warning while it was in force. That is not proof nothing happened: reports are thin where few people live.

Cow counts a report within 15 km of the polygon while the warning was in force: a tornado for a tornado warning; hail of 1 inch or more, a gust of 58 mph or more or wind damage for a severe thunderstorm warning; a flash flood report for a flash flood warning.

The nearest sounding before it

Peachtre/Fal Fld, GA (KFFC), launched 12:00Z, 11.1 hours before the alert went out and 239 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Peachtre/Fal Fld, GA at 12:00Z on 2021-03-27Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1023 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Peachtre/Fal Fld, GA at 12:00Z on 2021-03-27The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 108 square meters per square second.1939587897Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
1023 J/kg
Mixed-layer CIN
-11 J/kg
Mixed-layer LCL
484 m above ground
0-6 km bulk shear
44 kt
0-1 km storm-relative helicity
108 m²/s²
0-3 km storm-relative helicity
130 m²/s²
Significant tornado parameter
0.0
Supercell composite
2.1

Open this sounding in Storm Lab

The text

As transmitted.

366 
WUUS52 KGSP 272305
SVRGSP
SCC045-077-272330-
/O.NEW.KGSP.SV.W.0018.210327T2305Z-210327T2330Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Greenville-Spartanburg SC
705 PM EDT Sat Mar 27 2021

The National Weather Service in Greenville-Spartanburg has issued a

* Severe Thunderstorm Warning for...
  Northwestern Greenville County in Upstate South Carolina...
  Northern Pickens County in Upstate South Carolina...

* Until 730 PM EDT.

* At 705 PM EDT, a severe thunderstorm was located 6 miles northwest
  of Pickens, or 5 miles east of Jocassee Gorges, moving east at 20
  mph.

  HAZARD...60 mph wind gusts and quarter size hail.

  SOURCE...Radar indicated.

  IMPACT...Minor hail damage to vehicles is expected. Expect wind 
           damage to trees and power lines.

* Locations impacted include...
  Pickens, Keowee Toxaway State Park, Table Rock State Park, Jocassee
  Gorges, Sunset, Pumpkintown, Dacusville, Nine Times, Cleveland and
  Slater-Marietta.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Scattered trees and power lines will be blown down in the warned
area. Seek shelter inside an interior room.

Please report damaging winds, hail, or flooding to the National
Weather Service Greenville-Spartanburg by calling toll free, 1, 800,
2 6 7, 8 1 0 1, or by posting on our Facebook page, or Tweet it using
hashtag nwsgsp. Your message should describe the event and the
specific location where it occurred.

&&

LAT...LON 3487 8283 3492 8289 3500 8288 3513 8252
      3489 8247
TIME...MOT...LOC 2305Z 254DEG 17KT 3496 8276 

HAIL...1.00IN
WIND...60MPH
 
$$

RM

What forecasters said that day

The local office's own words before this severe thunderstorm warning went out, 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 this severe thunderstorm warning went out at Mar 27, 2:58 PM EDT, 4 hours 7 minutes earlier.

Area forecast discussion, Mar 27, 2:58 PM EDT, 4 hours 7 minutes before
Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
258 PM EDT Sat Mar 27 2021

.SYNOPSIS...
A strong cold front will cross Tennessee tonight then cross
our area around midday to early afternoon Sunday.  This front will
be preceded by another round of thunderstorms.  Behind the front,
temperatures will return to normal as high pressure builds in for
Monday.  More unsettled weather looks to be in store for the region
by the middle of the week as another strong cold front reaches our
region from the northwest.

&&

.NEAR TERM /THROUGH SUNDAY/...
An active period is in store thru Sunday. Currently, a warm front is
working north across the FA and instigating stg to svr tstms across
the NC fthills and piedmont. These storms have become loosely
organized as a pockets of ulvl energy traverse the mean flow. A
Severe T-Storm Watch has been issued by the SPC thru 8 pm this
evening for areas north and west of Charlotte. The trailing srn edge
of this line is not as strong, but some enhanced activation is
anticipated later this evening as upper forcing increases from the
west and a warm front convg zone moves north. The hires models have
varying ideas with this scenario, however, with the 4km NAM
consistently producing less convection than the HRRR and WRF models.
In any case, still expect a good potential for high rainfall
producing storms this evening and again tomorrow ahead of a cold
front to generate new flash flooding and and perhaps exasperate the
current flooding conds. Thus, a Flash Flood Watch is in effect until
00z Mon.

There should be a lull in activity overnight as the main warm front
lifts north of the FA, but by mid-morning Sun, expect a strong
convective line approaching the FA from the west ahead of a cold
front. Some timing discrepancies are noted in the hires models with
the HRRR abt 6-8 hrs ahead of the 4km NAM. This would make a big
difference as to available sbCAPE, but for now, believe the pre-storm
environment will feature sbCAPE values on the order of 800-1200
J/kg. Shear levels will also begin to increase and the timing of the
strongest shear still looks to be a little quicker than the best
destabilization, but enuf overlap is anticipated for a line of
stg/svr organized storms beginning before noon and traversing east
thru the afternoon. The main threats will be damaging winds and
large hail, however, a few tornadoes are not out of the question as
well with right turning hodos noted in the model soundings while a
llvl jet increases. There could be another convective watch issued
by the SPC for tomorrow afternoon.

&&

.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
As of 230 PM EDT Saturday: High pressure will begin to build into
the area Sunday leading to more tranquil conditions through Monday
night. Moisture will begin to return to the area by Tuesday as the
high moves of the east coast and return flow sets up. Highs both
Monday and Tuesday will be in the 60s in the Piedmont and mountain
valleys.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
As of 230 pm EDT Saturday: A broad trof will dig into the middle of
the country for the middle of the week, shifting into the
northeastern states by late week. Expect showers and some
thunderstorms for our area Wednesday and Wednesday night. A cold
front will move through bringing much cooler conditions into the
area on Thursday and Friday.

Temperatures at or below freezing appear possible Friday morning
across the forecast area. Since the frost/freeze program will begin
again on April 1 for northeast Georgia, the SC foothills and
Piedmont and the southern NC foothills and Piedmont, headlines may
be needed Friday morning.

&&

.AVIATION /19Z SATURDAY THROUGH THURSDAY/...
At KCLT and elsewhere: Rounds of thunderstorms will affect the area
this afternoon and evening, mainly across the NC terminals. Flight
conds will occasionally go to MVFR/IFR with these cells then back to
VFR. A relatively lull in activity is anticipated overnight, then
another round of strong thunderstorms will cross the entire area
from the west ahead of a cold front. Expect continued flight
restrictions with this convection thru the period.

Outlook: VFR conds return Mon with a couple more moist systems and
flight restrictions possibly affecting the region as early as Tue.

Confidence Table...

            19-01Z        01-07Z        07-13Z        13-18Z
KCLT       High  97%     High  96%     High  87%     High  96%
KGSP       High  97%     High 100%     Med   79%     High  90%
KAVL       High  95%     High  86%     High  97%     High  81%
KHKY       High  94%     High  83%     Med   73%     High  81%
KGMU       High  99%     High 100%     High  92%     High  97%
KAND       High  99%     High 100%     High 100%     High  96%

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...None.
NC...Flash Flood Watch through Sunday evening for NCZ033-048>053-
     058-059-062>065-501-503-505-507-509.
SC...None.

&&

SYNOPSIS...DEO
NEAR TERM...SBK
SHORT TERM...SCW
LONG TERM...SCW
AVIATION...SBK
Hazardous weather outlook, Mar 27, 6:00 PM EDT, 1 hour 5 minutes before
Hazardous Weather Outlook
National Weather Service Greenville-Spartanburg SC
600 PM EDT Sat Mar 27 2021

GAZ010-017-018-026-028-029-NCZ035>037-056-057-068>072-082-502-504-
506-508-510-SCZ001>014-019-282200-
Rabun-Habersham-Stephens-Franklin-Hart-Elbert-Alexander-Iredell-
Davie-Catawba-Rowan-Cleveland-Lincoln-Gaston-Mecklenburg-Cabarrus-
Union NC-Greater Caldwell-Greater Burke-Eastern McDowell-
Greater Rutherford-Eastern Polk-Oconee Mountains-Pickens Mountains-
Greenville Mountains-Greater Oconee-Greater Pickens-
Greater Greenville-Spartanburg-Cherokee-York-Anderson-Abbeville-
Laurens-Union SC-Chester-Greenwood-
600 PM EDT Sat Mar 27 2021

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

.DAY ONE...Tonight.

Scattered thunderstorms are expected to impact the area, primarily
this evening. While the main threats with these storms will be from
cloud to ground lightning, gusty winds, and locally heavy rainfall, a
few storms could produce brief severe weather in the form of damaging
winds and large hail.

.DAYS TWO THROUGH SEVEN...Sunday through Friday.

A line of thunderstorms is expected to cross the area from west to
east during the late morning to mid-afternoon hours on Sunday.
Damaging winds will be the main threat, but a few storms may produce
large hail, as well.

.SPOTTER INFORMATION STATEMENT...

None.

NCZ033-048>053-058-059-062>065-501-503-505-507-509-282200-
Avery-Madison-Yancey-Mitchell-Swain-Haywood-Buncombe-Graham-
Northern Jackson-Macon-Southern Jackson-Transylvania-Henderson-
Caldwell Mountains-Burke Mountains-McDowell Mountains-
Rutherford Mountains-Polk Mountains-
600 PM EDT Sat Mar 27 2021

...FLASH FLOOD WATCH IN EFFECT THROUGH SUNDAY EVENING...

This Hazardous Weather Outlook is for western North 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.

   Flash Flood Watch.

In addition to the flooding threat, scattered thunderstorms remain
possible across the area tonight. The main threats with these storms
will be from cloud to ground lightning, gusty winds, and locally
heavy rainfall.

.DAYS TWO THROUGH SEVEN...Sunday through Friday.

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

   Flash Flood Watch.

A line of thunderstorms is expected to cross the area from west to
east during the late morning to mid-afternoon hours on Sunday.
Damaging winds will be the main threat, but a few storms may produce
large hail, as well.

.SPOTTER INFORMATION STATEMENT...

None.

Lane

In the hours before

Local storm report, Mar 27, 4:38 PM EDT, 2 hours 27 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
438 PM EDT SAT MAR 27 2021

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

0410 PM     HAIL             6 ENE HUNTERSVILLE      35.44N 80.74W
03/27/2021  E1.25 INCH       CABARRUS           NC   PUBLIC

            HALF DOLLAR SIZE HAIL.

&&

SBK
Local storm report, Mar 27, 4:40 PM EDT, 2 hours 25 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
440 PM EDT SAT MAR 27 2021

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

0439 PM     HAIL             1 WNW MOUNT PLEASANT    35.41N 80.46W
03/27/2021  E1.00 INCH       CABARRUS           NC   PUBLIC

            QUARTER SIZE HAIL.

&&

SBK
Special weather statement, Mar 27, 4:45 PM EDT, 2 hours 20 minutes before
Special Weather Statement
National Weather Service Greenville-Spartanburg SC
445 PM EDT Sat Mar 27 2021

SCZ007-008-013-272130-
Cherokee SC-Union SC-Spartanburg SC-
445 PM EDT Sat Mar 27 2021

...A STRONG THUNDERSTORM WITH INTENSE LIGHTNING WILL IMPACT CENTRAL
SPARTANBURG...SOUTHWESTERN CHEROKEE AND NORTHWESTERN UNION COUNTIES
UNTIL 530 PM EDT...

At 445 PM EDT, Doppler radar was tracking a strong thunderstorm with
intense lightning 6 miles southwest of Spartanburg, or near Roebuck,
moving east at 20 mph.

Locations to be impacted include...
Spartanburg, Pacolet, Cowpens, Roebuck, Pacolet Mills, Moore, Croft
State Park, Cedar Springs, Jonesville and Thicketty.

In addition to intense lightning, wind gusts up to 50 mph and nickel
size hail will be possible in these areas.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Frequent lightning is occurring with this storm. 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 storm approaches.

&&

LAT...LON 3479 8205 3497 8207 3505 8171 3478 8168
TIME...MOT...LOC 2045Z 264DEG 16KT 3489 8203

RM
Special weather statement, Mar 27, 5:04 PM EDT, 2 hours 1 minute before
Special Weather Statement
National Weather Service Greenville-Spartanburg SC
504 PM EDT Sat Mar 27 2021

NCZ071-082-SCZ009-272145-
Union NC-Mecklenburg NC-York SC-
504 PM EDT Sat Mar 27 2021

...STRONG THUNDERSTORMS WITH INTENSE LIGHTNING WILL IMPACT SOUTHERN
MECKLENBURG...NORTHERN UNION AND EAST CENTRAL YORK COUNTIES UNTIL 545
PM EDT...

At 503 PM EDT, Doppler radar indicated strong thunderstorms with
intense lightning along a line extending from 15 miles northeast of
Monroe to 6 miles northwest of Indian Land, and moving east at 35
mph.

Locations to be impacted include...
Monroe, South Charlotte, Matthews, Indian Trail, Weddington,
Stallings, Unionville, Pineville, Lake Park and Hemby Bridge.

In addition to intense lightning, wind gusts up to 45 mph and dime
size hail will be possible in these areas.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Torrential rainfall may flood areas with poor drainage, such as
ditches and underpasses. Avoid these areas and do not cross flooded
roads. Water levels of small streams may also rise rapidly. Seek
higher ground if threatened by flood waters.

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 3508 8029 3501 8065 3504 8088 3508 8091
      3506 8090 3504 8091 3507 8111 3520 8054
      3518 8050 3518 8048 3517 8047 3516 8044
      3517 8042 3517 8039 3518 8037 3517 8036
      3519 8028
TIME...MOT...LOC 2103Z 265DEG 66KT 3518 8039 3505 8096

RM
Special weather statement, Mar 27, 5:45 PM EDT, 1 hour 20 minutes before
Special Weather Statement
National Weather Service Greenville-Spartanburg SC
545 PM EDT Sat Mar 27 2021

GAZ028-029-272230-
Elbert GA-Hart GA-
545 PM EDT Sat Mar 27 2021

...A STRONG THUNDERSTORM WITH INTENSE LIGHTNING WILL IMPACT
NORTHWESTERN ELBERT AND SOUTHWESTERN HART COUNTIES UNTIL 630 PM
EDT...

At 545 PM EDT, Doppler radar was tracking a strong thunderstorm with
intense lightning near Danielsville, or near Colbert, moving east at
20 mph.

Locations to be impacted include...
Elberton, Bowman, Dewy Rose, Sweet City, Nuberg and Vanna.

In addition to intense lightning, wind gusts up to 40 mph and pea
size hail will be possible in these areas.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Frequent lightning is occurring with this storm. 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 storm approaches.

&&

LAT...LON 3405 8299 3408 8300 3408 8301 3410 8304
      3411 8303 3412 8305 3415 8306 3417 8310
      3419 8309 3420 8309 3423 8308 3425 8311
      3433 8292 3408 8281 3404 8297
TIME...MOT...LOC 2145Z 249DEG 17KT 3408 8324

RM
Special weather statement, Mar 27, 6:55 PM EDT, 10 minutes before
Special Weather Statement
National Weather Service Greenville-Spartanburg SC
655 PM EDT Sat Mar 27 2021

SCZ001>003-005-006-272345-
Pickens Mountains SC-Greater Pickens SC-Oconee Mountains SC-
Greenville Mountains SC-Greater Greenville SC-
655 PM EDT Sat Mar 27 2021

...A STRONG THUNDERSTORM WITH INTENSE LIGHTNING WILL IMPACT
NORTHWESTERN GREENVILLE...PICKENS AND NORTHEASTERN OCONEE COUNTIES
UNTIL 745 PM EDT...

At 655 PM EDT, Doppler radar was tracking a strong thunderstorm with
intense lightning 8 miles northwest of Pickens, or near Jocassee
Gorges, moving east at 20 mph.

Locations to be impacted include...
Pickens, Slater-Marietta, Lake Keowee, Jocassee Gorges, Jones Gap
State Park, Lake Jocassee, Devils Fork State Park, Keowee Toxaway
State Park, Table Rock State Park and Furman University.

In addition to intense lightning, wind gusts up to 45 mph and half
inch hail will be possible in these areas.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Frequent lightning is occurring with this storm. 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 storm approaches.

&&

LAT...LON 3498 8299 3507 8278 3507 8275 3508 8275
      3508 8274 3510 8270 3511 8269 3514 8261
      3515 8257 3516 8255 3516 8254 3491 8242
      3480 8289 3481 8289 3481 8290 3479 8292
TIME...MOT...LOC 2255Z 250DEG 19KT 3494 8284

RM

The office that day

Everything else NWS Greenville-Spartanburg, SC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Mar 27, 3:24 PM EDTSpecial Weather StatementGSPCherokee51 min
Mar 27, 3:53 PM EDTSpecial Weather StatementGSPYork52 min
Mar 27, 4:45 PM EDTSpecial Weather StatementGSPSpartanburg45 min
Mar 27, 6:55 PM EDTSpecial Weather StatementGSPPickens50 min
Mar 27, 7:10 PM EDTSpecial Weather StatementGSPGreenville35 min
Mar 27, 7:11 PM EDTSpecial Weather StatementGSPAbbeville34 min
Mar 27, 7:35 PM EDTSpecial Weather StatementGSPGreenville25 min

Nearby

Severe Thunderstorm Warnings in South Carolina, 2021Every severe thunderstorm warning in 2021

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.