Alert archive / South Carolina / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 74, NWS Columbia, SC

August 17, 2021Aiken County, South Carolina

NWS Columbia, SC issued this severe thunderstorm warning at Aug 17, 2021, 8:40 PM EDT for Aiken County, South Carolina. It was in force for 50 min. 1 report came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued
Aug 17, 2021, 8:40 PM EDT (00:40 UTC)
Expired
Aug 17, 2021, 9:30 PM EDT
In force
50 min
Issued by
NWS Columbia, SC
Area
Storm-based polygon
Hail
0.75 in
Wind
60.0 mph

County Aiken County, SC

The radar

The Columbia radar (KCAE), 52 km from the middle of the area, began a volume at 00:41 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.

What was reported inside it

TimeReportWhereRemark
Aug 17, 9:01 PM EDTTSTM WND DMG9 N Windsor, SCSC HIGHWAY PATROL REPORTED TREE DOWN IN ROADWAY AT FLOWING WELL ROAD AND COLEMAN BRIDGE ROAD. TIME ESTIMATED BY RADAR.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Charleston AFB, SC (KCHS), launched 00:00Z, 0.7 hours before the alert went out and 164 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, Charleston AFB, SC at 00:00Z on 2021-08-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1990 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Charleston AFB, SC at 00:00Z on 2021-08-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 61 square meters per square second.1939Sfc1 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
1990 J/kg
Mixed-layer CIN
-1 J/kg
Mixed-layer LCL
710 m above ground
0-6 km bulk shear
17 kt
0-1 km storm-relative helicity
61 m²/s²
0-3 km storm-relative helicity
71 m²/s²
Significant tornado parameter
0.0
Supercell composite
2.0

Open this sounding in Storm Lab

The text

As transmitted.

512 
WUUS52 KCAE 180040
SVRCAE
SCC003-180130-
/O.NEW.KCAE.SV.W.0074.210818T0040Z-210818T0130Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Columbia SC
840 PM EDT Tue Aug 17 2021

The National Weather Service in Columbia has issued a

* Severe Thunderstorm Warning for...
  Aiken County in central South Carolina...

* Until 930 PM EDT.

* At 840 PM EDT, a severe thunderstorm was located over New Ellenton,
  or near Aiken Mall, moving northeast at 35 mph.

  HAZARD...60 mph wind gusts.

  SOURCE...Radar indicated.

  IMPACT...Expect damage to roofs, siding, and trees.

* Locations impacted include...
  Aiken, Aiken Mall, New Ellenton, USC Aiken, Citizens Park, Aiken
  Municipal Airport, Gloverville, Aiken State Park, Graniteville,
  Burnettown, Wagener, Perry, Windsor, Perry Airport, Hopeland
  Gardens, Savannah River Site Badge Office, Boyd Pond Park, Vaucluse
  and New Holland.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of 
a building.

&&

LAT...LON 3332 8176 3343 8186 3361 8184 3386 8155
      3381 8151 3380 8146 3377 8143 3374 8143
      3373 8141 3373 8136 3370 8127 3368 8125
      3339 8157
TIME...MOT...LOC 0040Z 219DEG 29KT 3343 8172 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

CJR
2 follow-up statements
487 
WWUS52 KCAE 180121
SVSCAE

Severe Weather Statement
National Weather Service Columbia SC
921 PM EDT Tue Aug 17 2021

SCC003-180130-
/O.CON.KCAE.SV.W.0074.000000T0000Z-210818T0130Z/
Aiken SC-
921 PM EDT Tue Aug 17 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 930 PM EDT
FOR NORTHEASTERN AIKEN COUNTY...

At 919 PM EDT, a severe thunderstorm was located 9 miles north of
Aiken State Park, or 15 miles south of Batesburg-Leesville, moving 
northeast at 30 mph. SC DOT reports downed trees about 8 miles SW of 
Wagener.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

IMPACT...Expect damage to roofs, siding, and trees.

Locations impacted include...
Aiken State Park, Wagener, Perry, Perry Airport and New Holland. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of 
a building.

&&

LAT...LON 3386 8155 3381 8151 3380 8146 3377 8143
      3374 8143 3373 8141 3373 8136 3370 8127
      3368 8125 3349 8145 3373 8170
TIME...MOT...LOC 0119Z 220DEG 27KT 3369 8147 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...OBSERVED
MAX WIND GUST...60 MPH

$$

CJR
603 
WWUS52 KCAE 180128
SVSCAE

Severe Weather Statement
National Weather Service Columbia SC
928 PM EDT Tue Aug 17 2021

SCC003-180138-
/O.EXP.KCAE.SV.W.0074.000000T0000Z-210818T0130Z/
Aiken SC-
928 PM EDT Tue Aug 17 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN AIKEN COUNTY WILL
EXPIRE AT 930 PM EDT...
                
The storm which prompted the warning has weakened below severe
limits, and no longer poses an immediate threat to life or property.
Therefore, the warning will be allowed to expire.

A Tornado Watch remains in effect until 200 AM EDT for central South
Carolina.

LAT...LON 3386 8155 3381 8151 3380 8146 3377 8143
      3374 8143 3373 8141 3373 8136 3370 8127
      3368 8125 3349 8145 3373 8170
TIME...MOT...LOC 0128Z 219DEG 29KT 3374 8142 

$$

CJR

The office that day

Everything else NWS Columbia, SC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 17, 8:18 PM EDTSpecial Weather StatementCAESaluda42 min
Aug 17, 8:22 PM EDTSpecial Weather StatementCAEAiken53 min
Aug 17, 8:43 PM EDTTornado WarningCAELexington, Saluda32 min
Aug 17, 9:18 PM EDTSpecial Weather StatementCAEFairfield, Lexington42 min
Aug 17, 10:58 PM EDTAreal Flood AdvisoryCAECalhoun, Lexington, Richland2 hr
Aug 17, 11:45 PM EDTFlash Flood WarningCAELexington, Richland2 hr

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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.