Alert archive / South Carolina / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 42, NWS Charleston, SC

July 18, 2021Beaufort County, Colleton County, South Carolina

NWS Charleston, SC issued this severe thunderstorm warning at Jul 18, 2021, 3:04 PM EDT for Beaufort County, Colleton County, South Carolina. It was in force for 41 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
Jul 18, 2021, 3:04 PM EDT (19:04 UTC)
Expired
Jul 18, 2021, 3:45 PM EDT
In force
41 min
Issued by
NWS Charleston, SC
Area
Storm-based polygon
Hail
0.88 in
Wind
60.0 mph

Counties Beaufort County, SC, Colleton County, SC

The radar

The Charleston,SC radar (KCLX), 57 km from the middle of the area, began a volume at 19:08 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.

The nearest sounding before it

Charleston AFB, SC (KCHS), launched 12:00Z, 7.1 hours before the alert went out and 44 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 12:00Z on 2021-07-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 962 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 12:00Z on 2021-07-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 73 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
962 J/kg
Mixed-layer CIN
-70 J/kg
Mixed-layer LCL
983 m above ground
0-6 km bulk shear
16 kt
0-1 km storm-relative helicity
73 m²/s²
0-3 km storm-relative helicity
100 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

234 
WUUS52 KCHS 181904
SVRCHS
SCC013-029-181945-
/O.NEW.KCHS.SV.W.0042.210718T1904Z-210718T1945Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Charleston SC
304 PM EDT Sun Jul 18 2021

The National Weather Service in Charleston has issued a

* Severe Thunderstorm Warning for portions of...
  Beaufort County in southeastern South Carolina...
  Colleton County in southeastern South Carolina...

* Until 345 PM EDT.

* At 304 PM EDT, severe thunderstorms were located along a line
  extending from near White Hall to near Clarendon, moving northeast
  at 20 mph.

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

  SOURCE...Radar indicated.

  IMPACT...Expect damage to trees and powerlines.

* Locations impacted include...
  Cottageville, Green Pond, Dale, Gardens Corner, Jacksonboro,
  Ashepoo, Ritter and White Hall.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Report damage directly to the Charleston National Weather Service at
888-383-2024 when it is safe to do so.

&&

LAT...LON 3293 8040 3291 8041 3289 8039 3287 8040
      3284 8039 3281 8040 3279 8043 3274 8045
      3270 8041 3267 8042 3248 8080 3278 8073
      3297 8042
TIME...MOT...LOC 1904Z 228DEG 19KT 3276 8068 3252 8076 

HAIL...0.88IN
WIND...60MPH
 
$$

MTE
2 follow-up statements
530 
WWUS52 KCHS 181933
SVSCHS

Severe Weather Statement
National Weather Service Charleston SC
333 PM EDT Sun Jul 18 2021

SCC013-181942-
/O.CAN.KCHS.SV.W.0042.000000T0000Z-210718T1945Z/
Beaufort SC-
333 PM EDT Sun Jul 18 2021

...THE SEVERE THUNDERSTORM WARNING FOR BEAUFORT COUNTY IS
CANCELLED...
    
The immediate risk for severe weather has ended. 

LAT...LON 3289 8039 3287 8040 3284 8039 3274 8045
      3271 8042 3267 8042 3258 8060 3259 8061
      3258 8062 3261 8066 3263 8066 3263 8067
      3264 8066 3265 8068 3267 8068 3268 8075
      3278 8073 3297 8042
TIME...MOT...LOC 1932Z 245DEG 14KT 3273 8062 

$$

SCC029-181945-
/O.CON.KCHS.SV.W.0042.000000T0000Z-210718T1945Z/
Colleton SC-
333 PM EDT Sun Jul 18 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 345 PM EDT
FOR COLLETON COUNTY...

At 332 PM EDT, a severe thunderstorm was located over Green Pond,
moving northeast at 15 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

IMPACT...Expect damage to trees and powerlines.

Locations impacted include...
Cottageville, Jacksonboro, Ashepoo, Green Pond, Ritter and White
Hall.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Report damage directly to the Charleston National Weather Service at
888-383-2024 when it is safe to do so.

&&

LAT...LON 3289 8039 3287 8040 3284 8039 3274 8045
      3271 8042 3267 8042 3258 8060 3259 8061
      3258 8062 3261 8066 3263 8066 3263 8067
      3264 8066 3265 8068 3267 8068 3268 8075
      3278 8073 3297 8042
TIME...MOT...LOC 1932Z 245DEG 14KT 3273 8062 

HAIL...<.75IN
WIND...60MPH
 
$$
252 
WWUS52 KCHS 181943
SVSCHS

Severe Weather Statement
National Weather Service Charleston SC
343 PM EDT Sun Jul 18 2021

SCC029-181953-
/O.EXP.KCHS.SV.W.0042.000000T0000Z-210718T1945Z/
Colleton SC-
343 PM EDT Sun Jul 18 2021

...THE SEVERE THUNDERSTORM WARNING FOR PORTIONS OF COLLETON COUNTY
WILL EXPIRE AT 345 PM EDT...
                
The storm which prompted the warning has weakened below severe
limits, and no longer pose an immediate threat to life or property.
Therefore the warning will be allowed to expire.

LAT...LON 3289 8039 3287 8040 3284 8039 3274 8045
      3271 8042 3267 8042 3258 8060 3259 8061
      3258 8062 3261 8066 3263 8066 3263 8067
      3264 8066 3265 8068 3267 8068 3268 8075
      3278 8073 3297 8042
TIME...MOT...LOC 1943Z 228DEG 19KT 3277 8057 

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 18, 12:17 PM EDTSevere Thunderstorm WarningCHSAllendale43 min
Jul 18, 1:29 PM EDTSpecial Weather StatementCHSBamberg31 min
Jul 18, 2:11 PM EDTSpecial Weather StatementCHSBerkeley34 min
Jul 18, 2:49 PM EDTSpecial Weather StatementCHSJasper26 min
Jul 18, 3:09 PM EDTSevere Thunderstorm WarningCHSJasper55 min
Jul 18, 3:17 PM EDTSpecial Weather StatementCHSBerkeley28 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.