Alert archive / South Carolina / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 23, NWS Charleston, SC

May 4, 2021Berkeley County, South Carolina

NWS Charleston, SC issued this severe thunderstorm warning at May 4, 2021, 4:30 PM EDT for Berkeley County, South Carolina. It was in force for 20 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
May 4, 2021, 4:30 PM EDT (20:30 UTC)
Expired
May 4, 2021, 4:50 PM EDT
In force
20 min
Issued by
NWS Charleston, SC
Area
Storm-based polygon
Hail
0.88 in
Wind
60.0 mph

County Berkeley County, SC

The radar

The Wilmington radar (KLTX), 140 km from the middle of the area, began a volume at 20:33 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
May 4, 4:33 PM EDTHAIL 1.254 Nw Huger, SCSOCIAL MEDIA REPORT OF QUARTER TO HALF DOLLAR SIZE HAIL. REPORT RELAYED BY LOCAL NEWS STATION. TIME ESTIMATED FROM 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 12:00Z, 8.5 hours before the alert went out and 49 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 2021-05-04Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 573 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 2021-05-04The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 68 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
573 J/kg
Mixed-layer CIN
-149 J/kg
Mixed-layer LCL
1000 m above ground
0-6 km bulk shear
37 kt
0-1 km storm-relative helicity
68 m²/s²
0-3 km storm-relative helicity
48 m²/s²
Significant tornado parameter
0.1
Supercell composite
1.0

Open this sounding in Storm Lab

The text

As transmitted.

501 
WUUS52 KCHS 042030
SVRCHS
SCC015-042130-
/O.NEW.KCHS.SV.W.0023.210504T2030Z-210504T2130Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Charleston SC
430 PM EDT Tue May 4 2021

The National Weather Service in Charleston has issued a

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

* Until 530 PM EDT.

* At 430 PM EDT, severe thunderstorms were located along a line
  extending from 6 miles north of Crowfield Plantation to near Huger,
  moving northeast at 30 mph.

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

  SOURCE...Radar indicated.

  IMPACT...Expect damage to trees and powerlines.

* Locations impacted include...
  Moncks Corner, Jamestown, Old Santee Canal State Park and Huger. 

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 3321 7947 3315 7954 3316 7956 3313 7960
      3313 7964 3309 7966 3304 7972 3320 8003
      3335 7977 3332 7974 3332 7970 3330 7966
      3327 7956 3325 7953 3324 7946 3321 7945
TIME...MOT...LOC 2030Z 235DEG 25KT 3310 8005 3306 7982 

HAIL...0.88IN
WIND...60MPH
 
$$
2 follow-up statements
715 
WWUS52 KCHS 042041
SVSCHS

Severe Weather Statement
National Weather Service Charleston SC
441 PM EDT Tue May 4 2021

SCC015-042130-
/O.CON.KCHS.SV.W.0023.000000T0000Z-210504T2130Z/
Berkeley SC-
441 PM EDT Tue May 4 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 530 PM EDT
FOR BERKELEY COUNTY...

At 441 PM EDT, severe thunderstorms were located along a line
extending from near Old Santee Canal State Park to near Huger, moving
northeast at 45 mph.

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

SOURCE...Radar indicated.

IMPACT...Expect damage to trees and powerlines.

Locations impacted include...
Moncks Corner, Jamestown, Old Santee Canal State Park and Huger. 

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 3321 7947 3315 7954 3316 7956 3313 7960
      3313 7964 3309 7966 3304 7972 3318 7999
      3335 7977 3332 7974 3332 7970 3330 7966
      3327 7956 3325 7953 3324 7946 3321 7945
TIME...MOT...LOC 2041Z 242DEG 37KT 3315 7993 3310 7970 

HAIL...0.75IN
WIND...60MPH
 
$$
268 
WWUS52 KCHS 042050
SVSCHS

Severe Weather Statement
National Weather Service Charleston SC
450 PM EDT Tue May 4 2021

SCC015-042100-
/O.CAN.KCHS.SV.W.0023.000000T0000Z-210504T2130Z/
Berkeley SC-
450 PM EDT Tue May 4 2021

...THE SEVERE THUNDERSTORM WARNING FOR BERKELEY COUNTY IS
CANCELLED...
                
The storms which prompted the warning have weakened below severe
limits, and no longer pose an immediate threat to life or property.
Therefore the warning has been cancelled.  However small hail and
gusty winds 45 to 55 mph are still possible with these thunderstorms.

LAT...LON 3321 7947 3315 7954 3316 7956 3313 7960
      3313 7964 3309 7966 3304 7972 3318 7999
      3335 7977 3332 7974 3332 7970 3330 7966
      3327 7956 3325 7953 3324 7946 3321 7945
TIME...MOT...LOC 2049Z 235DEG 25KT 3319 7987 3314 7964 

$$

The office that day

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

IssuedProductOfficeCountiesLasted
May 3, 8:15 PM EDTAreal Flood AdvisoryCHSAllendale, Berkeley, Colleton, Dorchester, Hampton2 hr
May 3, 8:26 PM EDTSevere Thunderstorm WarningCHSBerkeley, Charleston38 min
May 3, 9:15 PM EDTSpecial Marine WarningCHS60 min
May 3, 10:00 PM EDTSpecial Marine WarningCHS2 hr
May 4, 3:38 PM EDTSpecial Weather StatementCHSCharleston37 min
May 4, 4:08 PM EDTSpecial Weather StatementCHSBerkeley37 min
May 4, 4:15 PM EDTSevere Thunderstorm WarningCHSBerkeley25 min
May 4, 4:32 PM EDTSpecial Weather StatementCHSDorchester28 min
May 4, 6:11 PM EDTSpecial Weather StatementCHSColleton49 min
May 4, 6:17 PM EDTSevere Thunderstorm WarningCHSBerkeley, Charleston, Colleton, Dorchester58 min
May 4, 6:59 PM EDTSevere Thunderstorm WarningCHSColleton, Dorchester46 min
May 4, 7:07 PM EDTSpecial Weather StatementCHSBerkeley38 min
May 4, 7:40 PM EDTSpecial Weather StatementCHSBerkeley, Dorchester35 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.