Alert archive / South Carolina / Severe Thunderstorm Warnings in 2020

Severe Thunderstorm Warning 21, NWS Charleston, SC

April 13, 2020Berkeley County, Charleston County, South Carolina

NWS Charleston, SC issued this severe thunderstorm warning at Apr 13, 2020, 8:42 AM EDT for Berkeley County, Charleston County, South Carolina. It was in force for 33 min. 2 reports 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
Apr 13, 2020, 8:42 AM EDT (12:42 UTC)
Expired
Apr 13, 2020, 9:15 AM EDT
In force
33 min
Issued by
NWS Charleston, SC
Area
Storm-based polygon
Hail
0.75 in
Wind
70.0 mph

Counties Berkeley County, SC, Charleston County, SC

The radar

The Charleston,SC radar (KCLX), 142 km from the middle of the area, began a volume at 12:43 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
Apr 13, 8:51 AM EDTTSTM WND DMG5 Se Cainhoy, SCTREE SNAPPED AND FELL ON CAR IN CLASSIC COURT.
Apr 13, 9:04 AM EDTMARINE TSTM WIND 481 E Sullivans Island, SCSULLIVANS ISLAND WXFLOW GUSTED TO 42 KT.

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

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

IssuedProductOfficeLasted
Apr 13, 3:20 AM EDTTornado WatchSPC8 hr

The nearest sounding before it

Charleston AFB, SC (KCHS), launched 12:00Z, 0.7 hours before the alert went out and 41 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 2020-04-13Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 943 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 2020-04-13The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 475 square meters per square second.1939587897117Sfc1 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
943 J/kg
Mixed-layer CIN
-37 J/kg
Mixed-layer LCL
698 m above ground
0-6 km bulk shear
74 kt
0-1 km storm-relative helicity
475 m²/s²
0-3 km storm-relative helicity
509 m²/s²
Significant tornado parameter
3.2
Supercell composite
14.1

Open this sounding in Storm Lab

The text

As transmitted.

013 
WUUS52 KCHS 131242
SVRCHS
SCC015-019-131315-
/O.NEW.KCHS.SV.W.0021.200413T1242Z-200413T1315Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Charleston SC
842 AM EDT Mon Apr 13 2020

The National Weather Service in Charleston has issued a

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

* Until 915 AM EDT.

* At 842 AM EDT, severe thunderstorms were located along a line
  extending from near Naval Weapons Station Charleston to 6 miles
  south of Folly Beach, moving east at 50 mph.

  HAZARD...70 mph wind gusts and penny size hail.

  SOURCE...Law enforcement.

  IMPACT...Expect considerable tree damage. Damage is likely to 
           mobile homes, roofs, and outbuildings.

* Locations impacted include...
  North Charleston, Mount Pleasant, Goose Creek, Hanahan,
  McClellanville, Downtown Charleston, Daniel Island, Fort Sumter,
  James Island, West Ashley, Johns Island, Isle Of Palms, Folly
  Beach, Sullivan's Island and Kiawah Island.

This warning includes...
 I-26 between mile markers 216 and 221.
 I-526 between mile markers 21 and 31.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A tornado watch remains in effect for the warned area. Tornadoes can
develop quickly from severe thunderstorms. Although a tornado is not
immediately likely, if one is spotted, act quickly and move to a
place of safety inside a sturdy structure such as a basement or small
interior room.

This is a DANGEROUS SITUATION. These storms are producing widespread 
wind damage across the area. SEEK SHELTER NOW inside a sturdy 
structure and stay away from windows! Report damage directly to the 
Charleston National Weather Service at 1-888-383-2024 when it is 
safe to do so.

&&

LAT...LON 3307 7931 3299 7933 3298 7951 3288 7955
      3274 7983 3267 7986 3259 7997 3257 8004
      3294 7998 3324 7951 3324 7946 3316 7937
      3314 7927 3310 7927
TIME...MOT...LOC 1242Z 260DEG 43KT 3296 7990 3256 7993 

HAIL...0.75IN
WIND...70MPH
 
$$
2 follow-up statements
080 
WWUS52 KCHS 131301
SVSCHS

Severe Weather Statement
National Weather Service Charleston SC
901 AM EDT Mon Apr 13 2020

SCC015-019-131315-
/O.CON.KCHS.SV.W.0021.000000T0000Z-200413T1315Z/
Charleston SC-Berkeley SC-
901 AM EDT Mon Apr 13 2020

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 915 AM EDT
FOR CHARLESTON AND BERKELEY COUNTIES...

At 901 AM EDT, severe thunderstorms were located along a line
extending from near Awendaw to 14 miles southeast of Isle Of Palms,
moving east at 50 mph.

HAZARD...70 mph wind gusts and penny size hail.

SOURCE...Law enforcement.

IMPACT...Expect considerable tree damage. Damage is likely to mobile 
         homes, roofs, and outbuildings.

Locations impacted include...
Mount Pleasant, McClellanville, Isle Of Palms, Awendaw, Garris
Landing, Hampton Plantation State Park, Price Inlet, Bull Island,
Capers Inlet, Santee Coastal Reserve, Cape Island, Lighthouse Island
and Cape Romain.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A tornado watch remains in effect for the warned area. Tornadoes can
develop quickly from severe thunderstorms. Although a tornado is not
immediately likely, if one is spotted act quickly and move to a place
of safety inside a sturdy structure, such as a basement or small
interior room.

This is a DANGEROUS SITUATION. These storms are producing widespread 
wind damage across this area. SEEK SHELTER NOW inside a sturdy 
structure and stay away from windows.
 
Report damage directly to the Charleston National Weather Service at
1-888-383-2024 when it is safe to do so.

&&

LAT...LON 3307 7931 3299 7933 3298 7951 3288 7955
      3277 7977 3281 7979 3287 7979 3297 7975
      3306 7977 3324 7951 3324 7946 3322 7945
      3316 7937 3314 7927 3310 7927
TIME...MOT...LOC 1301Z 260DEG 43KT 3300 7965 3260 7968 

HAIL...0.75IN
WIND...70MPH
 
$$
324 
WWUS52 KCHS 131310
SVSCHS

Severe Weather Statement
National Weather Service Charleston SC
910 AM EDT Mon Apr 13 2020

SCC015-019-131320-
/O.EXP.KCHS.SV.W.0021.000000T0000Z-200413T1315Z/
Charleston SC-Berkeley SC-
910 AM EDT Mon Apr 13 2020

...THE SEVERE THUNDERSTORM WARNING FOR CHARLESTON AND BERKELEY
COUNTIES WILL EXPIRE AT 915 AM EDT...
        
The storms which prompted the warning have moved out of the area.
Therefore the warning will be allowed to expire.

LAT...LON 3307 7931 3299 7933 3298 7951 3288 7955
      3277 7977 3281 7979 3287 7979 3297 7975
      3306 7977 3324 7951 3324 7946 3322 7945
      3316 7937 3314 7927 3310 7927
TIME...MOT...LOC 1310Z 260DEG 43KT 3302 7953 3262 7956 

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Apr 12, 10:23 PM EDTCoastal Flood AdvisoryCHS4 hr
Apr 13, 5:33 AM EDTSevere Thunderstorm WarningCHSAllendale, Hampton, Jasper57 min
Apr 13, 5:54 AM EDTTornado WarningCHSAllendale, Hampton36 min
Apr 13, 6:02 AM EDTTornado WarningCHSAllendale14 min
Apr 13, 6:18 AM EDTTornado Warning Tornado observedCHSColleton, Hampton27 min
Apr 13, 6:22 AM EDTSevere Thunderstorm WarningCHSBeaufort, Colleton, Dorchester, Hampton, Jasper53 min
Apr 13, 6:38 AM EDTTornado Warning EmergencyTornado observedCHSColleton, Hampton37 min
Apr 13, 6:53 AM EDTSevere Thunderstorm WarningCHSBeaufort, Berkeley, Charleston, Colleton, Dorchester52 min
Apr 13, 7:01 AM EDTTornado Warning Tornado observedConsiderable damage threatCHSColleton, Dorchester29 min
Apr 13, 7:08 AM EDTSevere Thunderstorm WarningCHSBeaufort, Jasper67 min
Apr 13, 7:15 AM EDTSevere Thunderstorm WarningCHSJasper60 min
Apr 13, 7:26 AM EDTTornado WarningCHSBerkeley, Dorchester34 min
Apr 13, 7:42 AM EDTSevere Thunderstorm WarningCHSBeaufort, Berkeley, Charleston, Colleton, Dorchester63 min
Apr 13, 7:47 AM EDTSpecial Marine WarningCHS88 min
Apr 13, 7:50 AM EDTSpecial Marine WarningCHS115 min
Apr 13, 7:54 AM EDTTornado Warning Tornado observedCHSBerkeley18 min
Apr 13, 8:00 AM EDTTornado WarningCHSCharleston, Colleton30 min
Apr 13, 8:13 AM EDTSevere Thunderstorm WarningCHSBeaufort, Jasper62 min
Apr 13, 8:26 AM EDTTornado WarningCHSCharleston34 min
Apr 13, 9:06 AM EDTSpecial Marine WarningCHS54 min
Apr 13, 9:38 AM EDTSpecial Marine WarningCHS86 min
Apr 13, 9:41 AM EDTSpecial Marine WarningCHS82 min
Apr 13, 9:53 AM EDTSmall Craft AdvisoryCHS17 hr

Nearby

Severe Thunderstorm Warnings in South Carolina, 2020Every severe thunderstorm warning in 2020

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.