EF1 tornado, Sniders Xrds to Cottageville, South Carolina, April 13, 2020

1. EF065 to 85 mph

   Light damage. Surface peeled off some roofs, gutters and siding damaged, branches broken, shallow-rooted trees pushed over.

2. EF186 to 110 mphthis tornado

   Moderate damage. Roofs badly stripped, mobile homes overturned or badly damaged, exterior doors lost, windows broken.

3. EF2111 to 135 mph

   Considerable damage. Roofs torn off well-built houses, frame homes shifted on their foundations, mobile homes destroyed, large trees snapped or uprooted, cars lifted off the ground.

4. EF3136 to 165 mph

   Severe damage. Whole stories of well-built houses destroyed, large buildings badly damaged, trains overturned, trees debarked, heavy cars lifted and thrown.

5. EF4166 to 200 mph

   Devastating damage. Well-built houses leveled, structures with weak foundations moved some distance, cars thrown and large missiles generated.

6. EF5over 200 mph

   Incredible damage. Strong frame houses swept off their foundations, car-sized missiles thrown more than 100 meters, steel-reinforced concrete badly damaged, high-rise buildings deformed.

7. Unrated

   The survey recorded a tornado but could not put a number on it, most often because it crossed open country and damaged nothing a rating can be read from.

Rating

EF1

Date

April 13, 2020

Touchdown

6:46 AM EDT (10:46 UTC)

Lifted

6:50 AM EDT (10:50 UTC)

On the ground

4 minutes

Path length

3.1 miles (5.1 km)

Path width

100 yards (91 m)

Deaths

0

Injuries

0

County

Colleton County

Touchdown point

32.877, -80.746

Lift-off point

32.910, -80.709

Record number

2004130446-01

4 damage points were recorded along this path by NWS CHS, in the Damage Assessment Toolkit the survey teams carry. The strongest indicator was rated EF1. The highest wind the damage implies is 104 mph.

Survey points are preliminary and are the raw material the published rating was built from. Source: NWS Damage Assessment Toolkit.

A severe quasi-linear convective system (QLCS) moved through southeast South Carolina during the early morning hours of April 13, 2020 ahead of an approaching cold front. The environment ahead of the QLCS was unusually unstable for this time of day and year, with gulf moisture spreading upper 60 F to near 70 F dewpoints into a warm sector across the Southeast United States and mid level lapse rates around 7 C/km helping produce mixed layer convective available potential energy (MLCAPE) as high as 2000 J/kg across Southeast South Carolina. Within the warm sector, very strong vertical shear associated with a 50 knot plus low and mid-level jet, effective bulk shear around 70 knots, effective storm relative helicity in the 400-600 m2/s2 range, and VAD wind profiles displaying large, curved low-level hodographs were supportive of well organized convection and potentially embedded supercell thunderstorms in a QLCS capable of producing a prolonged path of damaging winds and strong long-track tornadoes. As the QLCS swept through Southeast South Carolina, a few supercell thunderstorms became exceptionally strong while partially breaking away from the main line of thunderstorms, producing widespread wind damage and strong long-track tornadoes. ||A total of 13 confirmed tornadoes occurred across Southeast South Carolina, including a long track EF-4 tornado in Hampton County that took the lives of 5 people and injured 60 others along an approximately 24 mile path. The EF-4 tornado was the first to have occurred across Southeast South Carolina and the last to have occurred in the entire state of South Carolina since November 17, 1995, almost 25 years prior. This particular tornado was associated with a storm that produced a destructive path of straight-line wind damage and series of long track and intermittent tornadoes for over 150 miles, beginning in Screven County, Georgia, then continuing northeast across Hampton County, Colleton County, Dorchester County, and Berkeley County, South Carolina before leaving the area and eventually shifting offshore along the South Carolina coast. Two other storms were responsible for the remaining tornadoes across the area, most of which occurred from a single storm occurring across Edisto Island, Seabrook Island and Kiawah Island. Outside the EF-4 tornado in Hampton County, straight-line winds near a passing tornado claimed the life of one individual and injured one in Colleton County, while another tornado caused 6 injuries across Berkeley County.

A National Weather Service Storm Survey Team confirmed an EF-1 tornado with an estimated maximum wind speed of 90 mph in southwest Colleton County. The tornado formed just west of Route 21 in southwest Colleton County, then traveled northeast before dissipating near Cane Branch Road. The tornado snapped off a couple dozen pine trees and broke off some tree branches along the path.

A National Weather Service Storm Survey Team confirmed an EF-1 tornado with an estimated maximum wind speed of 105 mph about 5 miles west-southwest of Walterboro, South Carolina. The tornado formed along Route 63 west of Interstate 95 and traveled northeast, eventually crossing over Ulmer Lake Drive and Beach Road before dissipating near the Ashepoo River and Jones Swamp Creek just west of Interstate 95. The tornado produced extensive tree damage in the vicinity of Beach Road. Hundreds of trees were snapped off or uprooted along the tornado path.

A National Weather Service Storm Survey Team confirmed an EF-1 tornado with an estimated maximum wind speed of 110 mph near Walterboro, South Carolina. The tornado formed near Route 63 about 4 miles southwest of Walterboro. This tornado grew in size as it tracked through Walterboro, then continued northeast through the Low Country Regional Airport, before remaining about 1 mile west-northwest of Highway 17, sporadically touching down between Sidneys Road to Red Oak Road. The tornado then dissipated just northeast of Cottageville, South Carolina. ||This tornado produced extensive tree damage along the path across northwestern portions of Walterboro with many hundreds of trees snapped off or uprooted. Trees falling on houses or winds associated with the tornado produced mainly minor damage to hundreds of residences and some businesses. Inflow winds into the tornado also produced significant tree and some structural damage across the central and southeastern portions of Walterboro. At the Low Country Regional Airport, winds associated with the tornado or winds flowing into the tornado damaged or destroyed most hangers and nearly two dozen aircraft. The tornado then mainly snapped or uprooted trees while sporadically touching down between the airport to just northeast of Cottageville, South Carolina.

From NOAA NCEI's Storm Events Database, the narrative the local forecast office wrote for Storm Data.

8 minutes of warning. NWS CHS issued a tornado warning for this county at 10:38 UTC, 8 minutes before the tornado touched down, in force until 11:15 UTC.

The county was under a tornado watch, issued at 07:21 UTC and running to 12:58 UTC.

Every warning and watch covering the touchdown point that day, from the Iowa Environmental Mesonet's archive of National Weather Service products. Lead time is measured from the issue of the warning in force to the touchdown time in the database, both of which were recorded to the minute by different people.

The Storm Prediction Center had this point in a Enhanced Risk, with a 0.10 chance of a tornado within 25 miles, in the hatched area where significant tornadoes were expected. The outlook in force was issued at 05:50 UTC.

SPC's Day 1 convective outlook as it stood when the tornado began, read at the touchdown point. The same archive is on the radar archive.

The radiosonde launches on either side of the tornado, from the nearest station that was launching then, drawn and analyzed the way Storm Lab does: the same diagram, the same parcel and shear definitions SPC's mesoanalysis uses.

Walterboro (RBW), 9 km from the path, in the two hours either side.

From the Iowa Environmental Mesonet's archive of airport observations.

The Charleston,SC radar (KCLX), 40 km away, was scanning. The volume nearest the touchdown began at 10:49 UTC.

Open the radar archive at this moment, over the track

Reflectivity and velocity, decoded from the Level II archive in the browser. Volumes take a few seconds to open the first time.

Local storm reports within 60 km of the path, in the three hours either side.

From the Iowa Environmental Mesonet's archive of National Weather Service local storm reports.

The live radar over the trackEvery 2020 tornado in South CarolinaEvery tornado in South Carolina since 1950Warnings in force in South Carolina nowThe forecast where you are

67 more were confirmed in the United States that day.

All 68 of them

Ratings are the survey's, read off the damage rather than measured; the rating scale is above. Tornado counts rise through the record as reporting improved, so a year in the 1950s is not comparable with one today except for the strongest tornadoes, which were always noticed.

NOAA Storm Prediction Center tornado database, 1950-2025, the official record kept by NOAA's Storm Prediction Center.