EF4 Etna–Centerpoint tornado, Arkansas, May 24, 2011

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 mph

   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 mphthis tornado

   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

EF4

Date

May 24, 2011

Touchdown

11:53 PM CDT (04:53 UTC)

Lifted

12:50 AM CDT (05:50 UTC)

On the ground

57 minutes

Path length

45.7 miles (73.5 km)

Path width

2,200 yards (2012 m)

Deaths

4

Injuries

27

Property damage

$9.1 million

Counties

Logan and Franklin counties

Touchdown point

35.278, -93.951

Lift-off point

35.691, -93.320

Record number

1105242253-01

16 damage points were recorded along this path by NWS TSA, in the Damage Assessment Toolkit the survey teams carry. The strongest indicator was rated EF4. The highest wind the damage implies is 170 mph.

• Sill plate on this home was bolted to the foundation (i.e. exceeded standard construction practices).
• mobile home frame found in large debris field mangled and twisted
• Sill plate of this house was bolted into the foundation (i.e. exceeded standard construction practices).
• 10 large (100 foot tall) metal poles bent near the ground

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

Severe thunderstorms developed along a dry line over central Oklahoma during the afternoon hours. Very unstable air and strong wind shear east of the dry line supported supercell thunderstorm structures, which persisted as the storms moved into northwestern Arkansas late in the evening. These severe storms produced tornadoes, large hail, and damaging downburst wind across portions of northwestern Arkansas. One of the tornadoes was especially intense, resulting in considerable damage to several towns as well as three fatalities in Franklin County.

This is the third of six segments of this tornado. The tornado snapped or uprooted a number of large trees as it moved back into Franklin County from Logan County. The damage path widened considerably to about 3/4 of a mile as the tornado moved north of Highway 398 and approached Etna. In and near Etna, the tornado destroyed a number of permanent homes, destroyed mobile homes, destroyed a metal building, destroyed a number of outbuildings, snapped numerous power poles, and snapped or uprooted many large trees. One of the three tornado-related fatalities in Franklin County occurred when a double-wide mobile home was destroyed in Etna. At least six serious injuries occurred in this area and several of those were critical.||Several well-built, wood-framed permanent homes were destroyed in Etna with only a small amount of debris remaining on the foundation. Trees were debarked in this area and the ground was scoured by debris. A well-built, two-story, steel-framed home northeast of Etna on Highway 309 was also destroyed with only a few interior walls remaining on the first floor. Two people survived in the kitchen pantry as the home was destroyed around them. Maximum estimated wind speed in this segment of the tornado based on this damage was about 170 mph.||The tornado continued into Logan County, Arkansas, at 1.25 miles wide.

This is the fifth of six segments of this tornado. The tornado crossed the Arkansas River, moving back into Franklin County from Logan County. The tornado crossed Carbon Plant Road and W Creek Road, destroying a mobile home and killing another person. It continued northeast across the town of Denning where it destroyed numerous permanent homes and mobile homes. At least 10 injuries occurred in Denning as the mile-wide tornado moved through the town. Several of these injuries were serious or critical and one of the victims died from her injuries on June 14th. She was in one of the many mobile homes that were destroyed in town. Ten 100-foot metal power poles were bent over at the ground by the tornado and many other power poles were snapped throughout the Denning area. Many large trees were also snapped or uprooted. Maximum estimated wind speed in this segment of the tornado based on this damage was about 145 mph.||The tornado moved northeast from Denning and crossed Highway 64, severely damaging the roof of a permanent home and snapping or uprooting numerous trees. The tornado continued into Johnson County, Arkansas.

The deaths

3 direct deaths are recorded for this tornado, each with what Storm Data knows of it.

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

26 minutes of warning. NWS TSA issued a tornado warning for this county at 04:27 UTC, 26 minutes before the tornado touched down, in force until 05:00 UTC.

The county was under a tornado watch, issued at 01:10 UTC and running to 05:54 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 Moderate Risk, with a 0.15 chance of a tornado within 25 miles, in the hatched area where significant tornadoes were expected. The outlook in force was issued at 01:05 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.

The Western Arkansas radar (KSRX), 69 km away, was scanning. The volume nearest the touchdown began at 04:52 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 2011 tornado in ArkansasEvery tornado in Arkansas since 1950Warnings in force in Arkansas nowThe forecast where you are

47 more were confirmed in the United States that day.

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.