EF3 tornado, Bennington to Unger, Oklahoma, May 9, 2016

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 mphthis tornado

   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

EF3

Date

May 9, 2016

Touchdown

6:22 PM CDT (23:22 UTC)

Lifted

6:42 PM CDT (23:42 UTC)

On the ground

20 minutes

Path length

13.8 miles (22.2 km)

Path width

3,100 yards (2835 m)

Deaths

0

Injuries

2

Property damage

$3.0 million

Counties

Bryan and Choctaw counties

Touchdown point

33.965, -95.991

Lift-off point

34.005, -95.759

Record number

1605091722-01

106 damage points were recorded along this path by NWS TSA, in the Damage Assessment Toolkit the survey teams carry. The strongest indicator was rated EF3. The highest wind the damage implies is 152 mph.

• numerous trees uprooted and snapped
• trees blocking road to south; heavy tree damage; trees blown down in various directions
• 2 large metal trusses down
• metal frame bent; much of walls and roof blown off

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

With the help of an upper low, storms fired along the dryline in central Oklahoma on the 9th, with some of them becoming severe.

Severe thunderstorms developed along and ahead of a dry line across central Oklahoma during the afternoon of May 9th. The storms moved across eastern Oklahoma during the evening hours. Prior to the storms moving into the area, the atmosphere ahead of the dry line in eastern Oklahoma had become very unstable. This instability, combined with very strong wind shear associated with a strong trough of low pressure that moved into the Southern Plains from the Southern Rockies, resulted in the development of supercell thunderstorms. One of these supercells produced multiple tornadoes as it tracked along and near an outflow boundary from morning thunderstorms, which had settled across southeastern Oklahoma by the afternoon. One of the tornadoes was long-lived and damaging. In addition to the tornadoes in southeastern Oklahoma, the severe thunderstorms produced hail up to golfball size and damaging wind gusts across other portions of eastern Oklahoma.

A tornado developed southeast of Bennington, and quickly became very large as it moved east-northeast. Widespread destruction of trees was observed across eastern Bryan County. The tornado moved into Choctaw County southwest of Boswell. See the eastern Oklahoma Storm Data entry from NWS Tulsa for information about this tornado in Choctaw County.

This is the second segment of a two segment tornado that began at 624 pm CDT in Bryan County, Oklahoma. The tornado strengthened and widened rapidly after developing southeast of Bennington. It was about 2500 yards wide and was producing EF-2 damage to trees by the time it reached the Choctaw County border at around 627 pm CDT. ||In Choctaw County, the tornado continued to widen as it moved northeast, producing a damage path of about 1.8 miles across, to the southwest of Boswell. The tornado made a turn to the east at the N4000 Road and maintained an eastward movement until dissipating before reaching the N4090 Road. The tornado destroyed at least three mobile homes. Two injuries occurred in one of the mobile homes, one of which was a critical injury. Numerous homes were damaged by this tornado, with the worst damage including major loss of the roof structure and collapse of a few exterior walls. Numerous outbuildings were also destroyed. A metal, high-voltage transmission tower/truss was destroyed, and numerous power poles were snapped. Many trees were snapped or uprooted in the path. Trees in several areas were reduced to shortened trunks with short stumps where large limbs previously existed. Based on this damage, maximum estimated wind in this segment of the tornado was 140 to 150 mph.

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

25 minutes of warning. NWS OUN issued a tornado warning for this county at 22:57 UTC, 25 minutes before the tornado touched down, in force until 23:30 UTC.

The county was under a tornado watch, issued at 19:36 UTC and running to 00:20 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. The outlook in force was issued at 20:00 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 Norman radar (KTLX), 197 km away, was scanning. The volume nearest the touchdown began at 23:24 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 2016 tornado in OklahomaEvery tornado in Oklahoma since 1950Warnings in force in Oklahoma nowThe forecast where you are

27 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.