EF1 tornado, Hanna to Raiford, Oklahoma, May 27, 2021

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

May 27, 2021

Touchdown

7:13 PM CDT (00:13 UTC)

Lifted

7:17 PM CDT (00:17 UTC)

On the ground

4 minutes

Path length

3.0 miles (4.8 km)

Path width

500 yards (457 m)

Deaths

0

Injuries

0

Property damage

$25,000

County

McIntosh County

Touchdown point

35.265, -95.869

Lift-off point

35.254, -95.818

Record number

2105271813-01

12 damage points were recorded along this path by NWS TSA, in the Damage Assessment Toolkit the survey teams carry. The strongest indicator was rated EF1. The highest wind the damage implies is 93 mph.

• Small tree snapped westward

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

Severe thunderstorms developed across eastern Oklahoma during the afternoon of the 27th, near an outflow boundary from previous storms, and ahead of a cold front. These storms eventually organized into a line and moved through southeastern Oklahoma during the evening. A tornado, large hail up to baseball size, and damaging wind occurred as the storms moved through the area. Some of the thunderstorms moved repeatedly over the same areas, and produced very heavy rainfall rates, which resulted in flash flooding.

This tornado developed north of Highway 9 and west of Red Hill Road, where large tree limbs were snapped. The tornado moved east-southeast damaging a barn, uprooting a tree, and snapping large tree limbs as it moved along Highway 9. A home was damaged, several trees were uprooted, and a small tree was snapped as the tornado crossed the 4030 Road. It dissipated south of Highway 9 and east of the 4030 Road over open country. Based on this damage, maximum estimated wind in the tornado was 90 to 95 mph.

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

6 minutes of warning. NWS TSA issued a tornado warning for this county at 00:07 UTC, 6 minutes before the tornado touched down, in force until 00:35 UTC.

The county was under a tornado watch, issued at 16:58 UTC and running to 02:00 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 0.05 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.

Mc Alester Regional (MLC), 42 km from the path, in the two hours either side.

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

The Tulsa radar (KINX), 105 km away, was scanning. The volume nearest the touchdown began at 00:13 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 2021 tornado in OklahomaEvery tornado in Oklahoma since 1950Warnings in force in Oklahoma nowThe forecast where you are

5 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.