EF1 tornado, Norman to Stella, Oklahoma, May 21, 2019

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 21, 2019

Touchdown

4:22 AM CDT (09:22 UTC)

Lifted

4:24 AM CDT (09:24 UTC)

On the ground

2 minutes

Path length

1.4 miles (2.3 km)

Path width

30 yards (27 m)

Deaths

0

Injuries

0

County

Cleveland County

Touchdown point

35.358, -97.250

Lift-off point

35.356, -97.226

Record number

1905210322-01

54 damage points were recorded along this path by NWS OUN, in the Damage Assessment Toolkit the survey teams carry. The strongest indicator was rated EF2. The highest wind the damage implies is 127 mph.

• First indication of wind damage as radar vortex gens up.
• Numerous snapped and twisted trees, up to 8” diameter.
• Large tree snapped. 12” diameter limbs.
• Numerous large trees with snapped and twisted limbs 3-12” diameter in narrow swath. Note, not using the trunks snapped DOD, as I can’t get wind estimate under EF1. This is clearly EF0. I may correct this later.

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

An extremely unstable environment led to widespread severe weather across Texas and Oklahoma on the 20th into the morning of the 21st.

A tornado with a Quasi-Linear Convective system developed near E Alameda Street between 48th Avenue NE and 60th Avenue NE. It moved north-northeast to just east of 60th Avenue NE and Rock Creek Road, then turned north and then northwest dissipating about one-half mile northwest of 60th Avenue NE and Tecumseh Road. A number of trees were damaged along the path.

A QLCS tornado developed just west of the intersection of 84th Avenue NE and Franklin Road and moved about one-quarter mile northeast damaging trees and causing roof damage to a barn.

A QLCS tornado developed southwest of SE 104th Street and Indian Meridian Road in far southeast Oklahoma City and moved just south of due east dissipating after crossing Triple XXX Road. One outbuilding was heavily damaged near Triple XXX Road and a number of trees were damaged along the path.

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

14 minutes of warning. NWS OUN issued a tornado warning for this county at 09:08 UTC, 14 minutes before the tornado touched down, in force until 09:22 UTC.

The county was under a tornado watch, issued at 03:19 UTC and running to 09:46 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 Marginal Risk. The outlook in force was issued at 05:40 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), 4 km away, was scanning. The volume nearest the touchdown began at 09:18 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 2019 tornado in OklahomaEvery tornado in Oklahoma since 1950Warnings in force in Oklahoma nowThe forecast where you are

30 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.