EF1 tornado, Johnson, Oklahoma, April 19, 2023

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 19, 2023

Touchdown

10:39 PM CDT (03:39 UTC)

Lifted

10:40 PM CDT (03:40 UTC)

On the ground

1 minutes

Path length

0.8 miles (1.3 km)

Path width

50 yards (46 m)

Deaths

0

Injuries

0

County

Pottawatomie County

Touchdown point

35.428, -96.792

Lift-off point

35.419, -96.791

Record number

2304192139-01

304 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 135 mph.

• car flipped on power lines
• Went well below expected wind based on immediate surroundings.
• original entry was small barn; RS
• Semi truck blown over into light pole

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

Broad troughing was present aloft across the Western US during the afternoon/evening of the 19th. An area of surface low-pressure slowly deepened and moved towards north-central Kansas, with dryline extending from central Kansas through western-north Texas by the late afternoon hours. A well-timed lead upper wave, combined with broken insolation, led to the development of a few supercell thunderstorms across central Oklahoma. Multiple instances of large to very large (>2 inches) hail, along with 18 tornadoes, occurred across central Oklahoma.

The eighteenth and final tornado of this outbreak developed northeast of Johnson, or from 1 mile northwest to 1 mile west of Garden Grove. This tornado moved south near and just west of Econtuchka Road dissipating just southwest of the intersection of Econtuchka Road and Wolverine Road. A home received roof damage, an outbuilding was destroyed and trees were damaged along the path.

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

2 minutes of warning. NWS OUN issued a tornado warning for this county at 03:37 UTC, 2 minutes before the tornado touched down, in force until 03:53 UTC.

The county was under a tornado watch, issued at 21:49 UTC and running to 04:00 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 Slight Risk, with a 0.05 chance of a tornado within 25 miles. The outlook in force was issued at 00:48 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), 45 km away, was scanning. The volume nearest the touchdown began at 03:40 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 2023 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.