Unrated tornado, Aroya to Sorrento, Colorado, April 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 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 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. Unratedthis tornado

   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

Unrated

Date

April 27, 2021

Touchdown

4:08 PM MDT (22:08 UTC)

Lifted

4:18 PM MDT (22:18 UTC)

On the ground

10 minutes

Path length

2.0 miles (3.3 km)

Path width

100 yards (91 m)

Deaths

0

Injuries

0

County

Cheyenne County

Touchdown point

38.615, -103.162

Lift-off point

38.619, -103.125

Record number

2104271608-02

A frontal boundary slowly pushed north across eastern Colorado during the afternoon hours before shifting east into western Kansas and extreme southwest Nebraska during the evening hours. Storms formed along and north of the front and moved across eastern Colorado producing tornadoes, up to golf ball sized hail, and up to 60 mph wind gusts.

First of several tornadoes that occurred in quick succession. This was the larger initial one that was captured by storm chaser footage and reported by law enforcement.

This second tornado occurred simultaneously with a larger tornado (first tornado entered). This one was visually smaller according to storm chaser footage.

Chaser footage showed a smaller satellite tornado to the parent circulation. This tornado began, and was immediately followed by a much larger tornado. This is the third tornado produced by this storm in short succession.

This is the fourth tornado that occurred in rapid succession. This tornado, visually from storm chaser stream, was the largest tornado of the day. It continued across open country of southwestern Cheyenne County Colorado. A satellite tornado began shortly before this one, which was the third tornado of the day.

Tornadoes viewed on live chase stream. Based on photos/videos submitted, as well as radar imagery, believe this to be the fifth tornado produced by this storm.

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

2 minutes of warning. NWS GLD issued a tornado warning for this county at 22:06 UTC, 2 minutes before the tornado touched down, in force until 22:30 UTC.

The county was under a severe thunderstorm watch, issued at 17:47 UTC and running to 01:00 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 Marginal Risk. The outlook in force was issued at 19:49 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 Pueblo radar (KPUX), 92 km away, was scanning. The volume nearest the touchdown began at 22:10 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 ColoradoEvery tornado in Colorado since 1950Warnings in force in Colorado nowThe forecast where you are

13 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.