EF1 tornado, Howells, Nebraska, December 15, 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

December 15, 2021

Touchdown

3:27 PM CST (21:27 UTC)

Lifted

3:28 PM CST (21:28 UTC)

On the ground

1 minutes

Path length

1.5 miles (2.4 km)

Path width

30 yards (27 m)

Deaths

0

Injuries

0

County

Colfax County

Touchdown point

41.720, -97.000

Lift-off point

41.740, -97.000

Record number

2112151527-01

19 damage points were recorded along this path by NWS OAX, in the Damage Assessment Toolkit the survey teams carry. The strongest indicator was rated EF2. The highest wind the damage implies is 120 mph.

• Owner had video. Debris scattered northwest of maple creek (0.5 miles to the north)
• Multiple well constructed large farm buildings destroyed.
• Damage to large barn roof, trees snapped, siding removed
• 5 poles were broken just down the road. Was bolted down but open to south and older building.

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

A low pressure system brought strong (both thunderstorm, and non-thunderstorm) winds, tornadoes, dust, snow, and record temperatures into eastern Nebraska and western Iowa. The event was determined to be a derecho meeting the criteria of wind damage extending more than 250 miles, including wind gusts of at least 58 mph and numerous gusts of at least 75 mph.

An intermittent tornado tracked from south to north through Howells. The initial damage point was roof damage to a home on the south side of town along with moderate tree damage. The tornado then skipped several blocks before removing a portion of the building attached to the feed and seed. Nearby security cameras provided video evidence of the brief tornadic circulation on the north side of town. The tornado remained intermittent as it travelled into an open field to the northeast, depositing debris in the field.

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

37 minutes of warning. NWS OAX issued a tornado warning for this county at 20:50 UTC, 37 minutes before the tornado touched down, in force until 21:30 UTC.

The county was under a tornado watch, issued at 19:23 UTC and running to 22:18 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 19:28 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.

Columbus Municipal (OLU), 42 km from the path, in the two hours either side.

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

The Omaha radar (KOAX), 70 km away, was scanning. The volume nearest the touchdown began at 21:27 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 NebraskaEvery tornado in Nebraska since 1950Warnings in force in Nebraska nowThe forecast where you are

124 more were confirmed in the United States that day.

All 125 of them

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.