EF0 tornado, Bookwater to Table Rock, Nebraska, December 15, 2021

1. EF065 to 85 mphthis tornado

   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. 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

EF0

Date

December 15, 2021

Touchdown

4:06 PM CST (22:06 UTC)

Lifted

4:08 PM CST (22:08 UTC)

On the ground

2 minutes

Path length

2.2 miles (3.5 km)

Path width

20 yards (18 m)

Deaths

0

Injuries

0

County

Pawnee County

Touchdown point

40.020, -96.100

Lift-off point

40.030, -96.060

Record number

2112151606-01

8 damage points were recorded along this path by NWS OAX, in the Damage Assessment Toolkit the survey teams carry. The strongest indicator was rated EF1. The highest wind the damage implies is 110 mph.

• Roof of large out building peeled off. Wrap around porch detached from house. Couldn’t get to house due to downed power lines. Several wooden power poles snapped at bases
• Siding torn from Methodist church. Leaning wood over utility poles. Top of half pine tree snapped off. Convergent flow, doesn’t appear to be tornado
• Portion of center pivot turned over
• 40x60 metal outbuilding destroyed. Appears to wind entered one or more doors and lifted roof. Corner post not cemented. No apparent sill strapping. Large farm equipment remained in place. Some evidence of convergent flow. Radar appears to show descending RIJ.

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.

Brief swirl southwest of outbuilding destroyed. Debris strewn in narrow bath to the northeast.

A brief tornado destroyed half of a large outbuilding.

A brief tornado destroyed several outbuildings and removed a wrap-around porch from a house.

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

No tornado warning for this county appears in the archive as in force at the moment the tornado touched down. One was issued for the county at another hour that day.

The county was under a tornado watch, issued at 19:23 UTC and running to 23:19 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 0.02 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.

Falls City/Brenn (FNB), 42 km from the path, in the two hours either side.

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

The Topeka radar (KTWX), 115 km away, was scanning. The volume nearest the touchdown began at 22:05 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.