EF1 tornado, Alger to Ada, Ohio, December 11, 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 11, 2021

Touchdown

3:06 AM EST (08:06 UTC)

Lifted

3:10 AM EST (08:10 UTC)

On the ground

4 minutes

Path length

1.6 miles (2.6 km)

Path width

150 yards (137 m)

Deaths

0

Injuries

0

Property damage

$300,000

County

Hardin County

Touchdown point

40.730, -83.826

Lift-off point

40.740, -83.799

Record number

2112110206-01

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

• Small camper rolled and destroyed

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

Showers and thunderstorms developed during the early morning hours ahead of an approaching cold front.

The first sign of tornadic damage was observed at a residence just southwest of the intersection of State Routes 309 and 235, where part of the roof was lifted off of a barn and multiple softwood trees were snapped and blown in multiple directions.||The tornado then strengthened as it moved northeast, causing more substantial damage at a business and a two story residence, located on opposite sides of State Route 309, near the intersection with State Route 235. At the business, two outbuildings were completely destroyed and part of the roof of another building was lifted off, with debris splatter noted on multiple sides of this building. A metal sign was also damaged and a tractor trailer was overturned on its side.||At the two story home, the roof was completely lifted off, with parts of the roof thrown in multiple directions. Several windows were broken, most likely due to metal debris from the business across the road. Two outbuildings were completely destroyed. Debris from these outbuildings and debris from the home were blown at least 0.7 miles into the field to the northeast. Multiple trees also sustained significant damage. The tornado was strongest in this area, with maximum winds of up to 110 mph.||The tornado was likely still on the ground in the field to the northeast of State Route 235, however it showed signs of weakening as it crossed Township Road 55. On Township Road 55, shingles were removed from one home, while one outbuilding had partial roof uplift and another outbuilding was moved off cinder blocks. A few trees along a grove behind the home were also snapped.||Additional minor roof damage was observed on Township Road 64. This appears to be the end of the tornado as no further damage was noted to the northeast.

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.

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 General Thunderstorms Risk. The outlook in force was issued at 05:48 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 Cincinnati radar (KILN), 146 km away, was scanning. The volume nearest the touchdown began at 08:03 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 OhioEvery tornado in Ohio since 1950Warnings in force in Ohio nowThe forecast where you are

37 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.