EF1 tornado, Shelbina to Lakenan, Missouri, February 27, 2011

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

February 27, 2011

Touchdown

6:45 PM CST (00:45 UTC)

Lifted

6:46 PM CST (00:46 UTC)

On the ground

1 minutes

Path length

1.0 miles (1.7 km)

Path width

30 yards (27 m)

Deaths

0

Injuries

0

County

Shelby County

Touchdown point

39.667, -92.036

Lift-off point

39.675, -92.019

Record number

1102271845-01

A quasi-stationary frontal boundary was the main focusing mechanism for a round of significant severe weather over the forecast area. A strong shortwave moved along the boundary triggering widespread showers and thunderstorms. Numerous reports of large hail, damaging winds and 22 tornadoes occurred with this system.

The tornado initially touched down 1.5 miles south of Shelbina just west of Highway 15, damaging a small storage building and scattering debris across Highway 15. The tornado then continued to the east-northeast, severely damaging a large metal farm building. The debris from this building was blown downwind over half a mile. The maximum damage was rated EF1, with a maximum wind speed around 90 mph. Total length of this tornado was around a mile, with a maximum width of 20 to 30 yards.

As the tornado crossed from far north central Monroe County into southern Shelby County it struck a farmstead just north of County Line Road. At this location two small grain bins were destroyed, one of which was wrapped around a power pole a quarter of a mile to the east. A larger grain bin was partially shifted off its foundation, and suffered a partial collapse on its west side. A nearby windmill was also destroyed. The damage was rated EF0, with a maximum wind speed around 80 mph and a width of 20 yards. The total overall length of the tornado for both Monroe and Shelby counties was 2 miles.

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.

The county was under a severe thunderstorm watch, issued at 23:33 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. The outlook in force was issued at 20:01 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.

Kirksville (IRK), 65 km from the path, in the two hours either side.

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

The St Louis radar (KLSX), 158 km away, was scanning. The volume nearest the touchdown began at 00:46 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 2011 tornado in MissouriEvery tornado in Missouri since 1950Warnings in force in Missouri nowThe forecast where you are

19 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.