F2 tornado, Steffenville, Missouri, May 10, 2003

1. F040 to 72 mph

   Light damage. Surface peeled off some roofs, gutters and siding damaged, branches broken, shallow-rooted trees pushed over.

2. F173 to 112 mph

   Moderate damage. Roofs badly stripped, mobile homes overturned or badly damaged, exterior doors lost, windows broken.

3. F2113 to 157 mphthis tornado

   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. F3158 to 206 mph

   Severe damage. Whole stories of well-built houses destroyed, large buildings badly damaged, trains overturned, trees debarked, heavy cars lifted and thrown.

5. F4207 to 260 mph

   Devastating damage. Well-built houses leveled, structures with weak foundations moved some distance, cars thrown and large missiles generated.

6. F5261 to 318 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

F2

Date

May 10, 2003

Touchdown

6:08 PM CDT (23:08 UTC)

Path length

20.0 miles (32.2 km)

Path width

200 yards (183 m)

Deaths

0

Injuries

6

Property damage

$5.0 million

County

Lewis County

Touchdown point

39.930, -91.830

Lift-off point

40.150, -91.500

Record number

207

A tornado formed just north of the Marion Lewis County line and continued northeast for 20 miles, eventually causing major damage in the city of Canton. The tornado first formed southeast of Steffenville where it damaged a barn and other outbuildings. Six homes suffered varying degrees of roof damage as the tornado crossed Highway N south of Ewing. The tornado crossed Highway 6 southeast of Ewing and damaged an electric substation. From Highway CC north to Highway P, about 20 homes and farm buildings suffered varying degrees of roof, siding and window damage. Numerous large trees were either uprooted or snapped off near the ground as well. The tornado crossed Highway 61 just southeast of Canton where it blew two tractor trailers off the road. Two men suffered minor injuries. The tornado then entered Canton about 630 pm. Information from Emergency Management personnel and city officials in Canton revealed 75-100 structures damaged with at least 40 receiving major damage. At Culver-Stockton College on the southeast side of town, the field house was flattened and another two story building lost its roof. Several very large trees on the campus were uprooted or snapped off near the ground. Four mobile homes on the north side of town were destroyed with four others suffering major damage. There were only 4 minor injuries reported in Canton.

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

21 minutes of warning. NWS LSX issued a tornado warning for this county at 22:47 UTC, 21 minutes before the tornado touched down, in force until 23:30 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 High Risk, with a 0.25 chance of a tornado within 25 miles, in the hatched area where significant tornadoes were expected. The outlook in force was issued at 12:05 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.

Quincy (UIN), 42 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), 171 km away, was scanning. The volume nearest the touchdown began at 23:08 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.

The live radar over the trackEvery 2003 tornado in MissouriEvery tornado in Missouri since 1950Warnings in force in Missouri nowThe forecast where you are

50 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.