EF2 tornado, Smithville to Lathrop, Missouri, March 6, 2017

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 mph

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

3. EF2111 to 135 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. 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

EF2

Date

March 6, 2017

Touchdown

7:24 PM CST (01:24 UTC)

Lifted

7:46 PM CST (01:46 UTC)

On the ground

22 minutes

Path length

19.6 miles (31.5 km)

Path width

1,000 yards (914 m)

Deaths

0

Injuries

0

Counties

Clay and Clinton counties

Touchdown point

39.428, -94.599

Lift-off point

39.558, -94.273

Record number

1703061924-01

41 damage points were recorded along this path by NWS EAX, in the Damage Assessment Toolkit the survey teams carry. The strongest indicator was rated EF2. The highest wind the damage implies is 132 mph.

• starting point of the tornado. perhaps 1/4 mile west of this location. no visible damage west though.
• northern edge of about 1/2 mile width.

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

On the evening of March 6, 2017 a line of severe thunderstorms formed, then moved into eastern Kansas and western and central Missouri. Ahead of and along this line of storms supercells formed and produced large hail, damaging winds, and several tornadoes. Officially there were 11 tornadoes recorded in the EAX portion of Missouri, with a 12th tornado recorded in Leawood, Kansas, on the Kansas side of the EAX CWA. The most notable of the tornadoes were the EF-2 and EF-3 tornadoes that impacted Smithville, Missouri and Oak Grove, Missouri respectively. According to news reports there were 12 injuries associated with the Oak Grove tornado, but despite the widespread significant damage there were no fatalities. As the line of storms moved eastward several embedded supercells and mesovortices produced several more tornadoes across northern and central Missouri. By the end of the event, officially there were four EF-1 tornadoes, one EF-2 tornado (Smithville, MO), one EF-3 (Oak Grove, MO), and five EF-0 tornadoes in Missouri. The Leawood Kansas tornado was rated EF-0 as well, rounding out the 12 confirmed tornadoes in the EAX CWA from that evening.

On the evening of March 6, a supercell ahead of a squall line produced a strong tornado that impacted the city of Smithville near Smithville Lake. The tornado formed just west of HWY 169 and did some minor damage to a neighborhood just east of HWY 169. More significant damage was done to a neighborhood along Route W, just east of HWY 169 before the tornado crossed Smithville Lake into Clinton County. At this neighborhood near the intersection of HWY 169 and Route W several houses were completely destroyed with roofs gone, but most external and interior walls still standing. There were also a couple residences that had compete failure of the structure as wind entered through garage doors and uplifted the entire house off the foundation. EF-2 rating was obtained mainly due to lack of structural failure of a majority of the residences. The house that was lifted off the foundation appeared to be a sliding house with winds entering in through a garage door. Surrounding residences had major damage, but not complete failure of structure. Despite the widespread damage from this tornado there were no injuries reported. This tornado crossed Route W and started across Smithville Lake, where it crossed into Clinton County.

This tornado is a continuation of the tornado that moved out of Clay County after impacting Smithville and Smithville Lake on the night of March 6. The tornado reached its strongest rating and its widest size as it crossed out of Clay County into Clinton County while it crossed Smithville Lake. Like in Clay County several residences were impacted in Clinton County by this large tornado that reached 1000 yards wide at its largest point. The worst of the damage occurred just east of Smithville lake where numerous structures were completely destroyed, but like on the west side of the lake the worst of the damage seemed to occur where garage doors became a point of entry for 100+ mph winds and lifted the entire structure off of its foundation. The tornado continued across the rural portions of Clinton County, remaining at least EF-2 until it approached Lathrop, where it became smaller and didn't create as much damage. A few structures on the south end of Lathrop were damaged. The last damage point appeared to be just west of Interstate 35, where a few metal outbuildings had some metal peeled off, but no more damage was located east of I-35. The tornado dissipated between Lathrop and Interstate 35.

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

25 minutes of warning. NWS EAX issued a tornado warning for this county at 00:59 UTC, 25 minutes before the tornado touched down, in force until 01:30 UTC.

The county was under a tornado watch, issued at 20:52 UTC and running to 03:03 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 0.10 chance of a tornado within 25 miles, in the hatched area where significant tornadoes were expected. The outlook in force was issued at 00:54 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 Pleasant Hill radar (KEAX), 77 km away, was scanning. The volume nearest the touchdown began at 01:24 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 2017 tornado in MissouriEvery tornado in Missouri since 1950Warnings in force in Missouri nowThe forecast where you are

53 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.