F2 tornado, Midway to Hallsville, Missouri, April 8, 1999

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

April 8, 1999

Touchdown

6:05 PM CDT (23:05 UTC)

Path length

10.0 miles (16.1 km)

Path width

120 yards (110 m)

Deaths

0

Injuries

0

County

Boone County

Touchdown point

39.050, -92.350

Lift-off point

39.120, -92.170

Record number

339

A tornado first formed near Midway and created a 4 mile damage path as it moved northeast across Boone County. Damage first occurred along Locust Grove Road where 1 barn and 2 equipment buildings were destroyed and 3 homes suffered roof and siding damage. Numerous trees were blown down or snapped in two in this area. When the tornado crossed O.B. Brown Road, a mobile home was destroyed as were 7 outbuildings. One home completely lost its roof while another lost half of its roof. Witnessed described the tornado as a swirling mass of rain and debris.

The supercell that spawned the tornado near Midway created another tornado that first caused damage near Hinton. A couple of farm equipment buildings and a garage were destroyed. Near Hallsville, one home lost its roof and an equipment building was destroyed. 3 grain bins were destroyed with one landing about 3/4 mile from its original location. To the southeast of Hallsville 3 homes suffered roof damage, 1 barn, 2 equipment buildings and a grain bin were destroyed.

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

11 minutes of warning. NWS LSX issued a tornado warning for this county at 22:54 UTC, 11 minutes before the tornado touched down, in force until 23:45 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. The outlook in force was issued at 19:58 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.

Columbia (COU), 30 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), 143 km away, was scanning. The volume nearest the touchdown began at 23:03 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.

The live radar over the trackEvery 1999 tornado in MissouriEvery tornado in Missouri since 1950Warnings in force in Missouri nowThe forecast where you are

46 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.