F1 tornado, Calhoun to Green Ridge, Missouri, March 12, 2006

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 mphthis tornado

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

3. F2113 to 157 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. 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

F1

Date

March 12, 2006

Touchdown

3:50 PM CST (21:50 UTC)

Path length

13.0 miles (20.9 km)

Path width

150 yards (137 m)

Deaths

0

Injuries

0

Property damage

$100,000

Counties

Henry, Benton and Pettis counties

Touchdown point

38.480, -93.600

Lift-off point

38.550, -93.350

Record number

95

Tornado touched down in rural areas of Henry county...2 miles east northeast of Calhoun at 1550 CST. The tornado traveled northeast and crossed over into Benton county at 1552 CST.

This tornado is an extension of the Henry County tornado that eventually tracked into Pettis County following its track through far northwest Benton County. Damage to a few homes and barns along with trees and power poles occurred.

Tornado crossed into Pettis county from Benton county at 1557 CST. Tornado was over rural areas with no significant damage noted. The tornado dissipated at 1605 CST 1 mile west of Manila.

F2 tornado touched down 6.5 miles east of Green Ridge at 1612 CST and moved northeast. The tornado caused the death of one woman...when the trailer she was fleeing was blown on top of her. Another 6 people were injured as well. Numerous homes suffered varying degrees of damage. The tornado lifted one mile southwest of Smithton at 1625 CST.

The deaths

1 direct deaths are recorded for this tornado, each with what Storm Data knows of it.

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

15 minutes of warning. NWS EAX issued a tornado warning for this county at 21:35 UTC, 15 minutes before the tornado touched down, in force until 22:15 UTC.

The county was under a tornado watch, issued at 17:52 UTC and running to 02:42 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 0.30 chance of a tornado within 25 miles, in the hatched area where significant tornadoes were expected. The outlook in force was issued at 20:04 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.

Whiteman Afb (SZL), 25 km from the path, in the two hours either side.

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

The Pleasant Hill radar (KEAX), 76 km away, was scanning. The volume nearest the touchdown began at 21:50 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 2006 tornado in MissouriEvery tornado in Missouri since 1950Warnings in force in Missouri nowThe forecast where you are

54 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.