EF1 tornado, Richwoods to Otto, Missouri, April 30, 2010

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

April 30, 2010

Touchdown

8:08 PM CDT (01:08 UTC)

Lifted

8:40 PM CDT (01:40 UTC)

On the ground

32 minutes

Path length

18.3 miles (29.5 km)

Path width

581 yards (531 m)

Deaths

0

Injuries

0

Counties

Jefferson and Washington counties

Touchdown point

38.192, -90.785

Lift-off point

38.355, -90.519

Record number

1004301908-01

Storms developed ahead of a strong cold front during the afternoon and evening hours. Numerous reports of severe weather were received including large hail, damaging winds and tornadoes.

A tornado touched down in eastern Washington county about 4 miles northwest of Fletcher and travelled to the northeast. It blew down several large trees before crossing into Jefferson county, about 3 miles northwest of Fletcher.

The tornado crossed into Jefferson county about 3 miles northwest of Fletcher. The tornado travelled northeast crossing just north of Morse Mill on State Highway B. The tornado continued northeast passing through Lake Tishomingo, finally lifting 1.5 miles southwest of Otto. The tornado snapped and uprooted numerous trees and downed numerous tree limbs along the entire path. There were several areas of more substantial damage. On Brook Hollow Lane, 3 miles north northwest of Fletcher, a home was damaged with part of the roof removed and a wall of the garage destroyed. Also, on Brook Hollow Lane, a manufactured home sustained roof, siding and window damage. Another area of damage was along Highway B just north of the Big River. An outbuilding of the Morse Mill Baptist Church had the overhead doors caved in, which caused the roof to be removed and parts of the exterior walls to fail. The last area of significant damage was at Lake Tishomingo, especially along the north shore. Several of the homes suffered damage to the roofs and porches. Also, a number of homes were damaged when trees fell on them. No injuries were reported.

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

28 minutes of warning. NWS LSX issued a tornado warning for this county at 00:40 UTC, 28 minutes before the tornado touched down, in force until 01:30 UTC.

The county was under a tornado watch, issued at 19:40 UTC and running to 02:03 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 Moderate Risk, with a 0.15 chance of a tornado within 25 miles, in the hatched area where significant tornadoes were expected. The outlook in force was issued at 00:58 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.

The St Louis radar (KLSX), 47 km away, was scanning. The volume nearest the touchdown began at 01:06 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 2010 tornado in MissouriEvery tornado in Missouri since 1950Warnings in force in Missouri nowThe forecast where you are

24 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.