EF1 tornado, Riverdale, Missouri, January 7, 2008

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

January 7, 2008

Touchdown

9:36 PM CST (03:36 UTC)

Lifted

9:37 PM CST (03:37 UTC)

On the ground

1 minutes

Path length

0.4 miles (0.6 km)

Path width

100 yards (91 m)

Deaths

0

Injuries

1

Property damage

$200,000

County

Christian County

Touchdown point

36.967, -93.304

Lift-off point

36.968, -93.298

Record number

0801072136-01

An unusual mid winter tornado outbreak occurred over southwest and central Missouri. 31 tornadoes struck the region within a 15 hour time frame on 7 January into early morning 8 January. Two tornadoes intensified to EF-3 status while five tornadoes caused EF-2 damage. All other tornadoes during this outbreak were surveyed and given EF-0 and EF-1 status. Multiple training supercells spawned most of these tornadoes that occurred along the Interstate 44 corridor. Toward the end of this episode, a broken squall line spawned numerous EF-0 and EF-1 tornadoes across the southern Missouri Ozarks.

A National Weather Service storm survey revealed that an EF-1 tornado tracked across a rural section of west central Christian County. This tornado damaged numerous homes while destroying two mobile homes. One injury resulted from this tornado as one women was hit by debris as the tornado destroyed her mobile home.

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

6 minutes of warning. NWS SGF issued a tornado warning for this county at 03:30 UTC, 6 minutes before the tornado touched down, in force until 04:30 UTC.

The county was under a tornado watch, issued at 01:49 UTC and running to 10:05 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 Slight 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 01:00 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 Springfield radar (KSGF), 31 km away, was scanning. The volume nearest the touchdown began at 03:35 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 2008 tornado in MissouriEvery tornado in Missouri since 1950Warnings in force in Missouri nowThe forecast where you are

33 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.