EF2 tornado, Mc Kinley to Oakdale, Illinois, March 8, 2009

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 8, 2009

Touchdown

11:46 AM CDT (16:46 UTC)

Lifted

11:51 AM CDT (16:51 UTC)

On the ground

5 minutes

Path length

4.3 miles (6.9 km)

Path width

200 yards (183 m)

Deaths

0

Injuries

0

County

Washington County

Touchdown point

38.250, -89.597

Lift-off point

38.267, -89.521

Record number

0903081046-01

A strong cold front moved through the region triggering showers and thunderstorms. Damaging winds, large hail and tornadoes were reported with the storms.

A tornado touched down 5.5 miles west southwest of Oakdale and travelled to the northeast. A house on County Highway 29 sustained moderate damage with 4 windows blown out, a wall was buckled in, and siding and shingles were blown off. At this location it also overturned and destroyed a camper and the back end of a machine shed was torn off. Further down the road, a silo and two sheds were blown down. The falling silo hit two cows, killing one of them. The tornado then snapped off 2 large double-poled wooden high tension towers at the base. Also, it destroyed several pole sheds with the debris scattered hundreds of yards and snapped off numerous trees. On another farmstead, a brand new garage was destroyed and the home sustained minimal roof and siding damage before the tornado lifted and dissipated about a mile west of Oakdale.

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

14 minutes of warning. NWS LSX issued a tornado warning for this county at 16:32 UTC, 14 minutes before the tornado touched down, in force until 17:15 UTC.

The county was under a tornado watch, issued at 14:48 UTC and running to 18:07 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 0.10 chance of a tornado within 25 miles. The outlook in force was issued at 16:26 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), 109 km away, was scanning. The volume nearest the touchdown began at 16:45 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 2009 tornado in IllinoisEvery tornado in Illinois since 1950Warnings in force in Illinois nowThe forecast where you are

25 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.