EF0 tornado, Carrollton, Illinois, August 31, 2012

1. EF065 to 85 mphthis tornado

   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 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

EF0

Date

August 31, 2012

Touchdown

3:27 PM CDT (20:27 UTC)

Lifted

3:30 PM CDT (20:30 UTC)

On the ground

3 minutes

Path length

1.4 miles (2.3 km)

Path width

60 yards (55 m)

Deaths

0

Injuries

0

County

Greene County

Touchdown point

39.282, -90.408

Lift-off point

39.303, -90.409

Record number

1208311427-01

With the remnant low of the Hurricane Isaac centered over southwestern Missouri, numerous showers and thunderstorms developed and rotated cyclonically around the remnant low. A few of the thunderstorms produced brief spinup tornadoes.

The tornado first touched down about 200 yards south of County Road 1150, about 80 yards west of U.S. Highway 67, damaging a four car garage. The roof of the garage was mostly removed from the structure with some small sections of the roof displaced a quarter of a mile to the north in an open field. The tornado travelled to the north over County Road 1150 and snapped some medium sized tree limbs. One power pole was snapped in this area. Also, a medium size storage unit was damaged with pieces of the storage unit displaced over 100 yards to the north. The tornado moved north nearly parallel to 6th Street where small and large tree limbs were snapped. Several witnesses including the local street department observed the tornado as it entered and moved through a residential area west of downtown Carrollton. One home near the southern part of the residential area sustained minor roof damage with shingles removed from the roof. The tornado crossed Illinois Route 108 just west of U.S. Highway 67 before lifting and dissipating. Mainly small to medium tree limbs were blown down as the tornado travelled north through this area. The path length of the tornado was approximately 1.44 miles and had a damage width which varied between 40 and 60 yards. The damage was rated EF0.

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

0 minutes of warning. NWS LSX issued a tornado warning for this county at 20:27 UTC, 0 minutes before the tornado touched down, in force until 21:15 UTC.

The county was under a tornado watch, issued at 18:58 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 Slight Risk, with a 0.05 chance of a tornado within 25 miles. 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.

St. Charles (SET), 40 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), 70 km away, was scanning. The volume nearest the touchdown began at 20:27 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 2012 tornado in IllinoisEvery tornado in Illinois since 1950Warnings in force in Illinois nowThe forecast where you are

5 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.