EF0 tornado, Lehigh, Illinois, June 20, 2011

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

June 20, 2011

Touchdown

6:14 AM CDT (11:14 UTC)

Lifted

6:17 AM CDT (11:17 UTC)

On the ground

3 minutes

Path length

2.4 miles (3.9 km)

Path width

100 yards (91 m)

Deaths

0

Injuries

0

Property damage

$100,000

County

Kankakee County

Touchdown point

41.118, -88.026

Lift-off point

41.147, -88.000

Record number

1106200514-01

Strong to severe thunderstorms moved across parts of central Illinois during the morning hours of June 20th.

The survey team reported a housing residence along Route 17 that had a shed completely destroyed, with the walls collapsed and the roof blown approximately 25 feet away. There was extensive hardwood tree damage for most of the damage path. Most of the trees damaged were either uprooted or snapped off at the base. These were large, mostly healthy trees. There were several trees where the break was a third to half of the way up the tree trunk. One of the housing structures along 7000W had a glass window blown out. An additional building had damage in the siding from a branch piercing the outer wall. Along 2000N, there were several occurrences of damage to man-made objects at several homesteads. The door on a large tin barn was blown into the structure and several panels of the siding collapsed. On the same property, a wooden corn shed was completely destroyed, and a house sustained shingle damage. A metal siding fence also blew down on the property line, as well as a chain link fence. Another property on 2000N incurred heavy structural damage due to fallen trees. Along the damage path, there were convergent wind patterns in several corn and wheat fields. In addition, the fallen trees laid in a convergent pattern. Many branches were speared into the ground in a convergent pattern, as well. The nature of this damage was consistent with an EF1 tornado with winds of 100 to 110 mph.

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

No tornado warning for this county appears in the archive as in force at the moment the tornado touched down.

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 0.02 chance of a tornado within 25 miles. The outlook in force was issued at 06:00 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.

Kankakee (IKK), 16 km from the path, in the two hours either side.

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

The Chicago radar (KLOT), 53 km away, was scanning. The volume nearest the touchdown began at 11:12 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 2011 tornado in IllinoisEvery tornado in Illinois since 1950Warnings in force in Illinois nowThe forecast where you are

37 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.