EF1 tornado, Plainfield Clow Arpt, Illinois, August 4, 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

August 4, 2008

Touchdown

7:45 PM CDT (00:45 UTC)

Lifted

7:46 PM CDT (00:46 UTC)

On the ground

1 minutes

Path length

1.1 miles (1.8 km)

Path width

50 yards (46 m)

Deaths

0

Injuries

0

Property damage

$500,000

County

Will County

Touchdown point

41.693, -88.153

Lift-off point

41.689, -88.132

Record number

0808041845-02

A powerful line of thunderstorms moved across northern Illinois during the evening hours of August 4th. Widespread and significant wind damage was reported along with several brief tornadoes on the leading edge of this line of storms. Close to 550,000 customers lost power during these thunderstorms. In the City of Chicago, more than 4,400 trees suffered some amount of damage, 161 light poles were damaged and 252 power lines were blown down.

A tornado developed about one half mile east of Plainfield Naperville Road and about one block south of Boughton Road. There was a narrow path of more intense damage in a subdivision where several homes had sections of roofing torn off, siding and soffits torn loose, trees snapped and limbs blown down. The most intense damage was on Sparrow Lane, Maroon Bell Lane and Silverado Street. The tornado was rated EF1 at this point. Here one house was likely a total loss due to structural damage to the roof, covered porch, garage and one wall. A garage was destroyed at another home. The tornado weakened to EF0 east of this area from Kings Road to Indian Chase Meadows. There was sporadic damage to trees and limbs and a few homes had damage to shingles, siding and soffits. A small section of roof was removed from a house just east of Indian Chase Meadows. At this point, the tornado appears to have dissipated, but strong straight line winds fanned out.

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. One was issued for the county at another hour that day.

The county was under a severe thunderstorm watch, issued at 00:21 UTC and running to 02:49 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 0.02 chance of a tornado within 25 miles. The outlook in force was issued at 22:44 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 Chicago radar (KLOT), 11 km away, was scanning. The volume nearest the touchdown began at 01:03 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 IllinoisEvery tornado in Illinois since 1950Warnings in force in Illinois nowThe forecast where you are

7 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.