EF1 tornado, Woodstock, Illinois, June 19, 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 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

June 19, 2009

Touchdown

7:10 PM CDT (00:10 UTC)

Lifted

7:12 PM CDT (00:12 UTC)

On the ground

2 minutes

Path length

0.7 miles (1.2 km)

Path width

75 yards (69 m)

Deaths

0

Injuries

0

Property damage

$75,000

County

McHenry County

Touchdown point

42.295, -88.441

Lift-off point

42.300, -88.428

Record number

0906191810-01

Severe thunderstorms moved across northern Illinois during the evening of June 19th producing widespread wind damage and some flash flooding. The City of Chicago reported almost 1,000 tree emergencies which includes damage to tree limbs, partial trees or entire trees.

A tornado touched down near Highway 14 and Davis Road. At this location, several pine trees had large branches sheared and topped off with two of the trees partially uprooted. At this point the tornado was rated EF0 with winds estimated near 85 mph and a path width of 20 yards. The tornado continued northeast, crossing Highway 14, into a neighborhood where it increased in intensity and produced damage to structures and trees. Damage in the area was to a garage adjacent to a main house. This well built and fairly new garage was lifted and turned off of its foundation, which was securely bolted to a concrete finish. Damage at this location was rated EF1 with winds estimated near 100 mph and a path width of 75 yards. The tornado proceeded to move northeast through the neighborhood where it uprooted four old but healthy soft and hard wood trees. Just to the northeast of this neighborhood is a commercial district where the tornado produced damage to two buildings. Damage occurred to the roof of one building with the other building sustaining damage to one of its exterior walls. The wall was partially collasped but it was an older structure. EF1 damage was produced at this point with winds estimated near 100 mph and a path width of 30 yards. The tornado weakened as it moved northeast, producing damage to trees near and along Lake Road. The tornado appeared to have lifted with no other damage evident beyond this point.

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 19:26 UTC and running to 00:44 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 19:57 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 Milwaukee radar (KMKX), 75 km away, was scanning. The volume nearest the touchdown began at 00:12 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 2009 tornado in IllinoisEvery tornado in Illinois since 1950Warnings in force in Illinois nowThe forecast where you are

6 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.