EF1 tornado, Van Petten to Henkel, Illinois, June 22, 2015

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 22, 2015

Touchdown

7:28 PM CDT (00:28 UTC)

Lifted

7:40 PM CDT (00:40 UTC)

On the ground

12 minutes

Path length

7.4 miles (12.0 km)

Path width

50 yards (46 m)

Deaths

0

Injuries

0

County

Lee County

Touchdown point

41.744, -89.592

Lift-off point

41.697, -89.462

Record number

1506221828-01

44 damage points were recorded along this path by NWS DVN and NWS LOT, in the Damage Assessment Toolkit the survey teams carry. The strongest indicator was rated EF2. The highest wind the damage implies is 130 mph.

• apparent tornado beginning
• From ABC7 aerial footage. Tree uprooted to the S or SSW.
• From ABC7 aerial footage. Large group of evergreen trees with tops snapped off or most large branches broken. A few trees uprooted in vicinity. Trees no longer exist on aerial imagery.
• From ABC7 aerial footage. Large tree uprooted to the south.

Survey points are preliminary and are the raw material the published rating was built from. Source: NWS Damage Assessment Toolkit.

During the evening of June 22, twelve tornadoes occurred across northern Illinois, including ten in the WFO Chicago forecast area. Ten of the twelve were spawned from a single long-lived cyclic supercell, which tracked across Whiteside, Lee, LaSalle, Grundy, Will, and Kankakee Counties. The heaviest damage was in Coal City (Grundy County) and Braidwood (Will County) which was caused by an EF-3 tornado with maximum winds of 160 mph, and the Woodhaven Campground in Sublette (Lee County) caused by an EF-2 tornado with maximum winds of 130 mph. There were 14 injuries reported. There were no fatalities. The EF-3 Coal City to Braidwood tornado was the strongest tornado in Grundy County since an F3 tornado struck on July 17, 1972. The atmosphere was primed for severe weather, with very warm, humid conditions, low pressure moving north of the region, and a strong jet stream aloft. An outflow boundary from earlier storms during the late morning and early afternoon may have been key to where the long-lived tornado-producing storm tracked. In addition to tornado and wind damage, slow moving storms brought torrential rainfall of locally up to 3 to 5 inches to portions of Lee, Grundy, Will, and Kankakee counties, resulting in widespread flash flooding. This rain fell on top of soil already saturated from repeated heavy rains over the past few weeks.

This is a continuation of a tornado that began in Whiteside County (NWS Quad Cities). The tornado crossed the county line and did no additional damage. (Tornado 1 of 10).

The tornado touched down near Howland Road where hardwood trees were snapped. The tornado moved southeast just north of Harmon where additional trees were snapped. The tornado snapped trees as it cross Hoyle Road. The tornado lifted before reaching IL-26. Peak winds were estimated to be 105 mph. (Tornado 2 of 10).

Very significant tree damage occurred with many large trees snapped or uprooted in Woodhaven Lakes Camping Resort. At least one house was pushed off of its foundation. Several trees fell onto recreational vehicles and it was estimated that around 100 of the 300 homes in the area received some degree of damage. One person was taken to the hospital in serious condition, and six others were injured. Peak winds were estimated to be 130 mph. (Tornado 3 of 10).

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

25 minutes of warning. NWS LOT issued a tornado warning for this county at 00:03 UTC, 25 minutes before the tornado touched down, in force until 01:00 UTC.

The county was under a tornado watch, issued at 20:57 UTC and running to 02:16 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 Enhanced Risk, with a 0.10 chance of a tornado within 25 miles. The outlook in force was issued at 20:07 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 Quad Cities radar (KDVN), 88 km away, was scanning. The volume nearest the touchdown began at 00:27 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 2015 tornado in IllinoisEvery tornado in Illinois since 1950Warnings in force in Illinois nowThe forecast where you are

26 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.