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.

Thunderstorm Wind in GRUNDY, ILLINOIS
From 22-JUN-15 20:30:00 to 22-JUN-15 20:30:00 (CST-6)
Location: LANGHAM
Magnitude: 50.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Public

Large tree limbs were blown down and a barn received minor damage near Dupont Road and Gonnam Road.

Flash Flood in WILL, ILLINOIS
From 22-JUN-15 21:50:00 to 23-JUN-15 04:00:00 (CST-6)
Location: RITCHIE
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Amateur Radio

Approximately six inches of flowing water was reported over Illinois Route 102 in Ritchie.

Strong Wind in WILL, ILLINOIS
From 22-JUN-15 15:05:00 to 22-JUN-15 15:50:00 (CST-6)
Magnitude: 43.00 MG
Property damage: 0.50K
Crop damage: 0.00K
Reported by: Official NWS Observations

A wind gust to 49 mph was measured at NWS Chicago, while a 48 mph gust was measured at Joliet Airport.  A twelve inch diameter tree was blown down near Route 59 and Caton Farm Road. Several four to ten inch tree limbs were blown down near Larkin and Theodore.  A six to eight inch limb was blown down on the west side of Joliet near County Line Road.  An eleven inch diameter limb was blown down in Lockport near State Street and 17th.  A large tree was blown down onto eastbound I-80 east of Larkin.

Tornado in WILL, ILLINOIS
From 22-JUN-15 20:58:00 to 22-JUN-15 21:12:00 (CST-6)
Location: BRAIDWOOD
Tornado F-scale: EF2
Property damage: 250.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

This is a continuation of a tornado that begin in Grundy County.  The tornado crossed into Will County near E Reed Road. The tornado crossed part of the property of the Braidwood Nuclear Generating Station producing tree damage.  Wooden power poles were broken along Route 53, and again along Zilm Road.  A garage was nearly completely destroyed along Ohlhues Road.    (Tornado 8b of 10).

Tornado in GRUNDY, ILLINOIS
From 22-JUN-15 20:43:00 to 22-JUN-15 20:46:00 (CST-6)
Location: GORMAN
Tornado F-scale: EF1
Property damage: 50.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

The tornado blew off a portion of the roof of a house and snapped a large tree.  Peak winds were estimated at 95 mph. (Tornado 7 of 10).

Tornado in LEE, ILLINOIS
From 22-JUN-15 18:53:00 to 22-JUN-15 19:11:00 (CST-6)
Location: MAYTOWN
Tornado F-scale: EF2
Property damage: 1.00M
Crop damage: 0.00K
Reported by: NWS Storm Survey

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).

Thunderstorm Wind in LEE, ILLINOIS
From 22-JUN-15 19:19:00 to 22-JUN-15 19:19:00 (CST-6)
Location: SUBLETTE ARPT
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A one foot diameter tree was snapped at the base on Route 251 at the county line.

Tornado in KANKAKEE, ILLINOIS
From 22-JUN-15 21:08:00 to 22-JUN-15 21:12:00 (CST-6)
Location: ALTORF
Tornado F-scale: EF1
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

The tornado primarily produced damage to trees including a few that were uprooted and snapped near the base.  Peak winds were estimated to be 90 mph.  (Tornado 9 of 10).

Tornado in LA SALLE, ILLINOIS
From 22-JUN-15 20:17:00 to 22-JUN-15 20:19:00 (CST-6)
Location: STAVANGER
Tornado F-scale: EF1
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

This tornado was determined based on reports from trained spotters and photos of the damage.  Large trees were snapped and there was minor structural damage to outbuildings.  The tornado had peak winds estimated to 90 mph.  The tornado continued into Grundy County.  (Tornado 6a of 10).

Tornado in LA SALLE, ILLINOIS
From 22-JUN-15 19:50:00 to 22-JUN-15 20:02:00 (CST-6)
Location: PRAIRIE CENTER
Tornado F-scale: EF1
Property damage: 100.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

Several trees were snapped or uprooted, including one tree that fell onto a house.  Peak winds were estimated to be 90 mph.  (Tornado 5 of 10).

Flash Flood in LEE, ILLINOIS
From 22-JUN-15 19:30:00 to 22-JUN-15 23:00:00 (CST-6)
Location: LEE CENTER
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Route 52 at Route 39 was flooded and impassable.

Thunderstorm Wind in KANKAKEE, ILLINOIS
From 22-JUN-15 21:13:00 to 22-JUN-15 21:13:00 (CST-6)
Location: BOURBONNAIS
Magnitude: 70.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

Large branches and a couple trees were blown down.

Tornado in LEE, ILLINOIS
From 22-JUN-15 18:20:00 to 22-JUN-15 18:21:00 (CST-6)
Location: VAN PETTEN
Tornado F-scale: EF0
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

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).

Tornado in KANKAKEE, ILLINOIS
From 22-JUN-15 22:46:00 to 22-JUN-15 22:48:00 (CST-6)
Location: DICKEYS
Tornado F-scale: EF0
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

A tornado briefly touched down but no damage occurred.  The tornado was reported by a trained spotter and law enforcement.  (Tornado 10 of 10).

Tornado in LEE, ILLINOIS
From 22-JUN-15 18:28:00 to 22-JUN-15 18:40:00 (CST-6)
Location: HARMON
Tornado F-scale: EF1
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

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).

Tornado in LA SALLE, ILLINOIS
From 22-JUN-15 19:19:00 to 22-JUN-15 19:24:00 (CST-6)
Location: MENDOTA
Tornado F-scale: EF1
Property damage: 100.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

A tornado crossed through the center of Mendota resulting in significant tree damage.  Some trees were blown down onto structures and at least one fell onto a vehicle.  The tornado touched down near the intersection of Knoll Crest Drive and S Park Avenue where numerous hardwood trees were snapped.  One to three inch branches were broken as the tornado crossed 13th Avenue. A large trunk was split on Washington Street.  Trees were uprooted on 5th Street near 5th Avenue.  Hardwood trees were snapped on N 1st Avenue, including one that fell onto a pickup truck. Maximum winds were estimated to be 105 mph. (Tornado 4 of 10).

Thunderstorm Wind in KANKAKEE, ILLINOIS
From 22-JUN-15 21:20:00 to 22-JUN-15 21:20:00 (CST-6)
Location: UNION HILL
Magnitude: 50.00 EG
Property damage: 1.00K
Crop damage: 0.00K
Reported by: Public

Power poles snapped and fell onto a house near 14000 N and Phillips Road.

Thunderstorm Wind in KANKAKEE, ILLINOIS
From 22-JUN-15 21:36:00 to 22-JUN-15 21:36:00 (CST-6)
Location: KANKAKEE
Magnitude: 50.00 EG
Property damage: 1.00K
Crop damage: 0.00K
Reported by: Public

Trees and a fence were blown down on Old Farm South Court.

Hail in LEE, ILLINOIS
From 22-JUN-15 10:30:00 to 22-JUN-15 10:30:00 (CST-6)
Location: SUBLETTE
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in LA SALLE, ILLINOIS
From 22-JUN-15 10:54:00 to 22-JUN-15 10:54:00 (CST-6)
Location: MENDOTA
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Tornado in GRUNDY, ILLINOIS
From 22-JUN-15 20:45:00 to 22-JUN-15 20:58:00 (CST-6)
Location: PAYTONVILLE
Tornado F-scale: EF3
Property damage: 25.00M
Crop damage: 0.00K
Reported by: NWS Storm Survey

The tornado touched down near Higgins Road and Dupont Road where softwood trees were snapped. The tornado moved east-southeast where trees and power poles were snapped along N Gorman Road.  The most significant damage was noted as the tornado crossed S Carbon Hill Road just south of Division Street, entering Coal City. Dozens of homes were heavily damaged in Coal City with three completely destroyed.  Two of these homes were well built and had at least part of their structure bolted down to the foundation with bolts secured by nuts.  Two high tension metal trusses were downed including one that was crumpled along Hunters Run.  Hundreds of trees were snapped or uprooted.  Numerous utility poles were downed.  Peak winds were estimated to be 160 mph with a max width of three quarters of a mile.  The tornado continued into Will County.  (Tornado 8a of 10).

Tornado in GRUNDY, ILLINOIS
From 22-JUN-15 20:19:00 to 22-JUN-15 20:29:00 (CST-6)
Location: NETTLECREEK
Tornado F-scale: EF1
Property damage: 50.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

This is a continuation of a tornado that began in Lasalle County.  This tornado was determined based on reports from trained spotters and photos of the damage.  Large trees were snapped and there was minor structural damage to outbuildings.  The tornado crossed Interstate-80 near the Seneca Exit.  The tornado had peak winds estimated to 90 mph.  (Tornado 6b of 10).

Thunderstorm Wind in LA SALLE, ILLINOIS
From 22-JUN-15 19:23:00 to 22-JUN-15 19:23:00 (CST-6)
Location: MENDOTA
Magnitude: 70.00 EG
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Public

An outbuilding was damaged along Illinois Highway 251.  A few trees and large branches were blown down in Restland Cemetary.