Severe thunderstorms moved across parts of northern Illinois during the middle to late evening hours of July 18th.  Some of the storms produced torrential rainfall which produced rainfall rates of 1 to 2 inches per hour which resulted in flooding in some areas.

Flash Flood in COOK, ILLINOIS
From 18-JUL-12 20:45:00 to 18-JUL-12 22:30:00 (CST-6)
Location: GLENCOE
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Hazel Avenue under a viaduct was closed due to high water.

Hail in BOONE, ILLINOIS
From 18-JUL-12 18:17:00 to 18-JUL-12 18:18:00 (CST-6)
Location: BLAINE
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Nickel size hail was reported near the intersection of Popular Grove and Blaine Roads.

Thunderstorm Wind in OGLE, ILLINOIS
From 18-JUL-12 18:57:00 to 18-JUL-12 18:57:00 (CST-6)
Location: STILLMAN VLY
Magnitude: 61.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Wind gusts were estimated to 70 mph about 5 miles southwest of the Rockford Airport.  Small tree limbs were blown down.

Thunderstorm Wind in WINNEBAGO, ILLINOIS
From 18-JUL-12 18:58:00 to 18-JUL-12 18:58:00 (CST-6)
Location: SHIRLAND
Magnitude: 55.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A large tree limb was blown down on Highway 75 about 4 miles east of Durand.

Thunderstorm Wind in WINNEBAGO, ILLINOIS
From 18-JUL-12 19:06:00 to 18-JUL-12 19:06:00 (CST-6)
Location: CHERRY VLY
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Wind gusts were estimated to 65 mph.  Large tree limbs were blown down.

Thunderstorm Wind in WINNEBAGO, ILLINOIS
From 18-JUL-12 19:20:00 to 18-JUL-12 19:20:00 (CST-6)
Location: MACHESNEY PARK
Magnitude: 55.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Amateur Radio

A 20 to 30 foot long, six inch diameter tree limb fell through the roof of a house on Mildred Road.

Hail in BOONE, ILLINOIS
From 18-JUL-12 19:24:00 to 18-JUL-12 19:25:00 (CST-6)
Location: CAPRON
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Thunderstorm Wind in MCHENRY, ILLINOIS
From 18-JUL-12 19:34:00 to 18-JUL-12 19:34:00 (CST-6)
Location: HEBRON
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A 4 to 6 inch diameter tree was blown down on Route 173, just east of Hebron.

Thunderstorm Wind in DE KALB, ILLINOIS
From 18-JUL-12 19:40:00 to 18-JUL-12 19:40:00 (CST-6)
Location: MALTA
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Wind gusts were estimated to 60 mph near Interstate 88 and University Road.

Thunderstorm Wind in KANE, ILLINOIS
From 18-JUL-12 20:12:00 to 18-JUL-12 20:12:00 (CST-6)
Location: CARPENTERSVILLE
Magnitude: 55.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

An eight inch diameter tree was blown down along with six inch diameter tree limbs.

Thunderstorm Wind in KANE, ILLINOIS
From 18-JUL-12 20:15:00 to 18-JUL-12 20:15:00 (CST-6)
Location: ELGIN
Magnitude: 52.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Thunderstorm Wind in COOK, ILLINOIS
From 18-JUL-12 20:25:00 to 18-JUL-12 20:25:00 (CST-6)
Location: INVERNESS
Magnitude: 61.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Wind gusts were estimated to 70 mph.

Thunderstorm Wind in COOK, ILLINOIS
From 18-JUL-12 20:32:00 to 18-JUL-12 20:32:00 (CST-6)
Location: STREAMWOOD
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Wind gusts were estimated to 65 mph near Barrington and Schaumburg Roads.

Thunderstorm Wind in KANE, ILLINOIS
From 18-JUL-12 21:23:00 to 18-JUL-12 21:23:00 (CST-6)
Location: AURORA MUNI ARPT
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Tree limbs 6 to 8 inches in diameter were blown down near Galena Blvd and Fordham Avenue.

Thunderstorm Wind in COOK, ILLINOIS
From 18-JUL-12 21:25:00 to 18-JUL-12 21:25:00 (CST-6)
Location: GOESELVILLE
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Amateur Radio

Wind gusts were estimated to 60 mph near 159th Street and Harlem Avenue.

Flood in WINNEBAGO, ILLINOIS
From 18-JUL-12 19:09:00 to 18-JUL-12 22:00:00 (CST-6)
Location: ROCKFORD
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Ten to twelve inches of water was reported at the intersection of Court and West State Streets.

Flood in WINNEBAGO, ILLINOIS
From 18-JUL-12 19:24:00 to 18-JUL-12 22:00:00 (CST-6)
Location: EAST ROCKFORD
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Amateur Radio

Four inches of flowing water was reported near 7th Street and Broadway.

Flood in LAKE, ILLINOIS
From 18-JUL-12 20:06:00 to 18-JUL-12 22:00:00 (CST-6)
Location: GRASS LAKE
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Four inches of standing water was reported on Route 59, about one eighth of a mile north of Petite Lake Road.

Flood in COOK, ILLINOIS
From 18-JUL-12 20:25:00 to 18-JUL-12 22:30:00 (CST-6)
Location: HANOVER PARK
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Five inches of water was reported going over curbs on Forest Cove Court.

Thunderstorm Wind in KANE, ILLINOIS
From 18-JUL-12 20:25:00 to 18-JUL-12 20:25:00 (CST-6)
Location: ELGIN
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Wind gusts were estimated to 60 mph.  Small tree limbs were blown down.

Thunderstorm Wind in WINNEBAGO, ILLINOIS
From 18-JUL-12 18:58:00 to 18-JUL-12 18:58:00 (CST-6)
Location: LOVES PARK
Magnitude: 55.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Amateur Radio

A ten inch diameter tree limb was blown down on the 700 block of Loves Park Drive and an eight inch diameter tree limb was blown down on the 7800 block of Forest Hills Road.