Strong to severe thunderstorms moved across many areas of northern Illinois during the afternoon and evening hours of May 11th.

Flood in KANE, ILLINOIS
From 11-MAY-11 16:35:00 to 11-MAY-11 17:00:00 (CST-6)
Location: CARPENTERSVILLE
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Amateur Radio

The intersection of Dundee Road and Golfview Lane was flooded.  Two inches of rain fell over the hour leading up to this report.

Thunderstorm Wind in GRUNDY, ILLINOIS
From 11-MAY-11 17:15:00 to 11-MAY-11 17:15:00 (CST-6)
Location: MORRIS
Magnitude: 55.00 EG
Property damage: 4.00K
Crop damage: 0.00K
Reported by: Amateur Radio

Eight power poles were blown down at Ashton Road and Interstate 80.

Thunderstorm Wind in GRUNDY, ILLINOIS
From 11-MAY-11 17:40:00 to 11-MAY-11 17:40:00 (CST-6)
Location: MAZON
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Amateur Radio

A tree fell blocking the road at Route 47 and Gardner Road.

Hail in WILL, ILLINOIS
From 11-MAY-11 18:05:00 to 11-MAY-11 18:07:00 (CST-6)
Location: CREST HILL
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Thunderstorm Wind in COOK, ILLINOIS
From 11-MAY-11 18:40:00 to 11-MAY-11 18:40:00 (CST-6)
Location: HOMETOWN
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Wind gusts were estimated to 60 mph.

Hail in MCHENRY, ILLINOIS
From 11-MAY-11 14:55:00 to 11-MAY-11 14:56:00 (CST-6)
Location: SPRING GROVE
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in MCHENRY, ILLINOIS
From 11-MAY-11 15:10:00 to 11-MAY-11 15:10:00 (CST-6)
Location: SPRING GROVE
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Quarter size hail was reported at the intersection of Route 173 and Wilmot Road.

Hail in MCHENRY, ILLINOIS
From 11-MAY-11 15:20:00 to 11-MAY-11 15:22:00 (CST-6)
Location: CRYSTAL LAKE
Magnitude: 1.50 
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Walnut size hail was reported at the intersection of Main Street and Route 14 causing damage to cars.

Hail in MCHENRY, ILLINOIS
From 11-MAY-11 15:24:00 to 11-MAY-11 15:26:00 (CST-6)
Location: LAKE IN THE HILLS
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in MCHENRY, ILLINOIS
From 11-MAY-11 15:49:00 to 11-MAY-11 15:52:00 (CST-6)
Location: CRYSTAL LAKE
Magnitude: 1.50 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in WINNEBAGO, ILLINOIS
From 11-MAY-11 16:04:00 to 11-MAY-11 16:06:00 (CST-6)
Location: DURAND
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in MCHENRY, ILLINOIS
From 11-MAY-11 16:04:00 to 11-MAY-11 16:06:00 (CST-6)
Location: MC HENRY
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Quarter size hail was reported at Route 120 and Route 31.

Hail in MCHENRY, ILLINOIS
From 11-MAY-11 16:37:00 to 11-MAY-11 16:39:00 (CST-6)
Location: WOODSTOCK
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Dime to nickel size hail was reported at the intersection of Route 14 and Route 47.

Hail in LA SALLE, ILLINOIS
From 11-MAY-11 16:42:00 to 11-MAY-11 16:44:00 (CST-6)
Location: OGLESBY
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Nickel to quarter size hail was reported at Interstate 39 and Route 251.

Hail in COOK, ILLINOIS
From 11-MAY-11 17:00:00 to 11-MAY-11 17:01:00 (CST-6)
Location: NORTHBROOK
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Penny size hail was reported at the intersection of Waukegan Road and Shermer Road.

Flood in MCHENRY, ILLINOIS
From 11-MAY-11 14:55:00 to 11-MAY-11 16:00:00 (CST-6)
Location: RICHMOND
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Heavy rain caused 8 to 12 inches of standing water over Route 12 near Route 173.

Thunderstorm Wind in COOK, ILLINOIS
From 11-MAY-11 18:50:00 to 11-MAY-11 18:50:00 (CST-6)
Location: CHICAGO LAWN
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Several trees were reported down near West 65th Street and South Oakley Avenue.

Thunderstorm Wind in COOK, ILLINOIS
From 11-MAY-11 18:20:00 to 11-MAY-11 18:20:00 (CST-6)
Location: WILLOW SPGS
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Several trees were reported down at the Little Red School House.

Flood in KANE, ILLINOIS
From 11-MAY-11 16:11:00 to 11-MAY-11 17:00:00 (CST-6)
Location: PLATO CENTER
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Four inches of water was reported on Route 47, approximately a quarter mile north of Plato Center.

Hail in MCHENRY, ILLINOIS
From 11-MAY-11 15:31:00 to 11-MAY-11 15:34:00 (CST-6)
Location: LAKE IN THE HILLS
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail up to nickel size was reported across Lake in the Hills, including nickel size hail at the intersection of Randall Road and Algonquin Road, and dime size hail at the intersection of Randall Road and Ackman Road.

Hail in COOK, ILLINOIS
From 11-MAY-11 18:47:00 to 11-MAY-11 18:55:00 (CST-6)
Location: HOMETOWN
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Several reports of hail up to the size of quarters were received from the southern Chicago metro area.  These reports include penny size hail in Hometown and quarter size hail reports in Evergreen Park and at the Interstate 94 and West 95th Street intersection.

Thunderstorm Wind in MCHENRY, ILLINOIS
From 11-MAY-11 14:39:00 to 11-MAY-11 14:39:00 (CST-6)
Location: BELDEN
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Estimated wind gusts of 55 to 60 mph occurred on Okeson Road approximately one half a mile west of Greenwood Road.

Flood in MCHENRY, ILLINOIS
From 11-MAY-11 15:49:00 to 11-MAY-11 16:30:00 (CST-6)
Location: CRYSTAL LAKE
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

The intersection of Main Street and Berkshire Road was flooded after heavy rains fell across the area.  A spotter in Lake in the Hills reported 2.45 inches fell in 90 minutes.

Hail in KANE, ILLINOIS
From 11-MAY-11 15:17:00 to 11-MAY-11 15:18:00 (CST-6)
Location: UNIDA
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Quarter size hail was reported at the intersection of Plank Road and Route 20.

Thunderstorm Wind in KENDALL, ILLINOIS
From 11-MAY-11 17:54:00 to 11-MAY-11 17:54:00 (CST-6)
Location: OSWEGO
Magnitude: 60.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter