About 20,000 homes and businesses served by Commonwealth Edison Co. were without power this afternoon in the wake of severe thunderstorms that pelted the Chicago area with golf ball-size hailstones, disrupted Metra service for hours in the far northern suburbs and damaged 64 Chicago police cars.



At the peak of the storm at 9 p.m., 100,000 of the utility's customers were without electricity.



As of 10 a.m., the bulk of the power outages were in the northern suburbs with 15,000. About 1,250 in the southern suburbs were affected, 3,100 in Chicago, and 70 in the western suburbs.



ComEd said about 80 percent of all power had beeen resand the near west suburbs and only 100 in the farther western suburbs, said ComEd spokeswoman Arlana Johnson.



It was the second major storm-related outage in less than two weeks, although not as widespread. The earlier storm left 440,000 without power, and it took several days to restore everyone. But this repair effort seemed to be moving more quickly, although the utility said it may be Saturday until it is completed.



The National Weather Service said some of its spotters reported funnel clouds in Wadsworth Lake, North Chicago and at Great Lakes Naval Station. Damaged boats with torn sails were reported in the North Point Marina in Withrop Harbor. Mobile campers sustained damage atZion Beach State Park.



In Lake County this morning, Sheridan Road was closed in both directions between Greenwood Avenue and Illinois Highway 173 by downed trees and wires.



Earlier, on Metra's Union Pacific North Line, both inbound and outbound trains stopped for up to four hours by downed electric power wires and trees across the tracks near Waukegan.



But tracks were cleared shortly before 4 a.m., said Metra spokesman Tom Miller, and the morning rush hour was expected to be almost normal, with only inbound train No. 300 experiencing a delay of 20 to 25 minutes caused by late-arriving equipment.



The hail damaged 64 Chicago Police squad cars parked at Area 4 headquarters, 3151 W. Harrison St. Damage ranged from dents to smashed windows to roof light bars, police said.



Forty-five cars with glass damage will have to be removed temporarily from the streets, said Lt. John Andrews, "but will it impact police service? Absolutely not." He said cars from other districts could be reallocated if necessary, but that need hadn't arisen.



The temporary loss of the cars won't hurt the department's ability to put a full force on the streets, said Lt. John Andrews.



In Kenosha, Wis., a 31-year-old motorcyclist was killed when a tree felled by winds between 70 and 80 mph hit him as he was riding, according to the Kenosha County Sheriff's Department.



The 31-year-old man was riding his motorcycle on a local road at 8:12 p.m. when he was struck by the tree, according to a news release from the Kenosha County Sheriff's Department. He was later pronounced dead at a hospital.



Two other residents were injured when they touched live electrical wires, and a woman was treated for a broken hip after she was struck by debris from a shed, authorities said.



"We are continuing to assess the damage in the city," said Kenosha Mayor Keith Bosman. "It may take several days to clean-up debris."



The storm raced down through Lake Michigan coastal communities, ducking further inland before reaching Chicago and losing strength once it moved into Indiana, said David Beachler, a meteorologist with the National Weather Service in Chicago. He said a gauge on the beach in Waukegan Harbor just south of the Wisconsin border registered a hurricane-strength wind gust of 94 mph.



David Mann, a manager at Batten International Airport inRacine, Wis., said a wind gauge there registered a gust of 82 mph and that the storm caused a C130 military plane on display to pivot 45-50 degrees.



As the storm moved southward into Chicago, it dumped heavy rain and hail the size of golf balls and even baseballs, said Casey Sullivan, a weather service meteorologist.



Lake County Emergency Management Agency coordinator Kent McKenzie said the storm felled trees into buildings and power lines, and that there were several reports of trees damaging recreational vehicles camped at Illinois Beach State Park, north of Waukegan. Emergency workers freed several people trapped by a tree in a vehicle at the park, but no one was hurt, McKenzie said.



In Chicago, hail was reported in the East Garfield Park and Little Village neighorhoods, and hail the size of a nickel to a quarter in diameter was reported at the corner of Lincoln and Cullom avenues on the North Side.



Associated Press contributed