Heavy storms hit the Chicago area and sent these pedestrians running for cover near Southport and Addison. | Al Podgorski~Chicago Sun-Times
Updated: May 25, 2011 4:13PM
As much as 2 1/2 inches of rain have fallen in less than three hours in some parts of the Chicago area Wednesday morning, and there was at least one confirmed report of a tornado in Kankakee County.
South and southwest suburban counties are under a tornado watch and airlines have canceled more than 400 flights Wednesday morning. In addition to the tornado reported Wednesday morning in St. Anne, a town of about 1,200 residents which is approximately 50 miles south of Joliet, the National Weather Service has gotten unconfirmed reports of tornadoes touching down in northwest Indiana.
According to storm reports from the weather service, the heaviest rains so far Wednesday morning were in Will County, where 2.54 inches of rain fell in Mokena between 7 a.m. and 10 a.m.; and 2.26 inches of rain fell in Peotone between 7 a.m. and 10:30 a.m.
In Lake County, Ind., there was minor flooding and .69 inches of rain had fallen in Crown Point between 7:30 a.m. and 9 a.m., according to the weather service.
Trees were down and funnel clouds were reported in Rensselaer, Ind., and the surrounding area, according to the weather service. A weather service meteorologist said while they have “several reports of tornadoes” touching down Wednesday morning, the only one that had been confirmed was in St. Anne. According to the weather service a house was damaged by that tornado. Fire personnel reported that tornado to the weather service about 9:15 a.m. The Kankakee County Sheriff’s Office confirmed that report, but could not immediately provide details on the damage as of about 1:30 p.m.
Elsewhere in the area, according to weather service reports, quarter-inch hail was reported in Kankakee; a house was reportedly struck by lightning in DeKalb; there was street flooding in Glen Ellyn; 1.52 inches of rain had fallen within three hours in Lisle; and 1.50 inches of rain had fallen at Midway Airport between 7:30 a.m. and 10:30 a.m.
Rain and low visibility has caused airlines at O’Hare to cancel more than 400 flights as of 7:40 a.m., according to the city Department of Aviation. Flights in and out of O’Hare are delayed up to one hour, while Midway Airport is experiencing some delays and “a few” cancellations.
The line of thunderstorms lifted Wednesday morning but was expected to redevelop in the afternoon and move from southwest to northeast across the Chicago area, according to the weather service. Severe thunderstorms are most likely to occur south of I-80 in northeastern Illinois and northwest Indiana.
The strongest storms could produce nickel-sized hail, 60 mph wind gusts, frequent cloud-to-ground lightning and heavy rainfall, the weather service said.
The conditions also have the potential to create an isolated tornado, likely south of I-80.
“We’re watching area rivers, especially the Kankakee and Iroquois rivers, due to the heavy rainfall,” the meteorologist said. Another 1 to 2 inches of rain was possible in these areas within the next 224 hours, he said.
Downtown Chicago could see between a half-inch and three-quarters of an inch of rain.
Thunderstorms will continue into Thursday and possibly into Memorial Day weekend as the storm system slowly moves eastward into central Indiana, the weather service said.
Waves measuring 12 to 18 feet and winds of up to 35 mph on Lake Michigan will also make conditions hazardous for boaters and small vessels early Thursday into Friday, the weather service said. A small craft warning will be in effect from 1 a.m. Thursday to 10 a.m. Friday.