Chicago airports cancel many flights ahead of weather

CHICAGO -- Chicago's two biggest airports are already experiencing delays and have canceled flights ahead of inclement weather Thursday.

O'Hare is experiencing 30-minute delays for both inbound and outbound flights and has canceled 250 flights.

Midway is experiencing delays of about 40 minutes and canceled 220 flights.

Southwest canceled all flights after noon Thursday.

ABC7 meteorologist Tracy Butler says rain will likely start falling in the late afternoon at the earliest.

Butler says the heaviest rain will likely be falling along and south of that I-80 corridor. The northern suburbs most likely will get the lesser amounts of rain, she said.

However, since just about the entire is under a slight risk of severe storms, it's possible that any storms that develop could become severe, with large hail and strong winds being the main threat, Butler said.

The main severe threat would most likely be during the mid and late evening hours.