Tornado watch in effect until 11 p.m.

A tornado watch in effect until 11 p.m. tonight has been issued for most of northern Illinois, including Chicago and the surrounding counties.

The National Weather Service has issued the watch for 18 counties including Cook, DuPage, Kane, Lake, McHenry and Will.

The watch also includes five counties in Northwest Indiana.

Also, a flash flood watch remains in effect for the suburbs until 1 a.m. Tuesday, according to the National Weather service.

A second round of storms is expected to hit the area this evening. The storms are capable of producing 1-3 inches of rain, which could cause flash floods.

The watch includes Cook, DuPage, Kane, Lake, McHenry and Will counties.

A round of severe thunderstorms this morning caused headaches for commuters across the area.

Downed trees have been causing delays in Fox Lake, Long Grove and in North Barrington.

High winds forced Metra to stop trains on several lines, which led to cancellations and long delays.

More than 120 flights were canceled at O'Hare airport, with delays stretching to 90 minutes for some flights.