CBS (CHICAGO)–A Winter Weather Advisory is in effect for parts of the Chicago area until 9 a.m. Thursday.

Counties in the advisory area include Boone, DeKalb, Lee, Ogle and Winnebago.

Cook County and most of northern Illinois is under a Hazardous Weather Watch, as deep low pressure will lift northeast across the area Thursday.

Expect periods of freezing rain to cause slippery roads. Allow plenty of time to apply the brakes.

Fog could cause low visibility.

Temperatures will range from the 30s across North Central Illinois to the 50s across far east central Illinois and Northwest Indiana.

Freezing rain could persist across some parts of the Chicago area this morning.

Colder air will move in Friday. It could feel like -10° at O’Hare tomorrow morning, according to CBS 2 meteorologist Megan Glaros.

The weather was affecting driving conditions Thursday morning on area expressways. As of 6:40 a.m., traffic was heavy on the Kennedy Expressway. The left lane of inbound I-90 East was blocked at Addison.