CHICAGO (CBS) — Snow began falling in the Chicago area Monday right before the evening rush and the fast moving sytem could bring up to six more inches of snowfall.

A Winter Weather Advisory was issued for portions of north central and northeast Illinois, in effect from noon to midnight Tuesday.

CBS 2’s Charlie De Mar was in the Mobile Weather Lab, following a band of snow around Bolingbrook just as the evening rush hour kicked into high gear. A light, fluffy snow was falling steadily.

As of noon, airlines at O’Hare proactively canceled about 400 flights. Airlines at Midway have cancled about 20 flights.

The city’s Department of Streets and Sanitation has deployed 287 plows for the evening rush hour. Cole Stallard said the challenge will be the timing: the heaviest snow is expected between 5 p.m. and 8 p.m., when traffic is heavy as well.

Drivers should use caution while traveling and “be prepared for snow-covered roads and limited visibilities,” the National Weather Service said.

Additional snowfall is again likely across the area Tuesday night and into Wednesday morning. The snow could pick up again Thursday night, lasting through Friday night.

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