Snow has begun to cover the area and it'll be a while before it clears up. Take public transportation if at all possible.
A Winter Weather Advisory is in effect from now until 6 a.m. Saturday (look at interactive weather map).
[Chicago-Area Traffic Times | Amtrak | O'Hare International | Midway International | Gary-Chicago International | Metra | CTA]
Significant snowfall will move into northeast Illinois and extreme Northwest Indiana during the very early morning Friday and persist through Friday and Friday night into early Saturday morning. Periods of heavier snowfall are expected to occur Friday morning and again from later Friday afternoon through Friday evening.
Areas to the north are likely to see most of the snowfall.
Total snow accumulation by Saturday will range from 4 inches from a line from Valparaiso Indiana to Yorkville Illinois to 8 inches along the Wisconsin border.
A Winter Weather Advisory for snow means that accumulating snow will cause primarily travel difficulties. Be prepared for snow covered roads and limited visibilities and use caution while driving.