Commuters should expect "slow and slippery" road conditions Monday afternoon into the evening after a winter weather advisory for parts of northeastern Illinois was extended.The advisory, which covers central and northern Cook County and DuPage County, was originally in effect until 4 p.m. but was extended to 9 p.m., according to the National Weather Service. Brett Borchardt, a senior meteorologist with the weather service, said the advisory was extended because of a band of lake-effect snow in southeast Wisconsin that's expected to move south along the lakeshore Monday evening. "We wanted to make sure we had the advisory out [during] the evening commute when there could be snow falling on roads, making for a slippery and slow commute," Borchardt said. The counties under advisory were all expected to see some snowfall with the highest totals — about 1 to 2 inches — expected closer to Lake Michigan, according to the weather service. Temperatures are expected to slip into the high teens Monday night causing any precipitation to stick to surfaces. "Anything that's untreated, whether that's a roadway, a sidewalk or a parking lot, that's going to be pretty slick today," Borchardt said. Chilly temperatures will continue through the remainder of the workweek. We’re keeping an eye on the Friday to Saturday timeframe for the next threat for snow in the general region. Until then, bundle up when heading outdoors! #ILwx #INwx pic.twitter.com/53zGDQmH20— NWS Chicago (@NWSChicago) January 6, 2025 A Jeep and Mount Prospect Park District school bus carrying 51 students and seven adult administrators collided shortly before noon on I-290 eastbound near I-390 in Itasca, according to the Illinois State Police. One of the adult school bus passengers was taken to a nearby hospital after the crash; no other injuries were reported.Slippery conditions also caused a temporary ground stop at O'Hare Airport on Monday morning. About 284 flights were canceled at O'Hare and about 836 flights were delayed as of midday, according to FlightAware. At Midway, 39 flights were canceled and 150 flights were delayed as of the early afternoon.Borchardt advises commuters to "prepare for slow travel times and be extra careful.""Increase your following distance between you and the cars in front of you," Borchardt said. "Give road crews as much space as we can as they're cleaning the roads.""Just take it slow out there." Lake effect snow and patchy drizzle continues across parts of the Chicago metropolitan area. Untreated roads may become slippery this evening as temperatures remain below freezing. #ILwx #INwx pic.twitter.com/cWCSZacLFE— NWS Chicago (@NWSChicago) January 6, 2025