The National Weather Service Chicago warned on Twitter that more snow storms are developing across Northwestern Illinois, and will drift eastward across much of Northeastern Illinois and Northwestern Indiana on Friday afternoon.
It's also snarling traffic and closing some freeways.
Chicago's metropolitan area was blanketed with its heaviest snowfall since at least late 2016 as the storm put an icy grip on much of Wisconsin, northern IL and MI.
A section of Interstate 94 in southwestern MI was blocked after dozens of vehicles crashed.
"Ingham Co.is saying that 4-7" is a pretty good bet for northern parts of the county with heavier amounts in the southern half, which could see 5-9", maybe even 10 plus inches.
National Weather Service meteorologist Brian Hurley said on Friday that the system was likely to drop another four or five inches (10 or 12.5 cm) of snow on the Midwest as it headed east toward New England.
Portions of northern IN were hit hard, with 8 inches reported IN New Carlisle.
Chicago was forecast to receive as much as 14 inches of snow with Detroit expecting up to 9 inches.
Crashes were reported, including a multi-vehicle smashup that closed a stretch of eastbound Interstate 94 near Ann Arbor.
About 980 flights were canceled at Chicago's O'Hare International Airport and more than 300 flights were canceled at Midway, the Chicago Department of Aviation reported Friday morning.
By early Friday, more than 100 flights were canceled at Detroit Metropolitan Airport in Romulus, Michigan. Court closings were reported in Chicago and Detroit, and driver's license offices were shut in the Chicago area.
About 800 flights have been canceled in the Chicago area as heavy snowfalls hit the US Midwest overnight, media reported on Friday.
The worst snowfall will occur in the northern part of Chicago, while areas farther south will have extremely limited visibility, forecasters said.
Early Friday, the National Weather Service received reports of 4 inches (10 centimeters) of snow in northern IL.
A powerful winter storm slammed the Midwest on Friday, blanketing cities in snow and causing a number of school cancellations. People should stay off the roads if possible, but if they drive they should expect delays and hazardous conditions.
Midwest residents often boast that they are well prepared for winter weather and school is rarely called off.
City officials announced school closures in Chicago, Detroit and Milwaukee.
"The Friday morning rush is gonna be trouble", National Weather Service meteorologist Charles Mott had told the Chicago Tribune. Classes were also canceled in the city's suburbs.