CHICAGO -- Weather observations at 6 p.m. indicate that light snow has begun across much of the Chicago area, and will continue to cross the area in waves throughout the weekend, possibly bringing well over a foot of snow to some areas of Chicagoland.
A Winter Storm Warning calling for as much as 10 to 15 inches of snow in counties along and north of the Interstate-80 corridor is in effect from 6 p.m. Thursday to 9 p.m. Friday.
The heavy band of snow will be spreading over northern Illinois into the morning commute Friday, but will become more occasional later into the morning. It may even stop at times. However, another wave will return in time for the evening commutes on Friday and into Saturday morning.
At times, travel will be "very difficult to impossible," the National Weather Service in Chicago tweeted on Thursday. Avoid or minimize travel during this time period, if possible.
Snow will spread into our area from the west in north-central Illinois and into the Chicago Metro area, quickly beginning to accumulate and making roads snow-covered/slick toward the end of the evening commute. By midnight snowfall totals could easily be between three and four inches, and could reach six to 10 inches by 6 a.m. Friday.
Accumulations will continue Friday, impacting both the morning and evening commute with snow gradually diminishing and ending from the west Friday evening.
The core of the heaviest snow will likely lay-out between Interstate-88 and Interstate-90 including Chicago – many locations could end up with more than a foot of snow. Snow will extend north into the southern portions of Wisconsin and Lower Michigan, while snow totals will taper off quickly in areas well of Chicago from Kankakee County south.
The center of the storm system is tracking east-southeast out of Montana and South Dakota pretty well following along and north of the Interstate-80 corridor through Iowa, Illinois and Indiana.