The first major winter snow storm has hit the Midwest region of the U.S., blanketing from Milwaukee to Chicago with snow as far as St. Louis and the northeast and cancelling hundreds of flights at O'Hare and Midway airports on Thursday.

After a mild winter with La Nina hovering over Canada, snow has arrived and will continue in eastern Iowa, Wisconsin, Illinois, Indiana and Michigan, according to MSNBC, where warnings are in effect.

Snowfall began in Chicago around 9:30 a.m. and the National Weather Service predicted up to four and eight inches for Chicago, and a foot in certain areas lying east of Lake Michigan. Between two and five inches are expected in central Illinois, with icy and snowy roads reported in Freeport, the Quad Cities, Bloomington and Jacksonville.

Slick sheets of ice were reported in St. Louis, Missouri with winds up to 30 mph and mild snow.

According to ABC News in Chicago, about 100 flights between 1 p.m. and 6 p.m. on Thursday were cancelled at Midway, in addition to more than 300 at O'Hare. Significant delays averaging about 20 minutes at the airports were reported, as well.

The Chicago Tribune reported snow accumulation figures as of mid-afternoon Thursday in the area: Bartlett, 1.4 inches; Mendota, 2.5 inches; Arlington Heights, 1.6 inches; Montgomery, 1.7 inches; Schaumburg, 1.2 inches; Crest Hill, 2.3 inches; Harvard, 1.2 inches; Franklin Park, 1.5 inches; Palatine, 2 inches; St. Charles, 1.5 inches; Carol Stream, 1.6 inches; Ravenswood neighborhood on north side of Chicago. 1.2 inches; Matteson; 1.2 inches; Yorkville, 2.1 inches, Chicago Ridge, 2.5 inches; Elburn, 3.1 inches.

Last January, Chicago was blanketed with 13 inches of snow.

Some of the snow extended as far as the northeast region of the U.S. with eight inches in the southern Adirondacks and winter weather advisories between Pennsylvania and the Great Lakes, according to USA Today. Winter weather is expected to sweep Buffalo and the New England region through Friday.