(CNN) -- Much of the upper Midwest battled blizzard conditions Saturday, with a combination of heavy snow, fierce winds and sub-zero temperatures pummeling the region 10 days before the official start of winter.
A blizzard warning, issued by the National Weather Service, stretched from South Dakota to Wisconsin and down to Missouri and Illinois. The storm was expected to dump between 15 and 20 inches of snow in some locales.
The storm will likely gain strength during Saturday, before bearing down on the Chicago, Illinois, area, the weather service said.
Even before the current storm, Minneapolis and St. Paul, Minnesota, this season have had 16.7 inches of snow as of the first week of December. Some areas to the west and south have had more, including 22.9 inches in Chanhassen, the National Weather Service said.
More snow came Saturday, with another 7 to 11 inches forecast through the afternoon. The precipitation should taper off by evening, the weather agency said, with temperatures dropping to 8 degrees below zero.
(Complements of CNN.com)