Subzero cold is plunging south and eastward across the Prairies of Canada, sending temperatures plummeting across the Plains and the Upper Midwest. A large arctic high will build across these areas through the first half of the week, continuing to cause temperatures to drop.

A harsh, gusty breeze will contribute to even colder AccuWeather.com RealFeel® temperatures across the Dakotas, Minnesota and Iowa today.

Chicago will fall under the frosty grip on Tuesday and Wednesday, as daytime temperatures will hold in the 20s with AccuWeather.com RealFeel Temperatures near 0 F.

By Wednesday, the mild air gripping the Northeast will be swept away by much colder air. However, the brutally cold air will moderate from the extreme values impacting the northern Plains and the Upper Midwest.

In crossing the Great Lakes, the cold, northwesterly wind flow will spark outbreaks of heavy, lake-effect snow between Tuesday and Thursday.

Story by AccuWeather.com Meteorologist Meghan Evans.