Frigid air will blast southward onto the northern Plains today sendingtemperatures plummeting. Temperatures will fail to warm above zero today andMonday in parts of Montana and the Dakotas, and overnight lows will bedangerously cold.As the core of the cold air shifts eastward early in the week, lake-effect snowshowers will start up once again in the typical downwind areas of the GreatLakes. Feet of snow buried parts of the region last week as a similar shot ofarctic air swept in. Several more inches of snow will pile up in these areaseach day from Tuesday to Thursday.

Story By AccuWeather.com Meteorologist Katie Storbeck.