MILWAUKEE - Another band of arctic air is descending into the northern U.S., bringing a wave of frigid temperatures expected to linger for most of the week.
Temperatures plunged below zero in North Dakota and northern Minnesota on Monday morning. The cold front is expected to expand south into Iowa and as far east as Maine by Tuesday night, and will remain entrenched through Thursday.
National Weather Service meteorologist Paul Collar says the bitterly cold blast will lead to a swath of subzero temperatures, with highs in the single digits and wind chills of minus 20 or colder.
He says portions of Minnesota, Vermont, New Hampshire and Maine are under wind chill warnings. He says the cold will be challenging but not as bad as the recent polar vortex.