Stats: Arctic Air Slams US With Frigid Weather

By Grace Muller, AccuWeather.com Staff Writer

January 22,2013; 7:15PM,EST

Right now, the northern United States is experiencing some of the lowest temperatures of the season so far. Why?

From AccuWeather meteorologist Alex Sosnowski's Nasty Cold Wave Heading for Part of the U.S.: A phenomenon known as sudden stratospheric warming occurred in the arctic region during the first week of January. The stratosphere is located between 6 miles and 30 miles above the ground. Often when this occurs, it forces cold air to build in the lowest layer of the atmosphere then to drive southward.

"The polar vortex," or the core of the cold air that was sitting over the North Pole, "split into two last week," AccuWeather meteorologist Henry Margusity said. "It sent one cold air mass into eastern Canada and the northern tier of the United States and another cold air mass to Russia. If you look at temperatures right now, it's colder in eastern Canada than it is as the poles."

Lowest temperatures seen Tuesday morning:

Minnesota

Babbitt -38ºF
Embarrass -36ºF
Crane Lake -35ºF
Ely -33ºF

North Dakota

Langdon -26ºF
Cando -24ºF

Wisconsin

Hayward -23ºF
Siren -20ºF
Tomahawk -20ºF

Michigan

Gwinn -18ºF
Ironwood -17ºF
Sault Ste. Marie -15ºF
Escanaba -15ºF
Iron Mountain -15ºF

Maine

Clayton Lake -30ºF
Presque Isle -26ºF
Frenchville -18ºF