A biting cold blast of Arctic air gripped the northern Great Plains early on Tuesday, bringing dangerous wind chills and the threat of frostbite, weather officials said.
The Arctic air mass was expected to create wind chills of lower than minus 20 degrees Fahrenheit (minus 29 degrees Celsius) over the coming days in the Northern Plains, a region that includes Minnesota and North and South Dakota, according to the National Weather Service.
By the end of the week, the cold air was expected to travel through the Midwest into the mid-Atlantic and Northeast states, the Weather Service forecast said.
Forecasters have said the cold weather snap could be similar to life-threatening lows that parts of the United States saw in 2014 due to a polar vortex, a spinning mass of cold air over the pole that delivers icy Arctic air into the mid-latitudes during the winter whenever the vortex is perturbed and subsequently weakens.
Icy conditions in 2014 snarled travel and thousands of flights were canceled or delayed.
In Fargo, North Dakota, which was expected to experience some of the coldest temperatures among U.S. cities from the latest chill, the mercury had dipped to minus 3 degrees Fahrenheit (minus 19 degrees Celsius) early on Tuesday.
With the wind chill, temperatures in the Fargo area on Tuesday could feel like minus 25 to minus 35 degrees Fahrenheit (minus 32 degrees to minus 37 degrees Celsius), according to an advisory from the local office of the National Weather Service.
In those conditions, frostbite - an injury caused by freezing body tissue - can afflict exposed skin within minutes, according to the Weather Service.
The Detroit and Pontiac office of the Weather Service said in an advisory that the air mass would be the coldest the area has seen since February 2015.
The Weather Service's national advisory said that heavy snow this week could fall in parts of northern Michigan, Pennsylvania and New York state.
(Reporting by Alex Dobuzinskis in Los Angeles; Editing by Tom Heneghan)