
The worst of the icy weather will centre on the upper Midwest, the Climate Prediction Centre predicts.
"Record cold temperatures are possible for the High Plains, Upper Midwest and Great Lakes later this week," the US National Weather Service said in an online forecast.
There are reports that Minneapolis has been hit by temperatures 10 to 20 degrees below normal, with current reports stating that it is -16 C.
Cities including Chicago, Detroit and Buffalo, are also expected to experience unusually low temperatures, with the mercury in some areas dropping by as much as 40 degrees to below 0 C by midweek, according to AccuWeather.
"The polar vortex is essentially a mass of very cold air that usually hangs out above the Arctic Circle and is contained by strong winds," AccuWeather meteorologist Alex Sosnowski told USA Today.












Comment: For some background on Michael Mann read:
Dr. Michael Mann's dishonest political messaging
Climategate: Michael Mann's very unhappy New Year
Climategate Junk Scientist Michael Mann Awarded Half a Million in Stimulus Cash