WaPo: Where some of the coldest air of the season will hit in the U.S. this week
WaPo - (archived: https://archive.ph/WoZJB ) Where some of the coldest air of the season will hit in the U.S. this week
Around 60 million people are forecast to experience subzero temperatures this week. The polar vortex may also fuel yet another snow and ice storm in coming days.

By Ben Noll
A lobe of the polar vortex, a ring of freezing air typically found near the North Pole, will once again move into the central and eastern states this week, bringing some of the coldest air of the winter season so far — and even helping fuel yet another winter storm in coming days.
Around 60 million people are expected to experience subzero temperatures across the United States from Montana to Maine and as far south as Oklahoma. Around 20 states can expect wind chill values below minus-20, low enough to cause frostbite in less than 30 minutes.
The level of cold may be record-breaking for some central and southern states, especially from Wednesday through Friday.
As the frigid air clashes with a warmer, moist flow of air from the Gulf of Mexico, a storm will form in the Plains on Tuesday and track to the East Coast by Thursday.
A swath of accumulating snow and/or ice will hit more than 15 states. The conditions may lead to treacherous travel, flight delays and cancellations, and more school closures — including in several states that experienced deadly flooding over the weekend.
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