The record-setting cold snap that has nearly two-thirds of the nation in its grips has its roots in what is referred to as a polar vortex. But what on Earth is that?
The article below from NBCNews.com breaks it down:
By Erik Ortiz, Staff Writer, NBC News
Move over, haboob. See you next summer, heat dome. The weather phenomenon hogging all the attention now is “polar vortex.”
Twenty-six states are under wind-chill warnings or watches, and the polar vortex is to blame, breaking loose from its North Pole confines and plunging the country in a deep, dangerous freeze.
It isn’t expected to linger for long but will leave a mark. Here’s what you need to know:
NOAA via AP
NOAA satellite image taken Monday, Jan. 6 at 01:45 a.m.
So what exactly is a polar vortex?
A polar vortex is basically a great swirling pool of extremely cold air located tens of thousands of feet in the atmosphere, said Frank Giannasca, senior meteorologist with The Weather Channel.
Basically an arctic cyclone, it ordinarily spins counterclockwise around the north and south poles.
While it tends to dip over northeastern Canada, it’s catching everyone’s attention because it has moved southward over such a large population — as many as 140 million Americans are feeling the freeze.
Why has it traveled so far south?
There’s a variety of reasons why a chunk of cold air over Canada would break off our way.