Back in the day, we used to call it "winter."
Now, it's got its own catchphrase: the polar vortex, which could be making a return engagement to the U.S. later this month or in January.
Or maybe it won't.
Regardless, the polar vortex – everyone's favorite wintertime whipping boy – is a large area of cold air high up in the atmosphere that normally spins over the North Pole (as its name suggests). Sometimes, however, thanks to a meandering jet stream, some of the vortex can slosh down into North America, helping to funnel unspeakably cold air down here where we all live.
And it's not exactly a new phenomena, either, despite how hashtag-friendly it is.
The vortex has likely "existed in some form for the past 4.5 billion years," according to senior scientist Jeff Kiehl of the National Center for Atmospheric Research in Boulder, Colorado. Although it's been understood by scientists for several decades and referred to in meteorological literature in the 1950s, it only entered the popular lexicon as a synonym for miserably cold winter weather a few years ago.
https://www.usatoday.com/story/news/nation/2018/12/18/polar-vortex-bitter-cold-wave-could-its-way-arctic/2348767002/
