Dusting off the old meme I made a few years back, last time the Polar Vortex attacked North America:
And yes, regardless of any dispute about the term “Polar Vortex” itself (there is some confusion and disagreement), the excursion of air masses that normally reside in a particular latitudinal region (i.e, tropical, temperate, polar) can be, and likely is, caused by the effects of human release of greenhouse gasses. Ironically, the sequence of steps that go from your local coal plant or the back end of your excessively large car to an attack by the polar vortex involves a warming of the Arctic. So, I suppose, the polar air we are at present being assaulted with could be worse.
Simply put, as the Arctic warms, the age-old and somewhat complex process of heat moving from the warm equatorial regions to the poles (which you know it has to do, right?) is messed up because the longitudinal temperature gradient is messed up. This causes the giant circles of fast air known as the jet streams to bunch up and form enormous semi-stable loops known as quais-resonant Rossby waves. Once these suckers are happening, all kinds of things happen, like very wet rainy periods causing major flooding, much larger and more intense than usual blizzards, multi-year droughts, and these very annoying arctic incursions.
And that’s what we are having right now in the upper middle part of North America.
Note that when you get down that far, the difference between F and C matters little.