A couple of winters ago, the term, “Polar Vortex” became a media buzzword used and abused by many people with no idea of what they were talking and writing about. The Polar Vortex is actually a large low pressure system thousands of feet high in the atmosphere over the North and South Poles. When the northern Polar Vortex is strong and circular, as it has been this winter, the coldest air in the hemisphere remains over the North Pole. When the Polar Vortex weakens and becomes more irregularly shaped, lobes of colder air tend to drop equatorward while the high Arctic areas get mild spells of weather. This winter, the Polar Vortex has been almost perfectly circular and quite strong so there have been no real outbreaks of Arctic air into the mid-latitudes anywhere.
