The cold snap headed our way this weekend is not The Polar Vortex.
The Polar Vortex is a feature of the upper levels of the atmosphere. It is a high-level wind current that circulates around the polar region. During winter, when this circulation is strong and nearly circular, the polar region is very cold and our weather tends to be average or warmer than average. When the Polar Vortex is weak, there is much more exchange of air between the mid-latitudes and the pole.
At certain times, big blobs of warmer air move northward and displace polar air southward. This leads to cold weather outbreaks deep into Europe, Asia, and here in the United States. But to confuse this weekend’s cold snap with The Polar Vortex is like referring to the Russian dance in The Nutcracker as The Russian Revolution.
Meteorologist John Wheeler