The polar vortex is a permanent broad area of low pressure in the upper atmosphere near the poles. It is located a few miles above the surface of the earth and can be as large as the US and Canada combined. The polar vortex is not new, it is not a storm and doesn’t “hit,” but does influence our weather.
In the winter, it gets colder at the north pole, creating a strong temperature difference between the north pole region and the mid-latitudes. That temperature difference strengthens the vortex that spins around the pole.
A strong polar vortex often means warmer weather for us. That’s because the cold typically stays locked near the north pole due to a stronger jet stream/westerlies that create a barrier between us and the cold arctic air to our north.
When the vortex weakens, the upper atmosphere warms near the poles and the vortex sometimes “splits” and a chunks of the cold air moves south. As the polar jetstream becomes more “wavy” due to a weaker polar vortex, cold air can dip further south.
So don’t expect to go outside and see a polar vortex heading for your house, but you will likely feel the effects of it as we do every winter. Stay toasty my friends.