What is the Polar Vortex?

Image courtesy: National Weather Service

(WWLP) - With such extreme cold temperatures across much of the country, there has been a lot of talk about the ' polar vortex ' lately. While some have compared the polar vortex to an 'arctic hurricane,' there is no such thing, and the vortex is not even a storm at all.

Here is what the National Weather Service has to say about it:

The polar vortex is a persistent ring of winds over the poles in the upper levels of the atmosphere. It ALWAYS exists at the poles, but weakens during the summer and strengthens in the winter. Many times in the winter, a piece of the vortex breaks off and is sent southward with the Jet Stream, which is what is happening right now.

The polar vortex is:

NOT something new. NOT something that exists on the Earth's surface; it is in the upper atmosphere. NOT something that will be visibly observed like a hurricane, tornado, funnel cloud, thunderstorm, etc. NOT something (in itself) dangerous to humans, but the arctic air associated with them at the surface could be.