You have probably heard the term polar vortex before, but what exactly is it, and how did it contribute to the freezing temperatures we experienced in mid-January?
The polar vortex, an area of low pressure and cold temperatures around the earth’s polar regions, always exists. It strengthens in winter and weakens during the summer.
Many times, just like in mid-January, parts of the polar vortex expand sending cold air south into the United States. This is a common occurrence during the winter months and is often why we see cold air outbreaks across large portions of the country.
Under normal atmospheric conditions, the polar vortex and accompanying polar jet stream remain well north of our area. This keeps the Arctic air locked up in the Arctic region.
When there are disturbances in the jet stream pattern, like the cold in mid-January, the polar jet stream is pushed further south, and part of the polar vortex is shoved with it. Resulting in below-average temperatures across much of the county.