Polar Vortex

Polar vortex sunrise this morning.  -3F here, halfway between the equator and the North Pole.

This winter weather phenomena is not anything new.  Rather, the term polar vortex has been popularized in recent years bringing attention to weather that has always been there. While we feel the effects on the ground the action is taking place tens of thousands of feet higher in the upper atmosphere.

There is a large area of low pressure and frigid air that persists at both the earth's poles.  It is the counter-clockwise motion of this flow of air that lends its name to vortex.  It is always there and strengthens in the winter while weakening during the summer months. Periodically during winter this air mass will expand, sending cold air southward via the jet stream.  Not confined to North America these cold surges occur in Europe and Asia as well.

While wild critters are better adapted to extremes of weather the only danger to people and their families is prolonged exposure to extremes of cold.  Which is why you should find a spot to bask in the winter sunshine.