PMEL Arctic site – Polar Vortex – Jan 6, 2014

Colder temperatures to the north and warmer temperatures to the south create winds that generally blow from west to east around the northern hemisphere. This atmospheric river of strong winds can vary from a straight west-to-east pattern, to a more wavy pattern. With the wavy pattern, cold air from the north can be carried south.

via PMEL Arctic site – Polar Vortex – Jan 6, 2014.