Polar Vortex

NASA

Snow Buries Kamchatka

It has been an eventful few months for the Northern Hemisphere atmosphere. An unusually early sudden stratospheric warming episode in late November appears to have factored into a weakened and distorted polar vortex at times in December, likely causing extra waviness in the polar jet stream. This helped fuel extensive intrusions of frigid air into the mid-latitudes, contributing to cold snaps in North America, Europe, and Asia, and…