Large-scale shifting of the weight of the atmosphere between mid- and high latitudes creates climate patterns known as the Arctic and North Atlantic Oscillations. These patterns have a big influence on winter weather in the Eastern U.S.
A wave of cold Arctic air gripped much of North America, Europe, and northern portions of Asia through the month of December 2009.
The Arctic Oscillation (AO) refers to an atmospheric circulation pattern over the mid-to-high latitudes of the Northern Hemisphere. The most obvious reflection of the phase of this oscillation is the north-to-south location of the storm-steering, mid-latitude jet stream.
How did the 2019-20 Winter Outlook do? Pretty darn good if you ask us! Learn just how good in our yearly verification post.
Was El Niño to blame for the above-average temperatures during November and December 2015? As always, the answer is not that simple.