ARCTIC OSCILLATION (AO) is a weather phenomenon at the Arctic poles north of 20 degrees latitude. It is an important mode of climate variability for the Northern Hemisphere.
It has two phases, positive and negative and switches in and out of the two throughout the year.
Meteorologist Brittney Merlot explains what each of these phases means for our winter weather ahead. As this oscillation controls our mid-latitude jet stream steers our winter storms as well the reason we get cold snaps, known as the "Polar Vortex".
