The low pressure center located near the Aleutian Islands on mean charts of sea level pressure during the winter. It represents one of the main centers of action in the atmospheric circulation of the Northern Hemisphere.

A semi-permanent, subpolar area of low pressure located in the Gulf of Alaska near the Aleutian Islands. It is a generating area for storms and migratory lows often reach maximum intensity in this area. It is most active during the late fall to late spring. During the summer, it is weaker, retreating towards the North Pole and becoming almost nonexistent. During this time, the North Pacific High pressure system dominates.