Pineapple Express

A Pineapple Express is a specific type of atmospheric river that occurs in the waters northeast of the Hawaiian Islands and affects locations along the Pacific coast of North America, characterized by a strong and persistent flow of warm moist air and associated heavy precipitation. The phenomenon is driven by a strong southern branch of the polar jet stream and a surface frontal boundary, often created by the Madden-Julian oscillation or an El Niño episode, resulting in torrential rains, heavy snowfall in the mountains, and rapid snow melt due to warming.learn more on wikipedia