The West Coast is preparing for a long-duration heavy rain event from a bomb cyclone set to form Tuesday.Threat level: The rapidly intensifying storm, taking shape in the northeastern Pacific Ocean, is forecast to direct a strong atmospheric river at southwestern Oregon and Northern California for days on end.

A powerful winter storm brewing near the Pacific Northwest known as a bomb cyclone is dragging an atmospheric river.

A powerful storm is bearing down on the West Coast and bringing with it a scary-sounding weather term - bomb cyclone. Bomb cyclone is a term used by weather enthusiasts to describe a process that meteorologists usually call bombogenesis.

A huge storm is predicted to hit Washington, Oregon, and California this week linked to atmospheric river weather systems.