A major storm was sweeping across the northwest U.S., battering the region with strong winds and rain and causing widespread power outages and downed trees that killed at least one person.

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

The Weather Prediction Center issued excessive rainfall risks beginning Tuesday and lasting through Friday as the strongest atmospheric river — a large plume of moisture — that California and the Pacific Northwest has seen this season bears down on the region.

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

Northern California and the Pacific Northwest are bracing for what is expected to be the strongest storm of the season so far, with heavy rain and winds set to pummel the region and potentially cause power outages and flash floods.

As an atmospheric river is expected to bring heavy rain and mountain snow to California, many are turning to Google to search the term "bomb cyclone." But what is that? In short, it's a rapidly intensifying storm system.