Tens of thousands of homes in Washington state lost power Tuesday and downed wires or trees locked some highways as Northern California and the Pacific Northwest started feeling the effects of a powerful atmospheric river event,

A series of storms fueled by a strong atmospheric river is taking aim at the Bay Area and Northern California, intensified by a so-called "bomb cyclone" that promises heavy rain and potential flooding.

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.