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 "bomb cyclone" is forecast to bring heavy snow, high winds and life-threatening flooding to the Pacific Northwest in the next few days.

Though that type of weather system doesn’t often develop near Washington, the last one that impacted the Pacific Northwest was earlier this year in January. Bomb cyclones are weather systems that form when the storm’s central pressure drops more than 24 millibars in 24 hours.