The effects of a rapidly developing bomb cyclone slammed the Seattle area on Tuesday night, killing at least two people and knocking out power to hundreds of thousands of utility customers as ferocious winds toppled trees and power lines across western Washington.

Two people were killed near Seattle and more than a half-million homes and businesses were left in the dark Wednesday in the wake of back-to-back storms that battered the Pacific Northwest.

A bomb cyclone and an atmospheric river will continue lashing the Pacific Northwest with severe weather conditions, the National Weather Service said.