A powerful atmospheric river is expected to strike northern California and the Pacific Northwest on Tuesday evening, bringing damaging winds, up to 15 inches of rain and heavy snow in the mountains. The National Weather Service said wind gusts of 60 to 70 mph are expected along the coastlines of northern California,

Beyond wind, rain and snow, the storm could also bring flash flooding, rock slides and debris flows as well as heavy mountain snow and blizzard conditions in areas of high elevation. The "bomb cyclone" - as forecasters call it - is caused by air pressure quickly dropping off the coast, which has rapidly intensified the weather system.

Northern California and the Pacific Northwest residents on Tuesday were bracing for the strongest atmospheric river storm system, bringing a lot of rain to some areas and creating the potential for a “bomb cyclone” that can intensify wind overnight.