A bomb cyclone and an atmospheric river will combine with dangerous effect on the West Coast
CNNCNN — A powerful “bomb cyclone” will combine with an atmospheric river to unleash over a month’s worth of rain, hurricane-force wind gusts and feet of mountain snow to parts of the Pacific Northwest and Northern California. A storm system off the Pacific Northwest is expected to rapidly intensify on Tuesday in a phenomenon called “bombogenesis” and earn it the moniker of “bomb cyclone.” It will intensify so much so quickly that it could become a “triple-bomb,” tripling the criteria needed to be considered a bomb cyclone, the National Weather Service in San Francisco said. This bomb cyclone will work with an atmospheric river, a long plume of water vapor moving like a river through the atmosphere, to wring out heavy rainfall and significant mountain snowfall in the Pacific Northwest and Northern California beginning Tuesday. A level 2 of 4 threat of flooding rainfall is in effect for parts of northwestern California and southwestern Oregon where 2 to 5 inches of rain could fall, the Weather Prediction Center said.