A once-in-a-decade bomb cyclone is taking shape off the West Coast [View all]

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.

Bomb cyclones are formidable and unload heavy snow and strong winds during the winter. This one could be among the most intense on record for its location, a storm that occurs only “about once every ten years,” and will generate “some of the strongest winds we have seen in several years” that churn up “very dangerous mountainous seas of 30 to 35 feet,” the National Weather Service in Medford, Oregon, 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. The pair will stall along the coast and hammer the area with hazardous conditions through the week and into the weekend.

https://www.yahoo.com/news/bomb-cyclone-atmospheric-river-combine-154819751.html