A ‘bomb cyclone’ is set to bring more heavy rain to California. The “truly … brutal system … that needs to be taken seriously,” per the National Weather Service, could dump as much as four inches of rain on San Francisco and up to eight inches of rain at higher elevations. The storm poses especially hazardous flood dangers because it so closely follows last week’s atmospheric river.

“Everything is now completely saturated,” UCLA climate scientists Daniel Swain said during a YouTube briefing. Climate change, mainly caused by the extraction and combustion of fossil fuels, increases the likelihood of extreme atmospheric river events. “The dominant thing that’s happening is just that, in a warmer atmosphere, there’s exponentially more potential for it to hold water vapor,” said Daniel L. Swain, a climate scientist at the University of California, Los Angeles. “And that exerts a really profound influence on things.”

Gusts as high as 70 mph are also expected. “To put it simply, this will likely be one of the most impactful systems on a widespread scale that this meteorologist has seen in a long while,” a National Weather Service Bay Area forecaster wrote in a Jan. 2 area forecast discussion. (Washington Post $, San Francisco Chronicle, Axios, San Francisco Chronicle; Climate effects: New York Times $; Climate Signals background: Extreme precipitation increase)