A massive storm developing in the Pacific Ocean is expected to hit Northern California on Wednesday.
The National Weather Service in San Francisco has issued a flood warning for between Wednesday morning and Thursday afternoon.
The NWS expects widespread flooding, land- and mudslides, impassable roads, and rapid rises in rivers and creeks.
“The impacts will include widespread flooding, roads washing out, hillside collapsing, trees down (potentially full groves), widespread power outages, immediate disruption to commerce, and the worst of all, likely loss of human life,” the NWS said in a statement. “This is truly a brutal system that we are looking at and needs to be taken seriously.”
The NWS also said it expects between 2-4 inches of rain in valleys, 3-6 in hills, and 8-10 in coastal mountain areas.
This is coming off the heels of another storm that left 50,000 people without power on Monday in California.
That type of storm is called an atmospheric river — thousands of miles of concentrated water vapor which extend from the tropics to the western United States, often originating near Hawaii. Monday’s atmospheric river event dropped 5 inches of rain in San Francisco and 10 inches in other parts of the state.
The storm expected to make landfall Wednesday is another atmospheric river event. The storm could reach as far south as Los Angeles and farther north than San Francisco.
Daniel Swain, a climate scientist at the University of California, Los Angeles, told reporters at a news conference Tuesday that the storm could result in mudslides, but is unlikely to cause river flooding.
“The big wildcard is what happens next week,” Swain said. Two more atmospheric river events are predicted to hit the California coast at that time. “Then all bets are off and the potential for much more significant flooding could very realistically emerge.”