I would say north of San Francisco on up to Oregon will probably see the worst parts of it.
Northern California saw heavy rain that swelled rivers and caused flooding in low-lying areas over the weekend.
Flash flood warnings were issued for Napa, Sonoma and Marin counties as a series of storms moved through the region. St. Helena received heavy rain.
Some coastal mountain areas saw as much as nine inches of rain in 24 hours.
Near Ferndale, the weather service reported a rare tornado that started as a waterspout in the Pacific and moved onshore. No damage was reported there.
But winds in Napa County downed trees and power lines, according to a fire department dispatcher there.
Wind gusts at the Golden Gate Bridge were clocked at 63 mph, and the San Francisco Airport saw weather-related delays. More than 100,000 people in the Bay Area experienced power outages.
In San Francisco, the wind knocked over some scaffolding, injuring one person.
"We've got our crews out there. They're working hard and we're going to try to get these folks restored as soon as we can," said PG& E spokesperson John Tremayne.
"I would say north of San Francisco on up to Oregon will probably see the worst parts of it," added Diana Henderson of the National Weather Service.
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