Get your umbrellas back out because California’s wet winter isn’t over yet. A moisture-rich atmospheric river that is bearing down on Northern California is expected to dump up to 8 inches of rain on portions of the Bay Area, unleash gusty winds and bring the potential for widespread flooding through at least Thursday. The storm, bringing warm air from the tropics into the region, is expected to raise snow levels to 6,000 feet across much of the Sierra Nevada, said Hannah Chandler-Cooley, a meteorologist with the National Weather Service in Sacramento.