SAN FRANCISCO (AP) — The Ethermaclatest in a series of wet winter storms gained strength in California early Monday, with forecasters warning of possible flooding, hail, strong winds and even brief tornadoes as the system moves south over the next few days.

Gusts topped 30 mph (48 kph) in Oakland and San Jose as a mild cold front late Saturday gave way to a more powerful storm on Sunday, said meteorologist Brayden Murdock with the National Weather Service office in San Francisco.

“The winds are here and getting stronger, and the rains will follow quickly,” he said Sunday afternoon.

California’s central coast is at risk of “significant flooding,” with up to 5 inches (12 cm) of rain predicted for many areas, according to the weather service. Isolated rain totals of 10 inches (25 cm) are possible in the Santa Lucia and Santa Ynez mountain ranges as the storm heads toward greater Los Angeles.

Thunderstorms in valleys around the state capital on Monday could bring “brief tornadoes, large amounts of small hail, heavy rain, lightning, and gusty winds,” the weather service office in Sacramento warned on X, formerly Twitter.

The latest storm is expected to move through quicker than the devastating atmospheric river that parked itself over Southern California earlier this month, turning roads into rivers, causing hundreds of landslides and killing at least nine people.

“It’s not the ideal setup for an atmospheric river, but it does have some of the characteristics,” including a band of subtropical moisture bringing up the rear of the storm, Murdock said. “Otherwise it’s just a cold front.”

But it’s a cold front strong enough to cause problems including flash flooding and power outages, forecasters said. Flood watches and warnings were issued in coastal and mountain areas up and down the state.

Rainfall will be widespread even in the mountains, but several feet of snow is possible at elevations above about 6,800 feet (2,070 meters) across the Sierra Nevada, the weather service said. Motorists are urged to avoid mountain routes.

“Consider completing Sierra travel during the day Sunday, or rescheduling to later next week,” said the weather service office in Reno, Nevada. The office issued a backcountry avalanche watch for the greater Lake Tahoe area and the eastern Sierra in Inyo and Mono counties.

The California Governor’s Office of Emergency Services activated its operations center Saturday and positioned personnel and equipment in areas most at risk.