Get out your umbrellas: A series of storms is on the way. Here’s when and how much rain they will bring to the Bay Area

It’s not quite the deep snow of Buffalo, the subzero temperatures of Iowa, or the freezing rain of Portland. But after a relatively dry start this year, winter conditions in the Bay Area will kick into gear in earnest this weekend, forecasters said Tuesday, with rain, strong winds, downed branches and clogged storm drains likely — just in time for the 49ers home playoff game.

“This will be one of the more notable rain events so far this winter,” said Dial Hoang, a meteorologist with the National Weather Service in Monterey. A series of at least two, and maybe three storms from a strengthening jet stream is expected to begin Friday morning, and continue off and on Saturday, Sunday and Monday, dumping 2 to 3 inches of rain across most Bay Area cities, with 4 inches or more possible in the Santa Cruz Mountains, Big Sur and the North Bay Hills.

Some outlier areas in the hills could see as much as 8 inches over the weekend, Hoang said. The Bay Area will see the most rain since Dec. 17 20, when 3.08 inches fell on San Francisco. “This will be the biggest 4 day stretch of rainfall of the winter so far, or close to it,” said Jan Null, a meteorologist with Golden Gate Weather Services in Half Moon Bay.

A year ago, strong atmospheric river storms pounded California, causing serious flooding along the coast and in the Central Valley. Those storms, combined with another wave of storms in March, ended the state’s three year drought, dumped the biggest snowpack on the Sierra in 40 years, and caused significant damage to waterfront restaurants in Capitola and destroyed part of the Capitola Wharf.

This weekend’s storms might end up being an atmospheric river — a powerful stream of moisture coming from the tropics. But forecasters say even if they hit that level, they will deliver modest atmospheric river conditions “This is going to be a series of beneficial rain storms,” Null said. “These aren’t big events like last year with major flooding.” More details will emerge as Friday draws closer, experts said Tuesday.

What will it mean for fans heading to Levi’s Stadium on Saturday afternoon for the NFL playoff game between the favored 49ers and the underdog Green Bay Packers? “Be prepared for some rain,” Null said. “The exact timing is hard to nail down now. Fans might luck out and be in the window between storms.

It doesn’t look like a downpour. The fans will probably have better luck than the Packers.” So far, most cities in California are below historical rainfall averages for this time of year. But with decent rains over the past two weeks, the totals have been creeping up. And this weekend’s storms should give a big boost to those numbers.

The storms also are expected to help build up the Sierra Nevada snowpack, the source of one third of California’s water supply. Two weeks ago, the statewide Sierra snowpack was just 25% of its historic average after a warm, dry December. On Tuesday, after several solid storms, it had jumped to 49% of normal for mid January.

This weekend’s storms are expected to bring about 1 foot in the Lake Tahoe area, and as much as 3 to 4 feet farther south at places like Ebbett’s Pass, Carson Pass, and the high country of Yosemite National Park, according to the National Weather Service in Sacramento. But rather than the cold storms we’ve been getting, the new storms are expected to be warm — riding the jet stream from Hawaii toward California.

That means the snow level will be at least 6,500 feet or higher, Null said. What does it all mean for the summer water supply? Too soon to tell, since there are still three more months of winter left. If the current pattern continues — occasional good storms broken up by multiple days of dry weather — that will allow reservoirs already at above average levels from last year’s deluges to top up in an orderly way.

If there are long dry spells, that will result in a drier than normal winter, but one that likely won’t lead to major water restrictions this summer, water managers say, since the reservoirs already are in good shape. The worst outcome? Multiple big atmospheric river storms that quickly fill the rest of the capacity in reservoirs, causing flooding.

Nobody knows which of the outcomes will unfold between now and April. “California saw firsthand last year how historic drought conditions can quickly give way to unprecedented, dangerous flooding,” said Karla Nemeth, director of the state Department of Water Resources, earlier this month..