Bay Area weather timeline: Rainy holiday projected through Christmas week

OAKLAND, Calif. - The Bay Area’s dry December is coming to an end. New weather forecasts show that moderate to heavy rains will hit the region this weekend and could continue through the New Year.

The NWS projects that the two storm systems moving through the region, which are expected to last through Saturday, will together bring less than 1.5 inches of rain.

Rain forecast

Expert perspective:

However, a third and more serious storm front is projected to arrive hot on their heels. Some forecasts show the storm could bring as much as 5 inches of rain.

"(On) Sunday, we’re talking about the potential for isolated thunderstorm activity, as well as high winds," KTVU weather forecaster Devin Trubey said. "Once we start our system on Sunday, it’s just a conveyor belt of moisture, and it continues. We’ll be having rain through Tuesday, most likely into Christmas Eve and parts of Christmas Day."

December is usually a wet month for the region, but in 2025 the month has been mostly dry. However, the upcoming storms are expected to put the region on track for a typical year’s amount of rain.

"In my decades of forecasting weather, I’ve never seen anything so complex. Today I spoke to three different meteorologists and all three had different opinions," KTVU’s Roberta Gonzalez said. "That shows you how complex the timing of the system is, not so much the amount of rain. We'll know by Monday if our coastal areas will start to see the risk of rock slides and coastal flooding."

Gonzalez says around the immediate Bay Area, there will be potential for urban and small street flood advisories, and also wind into Sunday afternoon and evening.

Bay Area weather timeline

• Wednesday, Dec. 17: Dry evening
• Thursday, Dec. 18: Dry conditions
• Friday, Dec. 19: Rain develops
• Saturday, Dec. 20: Small breaks in the rain with a large storm system arriving later in the day
• Sunday, Dec. 21: Potential thunderstorms and high winds
• Monday, Dec. 22: Rain
• Tuesday, Dec. 23: Rain

Bay Area residents making preparations

Across the Bay Area, preps are under way for the deluge of rain. 

"Someone said atmospheric river and that's that's got me on alert," said James Leeper of Oakland. 

What you can do:

In San Jose's Alviso neighborhood--which is several feet below sea level--sandbags are the hot commodity. Santa Clara County residents can pick them up at stations across the county on Thursday and beyond. 

Sandbags are available at the locations listed here. 

Meanwhile, in a social media post Wednesday, the City of Oakland urged its residents to "stock up on sandbags and clear storm drains." 

For Leeper, it was a lesson learned during the last heavy rain. 

"The water came in the driveway, down the house, down this side, and took a lot of dirt and stuff with it," said Leeper. 

This time around, he's taking no chances--with sandbags strategically placed around his property. 

"I am ready this time, yes I am," said Leeper. 

Oaklanders can pick up free sandbags at the Municipal Services Center on Edgewater Drive, or the Drainage Services Facility on Shepherd Canyon Road. For more details on pickup times and other storm preparation tips, click here. 

CHP urges holiday drivers to use caution

There's no question the Bay Area needs rain, but what it may not need is so much rain, all at once.

What they're saying:

"Obviously, we lead into the Christmas holiday week, we're going to see more people traveling and we're going to see a lot water," said Sgt. Andrew Barclay of the California Highway Patrol's Golden Gate Division. 

Barclay says extra officers will be on duty area-wide, due to the holiday enforcement period. 

"I think that stepped-up patrol kind of coinciding with these storms is going to work out very well, having more people out there available to respond to calls to help clear the roads," said Barclay. 

The CHP is cautioning residents to stay home if you can. If you can't, make sure your car is road-ready, allow plenty of time to get to your holiday destination, and watch out for standing water. 

"Do not risk it, do not try to drive through it," said Barlcay.

And with snow and mixed precipitation possible at higher elevations over Christmas, travelers headed to places like Tahoe are urged to keep a close eye on the forecast. 

"Know what's coming. Obviously, if we're getting rain here, very likely we're going to see snow up in the Tahoe area. But number two is check your entire route, check through Caltrans, follow the social media accounts for our CHP offices going all the way up to Truckee," said Barclay.