Will the Bay Area’s Dry Winter Flip? Not Just Yet, But Storms Could Be Coming

After weeks without rain, the Bay Area could see a bit this week. No need to pull out the rain gear too quickly, though — the weather system isn’t expected to end the region’s dry spell just yet.

Only light showers are expected through the northern and coastal Bay Area from Tuesday night into Wednesday morning, according to National Weather Service meteorologist Dalton Behringer. But, he said, it could be a foreshadowing of a more stormy February to come.

“We do have some hints of some storms coming up for the start of next month,” he said. “Pretty much starting the First of February, there’s a chance for rain.”

This week’s showers, which are expected to roll through the North Bay beginning Tuesday evening, could produce measurable rainfall in Sonoma County and down the coast of the Bay Area, through San Francisco and the Peninsula. The rest of the region will likely remain dry after the storm system shifted slightly north, toward Humboldt and Mendocino.

The last few weeks of dry, if chilly, weather have been a welcome reprieve for many in the Bay Area, after a wave of heavy rains in December and early January dumped record rainfall and led to widespread flooding and power disruptions.

The month of steady storms made up for a slow start to the water year, delivering more than 6 feet of snow to the Sierra, where ski resorts had delayed openings for weeks. The region’s snowpack jumped 600% in the last week of December, bringing Northern California’s levels to about 75% of the annual norm.

That’s dropped to about 40% in the last few weeks of dry weather, according to California Department of Water Resources’ snow surveys.

Throughout the stop-and-start, the Bay Area’s rainfall totals have also leveled out. San Francisco is at 96% of its annual average, while Petaluma in Sonoma County is around 85%, according to National Weather Service data.

Still, Behringer said, “as long as we don’t stay dry for too long, we are still okay.”

“It can be kind of typical for us to have a midseason lull,” he said. “It’s hard to say how much longer it’s going to last. There’s still a good chance we could pick up for the rest of the season.”

He said there’s still a good amount of uncertainty regarding any storms on the forecast so far out, but rain is expected over the weekend, and again beginning Feb. 8.

Behringer said weeks of dry weather can raise fire risk, since some of the lighter fuels like brush and grass have started to dry out. But in terms of water supply, most of California’s reservoirs remain unseasonably high: Santa Barbara County’s Cachuma reservoir is at 150% of its historic average as of Sunday, and Shasta Lake, the state’s largest reservoir, is at 125%.