With the wettest storm of the season expected to roll into the Bay Area on Wednesday, residents in sections of the North Bay ravaged by October wildfires are being warned of buckling roads, landslides, sinkholes and possible evacuations.
The bulk of the rain will fall across the region from Wednesday afternoon to Thursday morning, said Ryan Walbrun, a meteorologist with the National Weather Service.
By 3 p.m. on Wednesday, the North Bay is expected to be drenched — with up to an inch forecast for the valleys and as much as three inches expected in the hills, Walbrun added.
“That’s of concern, of course, just for the fire scars and the debris out there,” Walbrun said. “After the fires, the soils can’t handle too much moisture.”
In October, wildfires driven by gusts of up to 80 mph spread in six counties (Napa, Solano, Sonoma, Lake, Mendocino and Yuba), killing 43 people, destroying nearly 9,000 structures and burning more than 150,000 acres.
In Santa Rosa, particularly in the Fountaingrove neighborhood, officials are monitoring the risks the storm could pose. New evacuations are possible, said Santa Rosa Mayor Chris Coursey.
“We want our residents to be prepared and alert as this situation unfolds,” Coursey said at a Sunday news conference.
So far, at least eight sites where water pipes were destroyed because of the fires have been identified, increasing the risk of landslides, sinkholes and flooding, said Ben Horenstein, the director of the Santa Rosa Water Department.
Workers went to 1,200 homes in the areas of the ruined infrastructure to let residents know of the risks that the damaged storm water drains could pose.
Twenty-two other water pipe locations have been identified with possible damage that could threaten homes.
“The city will have crews in the field during the upcoming storm events to monitor the situation,” Horenstein said.
So far, no evacuations have been ordered for the North Bay, but Santa Rosa Deputy Fire Chief Bill Shubin asked residents to be vigilant.
Elsewhere in the Bay Area, the storm is expected to bring about three-quarters of an inch of rain to San Francisco and Oakland, Walbrun said.
Temperatures won’t drop dramatically during the storm, Walbrun said, adding that the daytime forecast for most of the Bay Area will be in the 60s.
“It’s a pretty warm rain,” Walbrun said. “It’s not a cold front. The rain is the big deal. It’s still early mid-November, it’s not unusual for us to get rainstorms.”
The storm is expected to dry out quickly by Thursday, Walbrun said.
“The big concern would be the burn scar areas and any impacts up there,” Walbrun said. “So just urge the public to listen to the officials up there as they deal with the cleanup.”
Sarah Ravani is a San Francisco Chronicle staff writer. Email: firstname.lastname@example.org Twitter: @SarRavani