North Coast, Bay Area to get soaked in upcoming rainstorms

Hold fast to your memories of last month's sunshine and warm, springlike weather. There's a doozy of a storm coming in, and it's bringing lots of rain.

In what meteorologists say could be the onset of a persistent wet weather pattern for March, forecasters are calling for a potent weekend storm they expect will dump up to 7 inches of rainfall in the wettest coastal areas by Monday.

Even low- lying urban areas around the North Coast and Bay Area can anticipate upward of 2, 3, even 4 inches of rain between Friday and Monday afternoon, with the heaviest rainfall lasting all day Saturday amid increasingly powerful winds, forecasters said.

“It's going to be wet,” said Monterey-based National Weather Service meteorologist Diana Henderson. “It's a Netflix kind of day - as long as the power holds out.”

This is a significant storm - what is known in some quarters as an “atmospheric river” - which, in addition to heavy downpours, is predicted to bring gusting winds as high as 50 mph by Saturday evening, raising the possibility of downed trees and surface flooding through the weekend.

After four years of drought, the winter started out wet, only to turn dry in February. Rainfall totals around Santa Rosa are at about 73 percent of normal, so more rain is welcome.

“We're a little shy so far,” Henderson said. “Hopefully, by the end of the weekend, we'll be a lot closer.”

The weekend system is expected to deliver plenty of rain into local reservoirs, enough that the U.S. Army Corps of Engineers made minor releases this week to make room in Lake Mendocino.

Lake Mendocino, currently at about 71 percent of flood capacity, could get up to 5 inches of rain over the weekend, meteorologist Shawn Palmquist said from the weather service's Eureka office.

Another major rain storm is expected around Thursday.

There's still plenty of space in both Lake Mendocino and Lake Sonoma, which fills more slowly and on Thursday held about 62 percent of total capacity.

After recent talk about a stalled El Niño, “I think El No-Show is about to turn into El Go-Show,” quipped research meteorologist Marty Ralph, who works closely with the Sonoma County Water Agency, earlier this week.

Sonoma County officials on Thursday invoked a Code Blue, expanding homeless shelter capacity and warming centers because of the change in weather conditions. The Code Blue will be in effect until at least Tuesday.

“It definitely looks like an active weather pattern at least through the end of this week,” Palmquist said. “And, at this point, it looks like into the middle of next week.”

You can reach Staff Writer Mary Callahan at 521-5249 or mary.callahan@pressdemocrat.com. On Twitter @MaryCallahanB.