Storm Spreads Throughout Bay Area; SFO Flights Impacted

Update, 5 p.m.: Wind and rain continues to hammer much of the Bay Area as the workday comes to a close. Google Traffic is showing several incidents snarling traffic on I-80, I-580 and 101 southbound.

A wide-ranging wind advisory is expected to last until 4 a.m. Saturday, with sustained winds of 25 to 40 mph and gusts up to 60 mph possible.

So far rainfall totals are modest, many areas receiving less than an inch. Forecasters say that as much as 10 inches could fall on parts of Sonoma and Napa counties before the storm is over.

24-hour Rainfall totals:

The slower-than-expected start to the storm was a good sign to Healdsburg Public Works Director Brent Salmi, who told The Press Democrat that despite flooding fears, water remained at manageable levels.

“As long as it keeps raining the way it is, there’s probably no issue,” Salmi said. “The rain kind of ebbs and flows, and none of it has been terribly heavy.”

The Russian River was expected to remain well within its banks through Monday. Only the Navarro River in Mendocino County was at risk of overflowing.

Update, 2 p.m.: The leading edge of a windy storm that hit the North Bay this morning has spread throughout the rest of the Bay Area.

A wind advisory remains in effect throughout the region, as well as a flash flood watch in Marin, Napa and Sonoma counties.

Meteorologist Jan Null of Golden Gate Weather Services said we've got a "juicy band of rain" on our hands, even though it's taken awhile to spread south. In the North Bay, rainfall totals are beginning to mount, with Venado, a very rainy hilltop site west of Healdsburg, soaking up more than 5 inches as of 1:30 p.m. In other parts of north Sonoma County, more than 2 inches have collected.

"When we've had a dry period and we're sort of bumping that high pressure out of the way, things tend to go a little slower," Null said. "But now, things seem to be going fairly well."

Winds have been strong at higher elevations -- the heaviest gust was 58 mph in Los Gatos.

As of 12 p.m. in the Bay Area, the power went out at about 24,540 households, and 15,710 of those residences have been restored, PG&E said.

There are also dozens of reports of lightning strikes near Sacramento, and at least one near San Francisco's Ocean Beach.

The National Weather Service expects the afternoon commute to be a wet one.

Crews in Sonoma County have prepared for minor flooding but nothing like the damage from a stronger system back in December.

"The wind is really the one that we worry about in the coastal areas, and especially in the higher regions of the mountainous areas," said Ursula Hanks, coordinator of Marin County's Office of Emergency Services.

Forecasters expect about 2 to 4 inches of rain in urban areas -- much more on the Sonoma coast.

Null said significant river rises would probably occur north of the Bay Area. The Russian River is unlikely to flood, he said, though local creeks and streams will be susceptible.

Meanwhile, weather at San Francisco International Airport is causing flight cancellations and delays, airport officials said. Seventy-seven departures and 78 arrivals have been canceled, said airport duty manager Joe Walsh. He said delays are about 60 to 90 minutes.

The delays are occurring to both inbound and outbound flights, but Walsh said most of the delays are to arrivals. A delay program at the airport went into effect at 9 a.m. today and will be in effect until 10 p.m., Walsh said.

Officials at Oakland International Airport are reporting one canceled flight today because of the weather.

The Marin Independent Journal is live blogging the storm here.

Update, 6:25 a.m. Friday: Our message to that incoming Pacific storm: Hey, we'll put up with a lot, but we expect you to show up on time, man. And you are officially late.

Yes: We bought into all the flash flood watches and the talk of 10 inches of rain out there somewhere in the hills north and south of the bay. Starting up there in Sonoma County by midnight. But as dawn dawns, there's been barely enough water coming out of the sky to wet the bottom of a rain gauge.

So what gives?

Well, if you go far enough north -- close to the Sonoma-Mendocino County line -- it has been raining overnight, though hardly in torrents. Cloverdale, at the northern edge of Sonoma, got .48 of an inch between midnight and 6 a.m.; Venado, a very rainy hilltop site west of Healdsburg, also in Sonoma County, has gotten .64, and Santa Rosa .05. Closer to the central Bay Area, several Marin locations, including the village of Olema near Point Reyes, have reported .01 of an inch since midnight.

Much farther up the coast -- in northern Mendocino and Humboldt counties -- there's been lots of rain. Honeydew, a hamlet on the Mattole River in southern Humboldt, has gotten about 7 inches of ran in the past 24 hours.

For the Bay Area, the National Weather Service is now saying we should expect rain in the central Bay Area by this afternoon. A flash flood watch for North Bay counties, originally set to expire at 10 p.m. Friday, has been extended to 6 a.m. Saturday.

An advisory for winds between 25-35 mph with gusts up to 60 on peaks and ridgetops is in place through 4 a.m. Saturday. Highest wind gusts reported so far have been 56 mph on Mount Diablo and 49 mph at Point Reyes. Caltrans has posted a high-wind advisory for drivers on the Bay Bridge throughout the day Friday.

Earlier post: Watching the National Weather Service online radarscope Thursday night after six weeks of midwinter dry weather, you can see there's rain out there offshore. But it has seemed to crawl toward the coast all evening.

But as of 10:30 p.m. Thursday, we've got the first reports of rain in the nine-county Bay Area: four-hundredths of an inch of rain in the Sonoma County town of Cloverdale, on the border of Mendocino County. The Middle Peak rain gauge on Mount Tamalpais has recorded one-hundredth of an inch.

That's a modest beginning for a pair of storms expected to bring up to 10 inches of rain to the highlands of the North Bay, up to half a foot to the Santa Cruz Mountains, and between an inch and 4 inches of rain to the San Francisco Bay shore and nearby valleys.

The storm is also expected to be a blustery one, with sustained winds of 20 to 35 mph and gusts that could hit 60 mph on Bay Area peaks and ridgetops.

The storm arrives after a history-making January -- the first time no rain was recorded during the first month of the year since record keeping began in the winter of 1849-50.