Sonoma County forecast is for big rains this weekend

Tuesday’s storm dumped as much as 3 inches of rain in higher areas of Sonoma County, and the latest forecast for the coming weekend shows double that amount is possible from the second system arriving this weekend.

The storm brought more than 2 inches of rain to Santa Rosa, flooding the usual low spots and roadways and trapping a handful of drivers who ignored warnings. The rainfall triggered some minor traffic issues, outages and falling trees, but no major damage.

Impressive rainfall amounts throughout the county included 2.27 inches at the Charles M. Schulz-Sonoma County Airport. In the hills west of Healdsburg, more than 6 inches fell since Monday, with most of it coming Tuesday night, said Roger Gass, a meteorologist with the National Weather Service.

Residents recording rainfall for the weather service also reported 3.03 inches in Healdsburg, 3.25 inches in Cazadero, 1.93 inches in Windsor and 1.28 inches in Sonoma.

A few showers could linger Wednesday. Thursday and Friday until nightfall were expected to be dry, but a second storm is likely to drench the region this weekend with possibly twice the amount of rainfall, said Gass.

“It’s definitely looking like a very, very potent storm system,” he said.

The latest forecast calls for Santa Rosa to receive 4.28 inches between Saturday and Monday, with Cloverdale getting nearly 5 inches and coastal mountains approaching 8 inches.

The latest river forecast predicted the Russian River would pass flood monitoring stage of 29 feet at Guerneville around midnight Sunday, and reach 29.7 feet around 4 a.m. Flood stage is 32 feet.

The Navarro River, which runs from near Boonville to the Mendocino County coast near Albion, is forecast to pass its 23-foot flood stage Sunday afternoon, cresting at 27.3 feet around 8 p.m.

The coldest day of the week looks to be Friday, starting out below freezing with some temperatures predicted to be in the upper 20s, Gass said. The air should warm with the arrival of Friday night’s storm.

As of early Wednesday, Santa Rosa has had 20.76 inches of rain since July 1, which is almost 140 percent of normal for this time in the rain year.

Most cities offer free sandbag filling stations at their corporation yards. Some businesses also offer free sandbag filling during storm events, including Friedman Brothers, which has stores in Santa Rosa, Sonoma and Petaluma, and the Soiland Company, which operates Stony Point Rock Quarry in Cotati, Grab N’ Grow in Santa Rosa, and Soils Plus in Sonoma.

Despite the heavy rain and strong winds, Tuesday’s storm caused few major problems, according to several fire chiefs, CHP and other emergency responders.

“We were expecting a lot more issues,” said Graton Fire Chief Bill Bullard.

Graton, which received about 2 1/2 inches of rain in 24 hours, has several trouble areas when rainfall is heavy, particularly the “S” curves on Green Valley Road near Sullivan Road. But as of late morning firefighters had gotten only one call involving a trapped driver, a woman who tried to drive her Honda Civic through the flooded curves. She was able to get out on her own, Bullard said.

The chief estimated there was 3 feet of water atop the rural road. Another closed Graton route was downtown on Graton Road near Ross Road. The swollen Atascadero Creek spread about 10 inches of water over the roadway.

The real issues will come this weekend if the rainfall predictions hold, because the area already is saturated, Bullard said. “There will be nowhere for this water to go. We’ll be gearing up.”

Other problems in the county Wednesday included the low-lying intersection of Highway 12 and 121 in Schellville, which was covered with water, forcing drivers to take a short detour, said CHP Officer Marc Renspurger.

In Valley Ford along Highway 1, firefighters reportedly rescued a few people from their vehicles when they couldn’t make it through the floodwaters over the highway, according to dispatch reports.

“Stay out of the flooded areas. If you can’t see the ground through the water, it’s too deep,” said CHP Officer Steve Fricke.

The storm’s largest power failure outage involved 3,900 customers in Guerneville and west Santa Rosa. Those connections all were restored Wednesday morning, utility spokeswoman Deanna Contreras said. By mid-morning about 50 customers remained out of power throughout Sonoma County and 17 were out in Lake County’s Cobb community.