Pounding storm due Thursday morning

Yet another pounding storm was bearing down on Sonoma County Thursday, packing enough punch to warrant a new round of flash flood watches after Wednesday's steady rain and the wind-whipped Monday-Tuesday deluge. Santa Rosa can expect about 1.5 inches of rain, while the coastal hills could receive 2 to 4 inches.

“There could be some heavy rainfall with this one,” said Anna Schneider, a meteorologist with the National Weather Service.

Unlike Monday night's storm, which pummeled the region as people slept, Thursday's wet weather will play out mostly in daylight and last a shorter period of time.

The National Weather Service on Wednesday morning issued more flash flood warnings for all North Bay counties from 4 a.m. Thursday through Thursday evening.

“Things will go downhill in a hurry due to the state of the creeks and the river,” said Ryan Walbrun, a National Weather Service meteorologist.

A wind advisory also was issued for expected strong gusts up to 50 mph.

Showers could continue into Friday, followed by four or so dry days and sunshine.

By 4 p.m. Wednesday, Santa Rosa had received 1.29 inches of rain in 24 hours. That brought the total rainfall since Oct. 1 to 44.81 inches, essentially double the historic average for this date.

On Wednesday, the region's biggest headache appeared to be Highway 37, which was closed again near Novato in both directions for hours because lanes remained under water. The eastbound fast lane eventually opened, but the slow lane and both westbound lanes remained closed.

The heavily used highway is a major route connecting four counties, and last month it was closed or partially closed twice for nearly two weeks. Flooding there was expected once more to last for days.

“With it raining right now and with another storm coming tomorrow, we're anticipating more problems,” said California Highway Patrol Officer Andrew Barclay.

Meanwhile up the coast, road officials were contending with a crumbling stretch of Highway 1 north of Jenner.

Vehicles Wednesday were still able to use one lane along a damaged road section in the switchback grade north of Russian Gulch. But officials might close the stretch to all traffic if the road keeps sinking, said Ken Wells, a Caltrans maintenance supervisor in Fort Ross.

Some parts of the road have dropped 4 to 5 feet, he said.

In Guerneville, the Russian River crested Wednesday morning at 33.9 feet, almost two feet above flood stage. That was slightly lower than expected, and no major problems were reported.

Forecasts call for the river to fall below the flood level of 32 feet early Thursday and then, because of expected rains, to rise again and crest at 35.4 feet about 10 a.m. Friday morning.

On Wednesday, the county reported 31 closed roads, mainly from flooding, downed trees and mudslides.

In the hills above the river, a section of Old Cazadero Road broke off and slid down the hillside Tuesday morning. The damage effectively cut off Wildwood Retreat, a popular group retreat center located about six miles from the center of Guerneville.

“The washout is the only way in or out,” Martin Meier, the center's general manager, said Wednesday.

Meier has canceled this weekend's scheduled group booking and has spoken with county roads officials. They are weighing repair options, some of which he said could take at least three months to complete.

River watchers and first responders on Wednesday said they were waiting to see what Thursday's storm would bring.

“The next thing is to see how much rain we get tomorrow and see how many more slides we get,” said Monte Rio Fire Chief Steve Baxman. “We're crossing our fingers.”

County schools closed because of weather Wednesday were Guerneville School and Monte Rio Union School District.

In Lake County, officials said Clear Lake on Wednesday afternoon reached flood stage of 9 feet on the Rumsey gauge, a shoreline measurement based on a rock formation.

The Lake County Sheriff's Department said the lake is forecast to peak sometime Saturday near 10 feet Rumsey.

Wednesday's rain caused more wastewater overflows, this time along the Russian River and Occidental.

The Russian River County Sanitation District, operated by the county Water Agency, had wastewater overflows on River Road and at the district's main lift station on Riverside Drive, according to a press release.

Crews “are working around the clock to minimize overflows as much as possible, evaluate any impacts to public and environmental health, and will continue to monitor the collection systems,” the Water Agency stated.

A wastewater treatment pond in Occidental also overflowed Wednesday, said Water Agency spokeswoman Ann DuBay. The amounts of the overflows has yet to be calculated.

You can reach Staff Writer Randi Rossmann at 707-521-5412 or randi.rossmann@pressdemocrat.com. On Twitter@rossmannreport.

You can reach Staff Writer Robert Digitale at 521-5285 or robert.digitale@pressdemocrat.com. On Twitter @rdigit