Sonoma County could get up to 3 more inches of rain this week

The storm door that swung open for Thanksgiving dropped two to four inches of rain on Sonoma County last week, with a virtual rainy repeat expected from three wet, breezy days starting around noon Tuesday.

Santa Rosa got 2.94 inches of rain Wednesday through Saturday, while Rohnert Park got 3.45 inches, Healdsburg 2.44 inches and Petaluma 2.02 inches. Cazadero, typically the county's wettest spot in the coastal hills, recorded 4.44 inches, the National Weather Service said Monday.

The first of two consecutive storms is expected to start about noon today in the North Bay, with rain that could be heavy at times and winds of 20 to 30 mph, meteorologist Steve Anderson said.

Those conditions will prevail through Thursday, dropping one to three inches of rain in the region, he said, calling it “typical for this time of year.”

Anderson added a warning, however, that strong wind on the coast will generate ocean swells of 13 to 17 feet through Friday.

Last week's rains broke an unusually dry spell that saw just 1.23 inches of rain in Santa Rosa since Oct. 1, making it the 62nd driest October on the books since 1902.

Santa Rosa, Sebastopol, Windsor and Cloverdale now had at least 4 inches since Oct. 1, while soggy Cazadero has gotten 7.22 inches.

“It was a great run, a good start to the season,” said Joe Pozzi, a Valley Ford sheep and cattle rancher.

Early rain, falling while the soil is still warm, stimulates growth of pasture grasses and germinates seeds before winter's chill sets in, he said. Livestock ranchers save money as their animals eat natural grass instead of commercial feed.

Anderson said last week's precipitation has “pretty well soaked in,” leaving the ground ready to absorb the upcoming rain.

Jan Null, a Saratoga-based meteorologist, said the two weeks of moderate storms - “not too small and definitely not too large” - are ideal for a region in need of water but wary of the harm that could come from mudslides triggered by heavy rain on land scorched bare by wildfires.

November is turning out to be a “catch-up month” after the arid October, he said.

Null reported that last week's rain boosted Santa Rosa from 25 percent of normal precipitation on Nov. 20 to 68 percent of normal four days later. Ukiah went from 25 percent to 60 percent of normal over the same period.

The Western Regional Climate Center's latest map showed nearly all of Sonoma County had from 50 percent to 70 percent of average precipitation from Oct. 1 through Sunday.

Lake Sonoma, the region's largest reservoir northwest of Healdsburg, was at 76 percent of targeted water supply Monday, while Lake Mendocino near Ukiah was at 98 percent.

“Let's keep our fingers crossed that last week's rain and the expected rain this week are a sign of things to come this winter,” said Ann DuBay, spokeswoman for Sonoma Water, which delivers water from the two reservoirs to more than 600,000 Sonoma and Marin county residents.

You can reach Staff Writer Guy Kovner at 707-521-5457 or guy.kovner@pressdemocrat.com. On Twitter @guykovner.