Alaska-born storm set to bring rain, wind, snow to Sonoma County
A storm born in the Gulf of Alaska is expected to bring the first heavy rain of the new year to Sonoma County on Wednesday night along with strong winds and a dusting of snow in the mountains, but it will move out in 24 hours and leave the area drier than usual for this time of year.
Will Pi, a National Weather Service meteorologist called it a “moderate storm,” expected to deliver 1 to 2 inches of rain across the North Bay by Thursday night — an amount that isn’t expected to cause problems, other than impacting the Thursday morning commute, he said.
But it will break the relatively dry spell that has seen just one-third of an inch of rain in Santa Rosa so far in January, typically the wettest month of the year with a 30-year average of 7.05 inches here.
Santa Rosa got 11.2 inches of rain in December, well above the monthly average of 7.03 inches, and may be counting on a damp February — which averages 6.4 inches — to catch up, Pi said.
On Tuesday, the city was at 13.70 inches for the rain season that began Oct. 1, about one-third of the 36.28-inch seasonal average.
Rain was forecast to fall hard enough from Wednesday night to Thursday night to cause minor urban flooding around the Bay Area, the official forecast said, but Pi noted the ground will absorb water after a few comparatively dry weeks, averting overflows from streams and rivers.
“This is the way we like storms, a couple of inches at a time,” said Barry Dugan of Sonoma Water, the agency that delivers Russian River water to 600,000 Sonoma and Marin county residents.
Creeks are low and the Russian River in Guerneville was at 5.6 feet Tuesday. The river was expected to crest at about 12 feet on Friday, far below the flood stage at 32 feet.
Winds gusting up to 40 mph may precede the rain Wednesday night in Sonoma County, with the strongest winds at the coast and at higher elevations, diminishing Thursday morning, Pi said.
Rain will continue Thursday, with a “small chance” of thundershowers in Sonoma County, and tapering off Thursday evening, he said.
Snow is expected to start falling late Wednesday night and into Thursday as temperatures drop, bringing snow levels down to about 3,000 feet. Mount St. Helena, at 4,300 feet, could get 1 to 3 inches of the white stuff, Pi said.
Daytime temperatures will remain in the low 50s through the work week, warming up to near 60 on a partly sunny Sunday.
You can reach Staff Writer Guy Kovner at 707-521-5457 or firstname.lastname@example.org. On Twitter @guykovner.