Heavy rain and wind expected to arrive midweek could bring flooding, power failures and mudslides in Sonoma, Lake and Mendocino counties, forecasters warned Monday.
Three back-to-back storms heading from the central Pacific toward the North Coast are "very unsettled, very wet and quite windy," said forecaster Bob Benjamin of the National Weather Service in Monterey.
"If anybody is near any flood-prone areas, they should certainly be taking precautions right now," he said.
The rains were expected to start late today or early Wednesday, with little or no break between the three storms that will swing through the region "like spokes in a wheel," he said.
As much as 7 inches of rain is expected to fall in Lake County between Wednesday and Sunday, prompting forecasters to issue a flood watch.
The rains could overwhelm small creeks and streams and areas burned by wildfires that cannot absorb the water, said Sacramento-based meteorologist Stefanie Henry.
Clear Lake may rise a half-foot but that will not bring it close to flood levels, Henry said. The lake on Monday was at about 1.3 feet on the Rumsey scale, and minor flooding starts at 8.5 feet.
The Russian River also was expected to handle the rainfall without flooding, although the river in Guerneville is projected to leap from 5.6 feet on Wednesday to crest at 20.6 feet on Friday.
The Santa Rosa Plain could get 6 inches of rain and perhaps as much as 10 through Sunday, Benjamin said. Cazadero and other areas above 1,200 feet could get 10 to 15 inches.
For Mendocino County, lower areas could get 5 to 10 inches and south-facing slopes at higher elevations could get 10 to 15, Eureka-based meteorologist Kathleen Lewis said.