Big winter storm exits North Bay with more flooding, hail and snow

The winter storm that has battered the North Bay for much of the week landed its final blows Friday, with hail and even some snow punctuating a system that led to widespread flooding and road closures, including highways serving Sonoma, Marin and Napa counties.

The 24-hour rainfall total by Friday evening - at more than an inch in the hills west of Healdsburg and half as much in ?downtown Santa Rosa - didn’t measure up to previous days in the storm, the biggest of the winter. But the accumulated runoff pushed the lower Russian River to a crest of nearly 35 feet early Friday morning in Guerneville. Flood stage is 32 feet in the ?area.

The storm also caused flooding outside of Novato that closed westbound Highway 37, likely for a week or more, officials said late Friday. A rock slide shut a segment of Highway 128 between the intersection with Highway 121 in Napa County and the western outskirts of Winters in Yolo County.

Tahoe-bound travelers were stalled by another round of heavy snowfall and poor visibility that closed Interstate 80 and Highway 50 for hours ahead of a three-day holiday.

The cold front that pushed in behind the storm’s warmer, moisture-laden atmospheric river also led to snow falling on Highway 1 in coastal Mendocino County, and on the Mayacamas Mountains dividing Sonoma and Lake counties.

Since Tuesday, the storm has dumped 13.84 inches on the region’s wettest spot, Venado, in the hills west of Healdsburg. The total at Charles M. Schulz-Sonoma County Airport was 5.52 inches.

The region’s two main reservoirs, Lake Sonoma and Lake Mendocino, have absorbed more than their seasonal capacity for this time of year, with both at more than 100 percent, triggering releases to restore room for flood storage.

Lake Sonoma reported 112 percent of capacity, while Lake Mendocino was at 126 percent.

Nick Malasavage, chief of operations and readiness at the Army Corps of Engineers office in San Francisco, said the levels will come down starting Saturday as dam managers release water back into the Russian River watershed after the flood danger passes. The week’s storm came and went with the expected amount of rainfall and caused no unusual issues, he said.

“Through the storm, we were releasing a minimal amount of water. I don’t want to casually call it routine operations, but that’s what the facilities are designed for,” he said. “There was not anything specific that set the storm different or aside from other storms of this magnitude.”

About 14 roads in Sonoma County remained fully or partly closed Friday evening. They included snow-draped Pine Flat Road in Healdsburg, San Antonio Road in Petaluma and Mark West Station Road in Windsor.

After it crested at 1 a.m. Friday, the Russian River began to subside, reaching a projected 29 feet by 10 p.m., the National Weather Service reported.

Aside from debris in roads and a few mudslides, the storm hadn’t caused many issues in the lower river area, said Monte Rio Fire Chief Steve Baxman.

“The good news for this high-water exercise is nobody got hurt and there was no major damage to any houses, so we’re ahead of the game,” Baxman said.

Three school districts - Dunham Elementary, Monte Rio and Guerneville - were closed Friday, the Sonoma County Office of Education reported.

Rain is expected to linger through the weekend in the North Bay, with showers tapering off by Saturday afternoon.