Winter storm to bring hail, snow, rain and thunderstorms to Sonoma County

Sonoma County residents may get a glimpse of more light snow Thursday morning before heavy winter conditions roll through the North Bay in the afternoon bringing rain, high winds and even more snow, forecasters said.

Scattered rain showers and light snow fell Wednesday afternoon across Sonoma County with patches of hail reported just after 1:30 p.m. in Santa Rosa and Rohnert Park.

Remnants of snow may be visible Thursday morning until clouds move in and heavier precipitation leaves behind snow-capped mountains that may not be seen until Friday.

“That’s when we really get our first break in the clouds,” said Rick Canepa, a meteorologist with the National Weather Service’s Bay Area office in Monterey.

Nearly all of Sonoma County is expected to experience snowfall by Thursday morning. Forecasters predict less than an inch in the valleys and larger amounts at elevations higher than 1,000 feet.

Mount St. Helena could receive up to 1½ feet closer to its summit and areas between 1,500 to 2,500 feet could get up to 4 inches, according to Warren Blier, another National Weather Service meteorologist.

He said there was a 10% to 20% chance of snow accumulating in northern Sonoma County near Cloverdale and Healdsburg.

“I can’t completely rule it out, but it is not what we are expecting,” Blier said.

Daniel Virkstis, a county spokesperson, said the county’s Public Infrastructure Department has been sanding roads across the region during early morning periods.

“Road crews will be monitoring trouble spots and respond to community concerns throughout the weekend in support of safe roadway travel,” he added.

California Highway Patrol Officer Olegario Marin, with the Ukiah office, said motorists should drive slow and have chains if they’re entering snowy areas in that region.

They also should give themselves more time to reach their destinations, especially if road closures occur overnight.

“That may be something that does happen,” Marin said, adding that highways 101, 175 and 253 are among the areas that may require caution.

Sonoma County will be under a freeze warning through 9 a.m. Thursday due to low temperatures that are expected to dip as low as 28 degrees in Santa Rosa and 30 degrees in Rohnert Park.

In anticipation of the cold, Santa Rosa has opened a warming center at Caritas Center, 301 6th St. Suite 108, through Saturday.

Rain, wind and falling trees

A heavier round of rain is expected later Thursday morning and snow will return in the afternoon into Friday morning.

The storm is expected to drop a total of ½ to 1 inch of rain in some areas, like Santa Rosa and Healdsburg, and up to 1½ inches across the majority of Sonoma County.

Scattered showers will spread across the North Bay until Thursday night when the rain will become more widespread and then fade Friday night, Blier said.

There will be a 20% chance of thunderstorms and small hail throughout the area from Thursday through Friday, with a higher chance Thursday afternoon into Friday morning. Blier said there is a slightly higher chance of thunderstorms near the coast but otherwise it is very hard to predict exactly where the thunderstorms could hit.

Wind gusts will also develop Thursday afternoon, Blier said.

They will follow high winds that developed across Sonoma County Tuesday afternoon and were responsible for toppling trees into power lines and homes.

“It will get breezy,” Blier said, “but nothing like what we just went through.”

Tuesday afternoon, gusts ranged from 40 to 50 mph in the North Bay. Santa Rosa’s maximum wind gust was 53 mph. They reached 41 mph in Petaluma and 42 mph in Bodega Bay.

Thursday’s wind in Sonoma County valleys will range from 10 to 20 mph with gusts up to 25 mph. Hillside wind should be closer to 20 to 25 mph.

Santa Rosa Fire Marshal Paul Lowenthal said there is potential for falling trees because of how many were damaged by January’s rainstorms and Tuesday’s winds.

Fire officials across Sonoma County said they experienced high call volumes from Tuesday afternoon to about 8 p.m., when gusts became more infrequent.

The Sonoma County Fire District received its final weather hazard call around 9:20 p.m. Tuesday, when a tree was reported down near the Charles M. Schulz-Sonoma County Airport, Sonoma County Fire spokesperson Karen Hancock said.

Residents should call an arborist or specialist if they have trees that are uprooted or with branches that are beginning to break, Lowenthal said.

“A lot of those trees that came down had been weakened by recent storms,” he said.

Monte Rio Fire Chief Steve Baxman said there is also the risk of trees falling if the rain and ice covers dry and weathered trees.

“The trees don’t take the weight,” he said. “The trees will start toppling over.”

Press Democrat reporter Colin Atagi contributed to this story

You can reach Staff Writer Madison Smalstig at madison.smalstig@pressdemocrat.com. On Twitter @madi.smals.