Rain coming to Sonoma County ahead of the weekend

Scattered rain will sweep over Sonoma County beginning Friday, though rainfall totals won’t be substantial enough to trigger flooding in areas scarred by recent wildfires, weather officials say.

Low-lying parts of the county should expect to see about 0.1 inch to a quarter of an inch of rain, while totals in the North Bay mountains and the Sonoma Coast could creep closer to an inch of rain, National Weather Service meteorologist Drew Peterson said.

Rainfall is expected to start at about daybreak Friday in the northern parts of Sonoma County before sweeping south to Petaluma and continuing to the San Francisco Bay.

Showers could trail the storm into Friday night but they’re expected to clear out by early Saturday morning, Peterson said.

Forecasts showing the impending storm will be a weak one are a good sign, Peterson said. Despite the county’s dry state, too much rain could overwhelm the loose soil, ash and other debris left behind from the county’s recent fires, leading to flooding, he said.

“The last thing we want up in the North Bay is a lot of precipitation because we don’t want to test the burn scars from the fires too soon,” Peterson said. “We would need much heavier rainfall to trigger those debris flows.”

Overnight lows on Friday and Saturday night are expected to be warmer than earlier parts of the week, Peterson said. During the day, temperatures should hit the low to mid-60s on Saturday and reach up to 70 degrees on Sunday.

Monday is expected to be unseasonably hot, up to the high 70s, Peterson said.

Another period of rainy weather is possible for next week, with weather data showing a chance of rain Tuesday into Wednesday, Peterson said.

You can reach Staff Writer Nashelly Chavez at 707-521-5203 or nashelly.chavez@pressdemocrat.com. On Twitter @nashellytweets.