Snow, frost and fire danger? Wild weekend ahead

Frost, fire warnings and Sierra snowfall should make for interesting times around Northern California this weekend, as gusty winds and a cold air mass coming down from the north force late summer to compete against wintery conditions for dominance.

“And all within a few miles of each other,” Chris Jordan, a National Weather Service meteorologist said from the Reno office Friday morning. “That’s fall for you. As we transition seasons, everything happens at once.”

The rain of a week ago did little to quench the parched conditions that leave parts of Northern California ripe for wind-driven wildfires, prompting red flag warnings for Sonoma, Lake and Napa counties, as well as the Bay Area and large swaths of inland California, meteorologists said.

But there’s also frost in the forecast for cooler areas and higher elevations of Mendocino County over the next three nights, with temperatures in the coldest places dipping below 30 degrees, the National Weather Service said.

“It looks like interior Mendocino is expecting widespread frost and, on the coast, more patchy,” Treena Hartley, a meteorologist from the National Weather Service’s Eureka office said Friday morning.

Though frost was not a part of the forecast for Sonoma County, residents can still anticipate chilly evenings in the low-40s and cooler daytime temperatures in the mid-70s, said Steve Anderson, from the weather service in Monterey.

But the cool air coming south is also dry, meaning low relative humidities will combine with strong winds to raise the risk of fire danger until at least Saturday evening, weather officials said.

The cold air mass, meanwhile, brought snow flurries Friday morning to the Sierras, where a occasional snow should continue through the weekend, Jordan said.

“Because of the showery pattern, we’re not looking at any widespread snowfall accumulation,” Jordan said.

The snow, moving down from the north instead of its usual easterly route off the Pacific, will fall mainly on the eastern Sierras and western Nevada, Jordan said.

But it will be cold enough at high elevations - it was 12 degrees at 10,000 feet around 9 a.m. — that at least one ski resort west of Truckee has begun making snow, hoping to get a start on an early ski season.

“We’re making snow right now,” Jon Slaughter, public relations manager for Boreal Mountain Resort, said Friday morning.

While the resort was in part testing out a new $1.6 million snow making system, the main goal was to begin accumulating snow for a special event Oct. 25, he said.

Though warming temperatures beginning next week might melt some of it, there should be some accumulation, he said.

“I’ve looked on line, and I haven’t found anyone else who is making snow in Tahoe,” Slaughter said.