Fire weather watch issued for large swath of California

Bone-dry air and powerful wind gusts are expected to bring the perfect recipe for rapid wildfire spread across parts of Northern California this weekend, and the National Weather Service issued a series of fire weather watches on Thursday to start ringing the alarm bells.

Portions of Trinity, Lake and Mendocino counties will be under a watch Friday night through Sunday afternoon, the weather service said. The fire risk is expected to be high, with humidity levels dropping into the teens and winds up to 50 mph on ridgetops in far Northern California.

To the south, most of the Bay Area will fall under a watch from 5 a.m. Saturday to 5 p.m. Sunday. Wind speeds in the Bay Area could reach 45 mph on Saturday afternoon into Sunday, with the most powerful gusts on ridgetops above 1,000 feet of elevation. Daytime humidity levels in the Bay Area could dip down to 15% to 20%. “Please stay up to date on the forecast, and use extreme caution when recreating outdoors,” the weather service’s Bay Area office said. 

The weather service’s Sacramento office issued a watch for portions of the Sacramento Valley and Sierra Nevada foothills early Saturday into Sunday. Humidity levels could dip to 10% to 20%. “The combination of gusty winds and low humidity can cause fire to rapidly grow in size and intensity,” the weather service’s Sacramento office said. “Outdoor burning is not recommended.”

The critical fire weather ix expected to occur as an upper-level low moves through the Great Basin in Nevada. 

“We’re going to get offshore flow in Northern California,” said Brayden Murdock, a meteorologist with the weather service. “The winds will start out northerly and then switch to northeasterly. When we get northeast winds, it means they’re typically going to be dry.”

This breaking news story has been updated.