Red flag warning given for parts of North, East Bay

The National Weather Service issued a red flag warning for the North and East Bay hills as dry winds, low humidity and drought conditions are expected to combine, raising the risk that new wildfires could spark and existing ones could spread.

The red flag warning was scheduled to take effect at 11 p.m. Sunday and last through 8 p.m. Monday. The warning will also include Concord, Livermore and other parts of the North Bay valley, said Ryan Walbrun, a meteorologist with the National Weather Service.

“The areas of biggest concern are the places that received essentially no rainfall over the last 24 hours,” Walbrun said. “That would be most of Napa County and Alameda and Contra Costa (counties) in the East Bay hills where the rain amounts were minimal — less than a tenth of an inch.”

The weather conditions could also mean power shut-offs for some parts of the area, including Sonoma, Napa and Solano counties, according to Pacific Gas and Electric Co. The company issues “public safety power shutoffs” to prevent power lines from starting blazes when gusty winds and dry conditions could bring risky fire weather.

The strongest winds were expected to begin Sunday night around 11 p.m. in the hills around Napa and eventually, spread over the North and East Bay hills, according to the National Weather Service. Wind speeds will reach up to 25 mph with gusts reaching 45 mph.

Humidity levels are expected to drop by Monday as temperatures could soar, causing “critical” fire weather, Walbrun said.

Walbrun added that the red flag warning is moderate, but given drought conditions, if a fire ignites, it could cause “large fire growth.”