A Cal Fire vehicle at the San Diego headquarters in Rancho San Diego. Photo by Chris Jennewein
A Cal Fire vehicle at the San Diego headquarters in Rancho San Diego. Photo by Chris Jennewein

A red flag warning indicating a high risk of wildfire was in force in valley and mountain areas of San Diego County for the second consecutive day Thursday.

The National Weather Service said the warning will expire at 5 p.m. Until then, dry, windy and warm conditions will heighten the risk of wildfire in the valleys and mountains, according to the agency.

Areas of the county under red flag warning at 6:28 a.m. Thursday. Courtesy National Weather Service
Areas of the county under red flag warning at 6:28 a.m. Thursday. Courtesy National Weather Service

A red flag warning is the weather service’s most serious fire-related warning. It is generally issued amid high winds, high heat and low humidity.

The agency also issued a wind advisory for the valleys and mountains until noon, saying winds will be strongest from sunrise to mid-morning.

Sustained east winds of 10 to 20 miles per hour and widespread gusts of up to 45 mph are expected Thursday, and isolated gusts of up to 50 mph are possible through passes and canyons, according to the weather service.

“Conditions will improve somewhat by (tonight) as offshore flow weakens,” the weather service said.

— City News Service

Chris Jennewein is founder and senior editor of Times of San Diego.