Gusts up to 60 mph will sweep the Conejo Valley starting Thursday, Oct. 15, as the season's first Santa Ana winds arrive. The National Weather Service in Oxnard issued Red Flag Warnings and Fire Weather Watches across much of Southwest California on Tuesday, Oct. 13.

The Red Flag Warning takes effect Thursday at 6 a.m. and runs through Friday, Oct. 16, at 10 p.m., according to the NWS Los Angeles forecast office. A separate Fire Weather Watch covers Friday from 3 a.m. to 6 p.m.

What to expect

Sustained winds of 20 to 40 mph and gusts of 40 to 60 mph are forecast between Thursday afternoon and Friday afternoon, NWS meteorologist Ryan Kittell told the Los Angeles Times. Mountain locations could see gusts up to 70 mph.

Humidity is expected to drop to between 5% and 15%. High temperatures could reach 85 to 95 degrees. Vegetation is very dry, Kittell said.

"There's a high risk for any new fires to grow really fast," Kittell said.

The NWS said any fire that ignites under these conditions could show extreme behavior and rapid growth. Downed trees, downed power lines and power outages are also possible.

Ventura County faces elevated risk

Climate scientist Daniel Swain of UC Agriculture and Natural Resources said areas west of the 405 Freeway, including Ventura County, face especially high fire danger. The region received almost no rain from post-Tropical Storm Rachel and then endured a record-breaking heat wave in early October, Swain said.

The NWS also issued High Wind Watches and Wind Advisories for Thursday through Friday, with additional advisories possible Saturday. Heat advisories are in effect as well, warning of moderate heat-illness risk for all populations.

Safety steps

The NWS urged residents to avoid any activity that could create a spark, build an evacuation plan, prepare for power outages, secure outdoor objects and holiday decorations, and stay hydrated.

CAL FIRE issued a separate warning on Threads that sparks from powered grinders have been linked to at least three recent California wildfires. The agency advised moving grinding work away from dry vegetation onto cleared, noncombustible surfaces. If that is not possible, clear surrounding brush, keep water and a fire extinguisher nearby, and call 911 immediately if a fire starts.

Residents can sign up for Ventura County emergency alerts at VCAlert.org. The Red Flag Warning is set to expire Friday, Oct. 16, at 10 p.m.