Southern California faces fire warnings amid dry, gusty winds

Southern California is expected to face powerful winds and dry weather this week that could increase the risk of wildfires.

The National Weather Service has issued red flag warnings for the mountains of Los Angeles and Ventura counties starting Sunday night, expanding across much of Southern California by Monday, including Orange County and vast stretches of San Diego County and the Inland Empire.

Forecasters cautioned that it could be the strongest and longest Santa Ana wind event so far this season, with winds as high as 50 to 70 miles per hour and gusts as strong as 80 mph in the mountains. Temperatures in the Los Angeles area are expected to range from the low to mid-70s through Wednesday.

Relative humidity is expected to be at about 15% throughout the region Sunday night, then dropping to between 5% and 10% Monday night and continuing through Thursday, according to forecasters.

The dry and windy conditions are expected to last at least until Thursday. Carol Smith, a meteorologist with the National Weather Service, said that people should be especially careful to avoid setting off any kind of spark.

“If you’ve got a trailer, make sure you’re not dragging any chains. Don’t drive off road into areas with dry brush. And never throw cigarette butts anywhere — it could have really severe consequences,” Smith said.

Forecasters also warned of the possibility that the Santa Ana winds could persist into Friday or Saturday, which may require the extension of the red flag warning. Officials advise extreme caution when using potential fire ignition sources during this time.

emily.alpert@latimes.com

Twitter: @AlpertReyes

UPDATES:

10:40 a.m. Dec. 3: This article was updated with new information from the National Weather Service.

This article was originally posted at 8 p.m. Saturday, Dec. 2.