Santa Ana winds will pick up again Friday when a fire weather warning remains in effect for most of Southern California.
A red flag warning was scheduled to expire at 4 p.m. Friday, but it was extended to 4 p.m. Saturday for a widespread part of the region due to the winds, combined with above-normal temperatures and dry conditions. It could be extended again into Sunday.
The warning area includes the Santa Monica Mountains Recreational Area, Los Angeles County mountains, Angeles National Forest and the Santa Clarita and San Fernando valleys. A separate red flag warning will also be in place during the same hours in inland Orange County and the Santa Ana mountains.
Large swaths of Riverside and San Bernardino counties also will see increased fire danger.
Fires in Thousand Oaks and the San Jacinto Mountains community of Mountain Center forced evacuations. Firefighting air tankers and helicopters responded late Thursday morning to a brush fire in Angeles National Forest. The Hogsback Fire burned about 3 acres along Mt. Baldy Road.
Temperatures will be in the 70s and even 80s in some areas. Mountain highs will reach the 60s. Riverside might break a record high with temperatures climbing into the mid-80s.
“The winds and the temperatures, they’re going to hand in hand,” said NBC4 forecaster Belen De Leon. “Those down-sloping Santa Ana winds, they warm the air and compress it.”
If a fire starts during red flag conditions, it can rapidly spread when flames are fanned by strong and, sometimes, shifting winds. Rainfall has been scare during what’s usually the wettest time of the year, leaving SoCal with hillsides covered in dry brush.
Winds began building Wednesday afternoon in some areas, most notably in the western San Fernando Valley, where gusts of 35 to 45 mph were reported. A high pressure system was building and advancing into the area, and that will bring warm and dry conditions, pushing humidity levels down, possibly into the 5 to 10% range.
North to northeast winds will form over Los Angeles and Ventura counties and continue through Friday. Wind gusts of 30 to 50 mph are anticipated across much of the area.
Winds are expected to die down Saturday night through Sunday, but they'll pick up again Monday through Tuesday or Wednesday.