Santa Ana winds are gusting through the mountains, passes and foothills of Southern California.
Some of the strongest winds early Friday have been in the mountains of Los Angeles County where speeds have hit 67 mph.
The National Weather Service says downed trees are likely in light of rains that have saturated soil this month.
Forecasters say the northeast winds will continue into the weekend, but not quite as strongly after Friday night.
The offshore flow is expected to combine with a building ridge of high pressure to bring a warming trend pushing coastal and valley temperatures into the 70s Saturday and Sunday.
Meanwhile, freeze and frost conditions are expected through midmorning Friday in wind-protected areas of Ventura and Santa Barbara counties.