Santa Ana winds are common in Southern California during cooler months. Here’s a look at the often-fierce winds that topple power lines and trees and can turn a spark into a raging wildfire.

Red Flag Warnings remain in effect through Friday evening for much of Los Angeles and Ventura Counties, the National Weather Service said.

At least 10 people are believed to be dead -- with the LA County sheriff saying he expects that number to rise -- as a series of devastating fires grow uncontained across Southern California amid dry and windy conditions,