Santa Ana winds in Southern California are often-fierce winds that topple power lines and trees and can turn a spark into a raging wildfire.

The winds are common in California in the colder months, but they can sometimes help spread dangerous wildfires.

Southern California faces a "extremely critical fire weather" that will likely result in "widespread" downed trees, power lines and electricity outages this week, the National Weather Service warns. Threat level: Rare,