Los Angeles County saw multiple wildfires erupt as "extremely critical fire weather" from dry conditions and Santa Ana winds threatened Southern California into Wednesday, and the National Weather Service warned the worst was yet to come.

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 Santa Ana winds occur when there is high pressure to the east, in the Great Basin, and a low-pressure system off the coast. Air masses move from high pressure to low pressure, and the more extreme the difference in the pressure, the faster the winds blow. Topography also plays a role.