Santa Anas are dry, warm and gusty northeast winds that blow from the interior of Southern California toward the coast and offshore, moving in the opposite direction of the normal onshore flow that carries moist air from the Pacific. They typically occur during the fall months and continue through winter and into early spring.

The fast-moving Mountain fire forced thousands to evacuate and destroyed neighborhoods in the hilly communities of Ventura County. “We figured we were trapped,” one resident said.