After the Mountain fire ballooned to more than 20,000 acres in less than 24 hours, improving weather conditions helped crews contain more of the blaze on Saturday.

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.