Although the strongest wind gusts have passed through the Southern California region, another "traditional Santa Ana wind event" will move in Thursday night.

Multiple wildfires are currently raging through Los Angeles County, forcing evacuations and destroying neighborhoods. A long dry summer created ample fuel that has combined with a lack of rainfall over the winter to extend fire season conditions.

Jon Keeley, a research ecologist in California with the U.S. Geological Survey and adjunct professor at UCLA, explains what causes extreme winds like this in Southern California, and why they create such a dangerous fire risk.