A Santa Ana wind event is fueling wildfires in Los Angeles that have destroyed homes and forced the evacuation of thousands of people. Here’s what to know about the winds.
How do the Santa Ana winds work?
The Santa Ana winds are the strong, dry and often warm winds that blow west from Nevada and Utah to Southern California.
The winds occur in the colder months, when low- and high-pressure weather systems intensify across the mid-latitudes of the northern hemisphere, said Alex Hall, director of the Institute of the Environment and Sustainability at the University of California, Los Angeles. Sometimes, an area of high pressure can become locked in place over the arid, mountain-bound area known as the Great Basin, which covers much of Nevada, part of Utah and portions of other states, because of its unique geography.
To understand how the Santa Ana winds form, Mr. Hall said, imagine the Great Basin as “a big bowl,” topographically speaking, its sides lined with holes representing mountain passes. “If you have a lot of heavy, high pressure sitting there in the bowl, you’re going to be pushing air out through the holes,” he said…