They have been a part of life in Southern California longer than anyone can remember. The Santa Ana Winds have been blowing down from the high deserts to coastal plains long before people arrived in the region. They are arid and usually warm before they leave the Great Basin and Mojave Desert, and they get even warmer as they flow downhill through mountain passes. That is what makes them so dangerous during fire season. Wind alone accelerates wildfire. Warming arid wind desiccates fuel, making it more combustible before wildfire arrives.
Santa Ana Winds are so regular that they affect how tall trees grow within the regions of the mountain passes where Santa Ana Winds move the fastest. Tall Mexican fan palms that grew up straight where sheltered from wind near the ground innately lean with the prevailing wind as they grow up and become more exposed. Those closer to the narrow canyons lean the most. It is something that arborists recognize everywhere around the Los Angeles Basin. They can tell how strongly the Santa Ana Winds blow in any particular neighborhood by how Mexican fan palms lean.
Santa Ana Winds can be strong enough to break tree limbs, and blow trees down. In the past few days, they have been making quite a mess in the Los Angeles region; although not as much of a mess as they are making in conjunction with the Thomas Fire in Santa Barbara and Ventura Counties, which may already be the biggest wildfire in the modern history of California.
Overnight, Santa Ana Winds blew this California pepper tree onto a swimming pool in Los Angeles. Tree services, landscapers, gardeners and those who enjoy gardening will be busy cleaning up such problems for the next few days, as Santa Ana Winds continue.