“There was a desert wind blowing that night. It was one of those hot, dry Santa Anas that come down through the mountain passes and curl your hair and make your nerves jump and your skin itch. On nights like that, every booze party ends in a fight, meek little wives feel the edge of the carving knife and study their husbands’ necks. Anything can happen.”
--Raymond Chandler “Red Wind” *
The Santa Ana winds are coming and that’s good news and bad news. Good for blowing pollutants out of the San Fernando Valley, bad for fanning wildfires at a time when brush is at its driest.
The winds have spread many memorable fires, including the 1961 Bel-Air fire that destroyed hundreds of homes. Fire officials estimate that ires pushed by Santa Anas spread five to six times faster than other brush fires.
This regional phenomenon begins in late summer and last through autumn, sometimes into winter, knocking out power, tripping burglar alarms and sending tumbleweeds hurtling across freeways. Santa ana conditions begin hundreds of miles from Southern California and are generally strongest in the Riverside-San Bernardino area.
The topography and position of the San Fernando Valley put it on target for the hot, dry winds that begin in a high-pressure system over Utah and snake through mountains and desert on their way to the ocean. Gusts up to 60 m.p.h. have been recorded in the Valley.
It’s said people act strange during Santa Anas. As Joan Didion put it: “It is the season of suicide and divorce and prickly dread, whenever the wind blows.”
Flowing from Desert to Mountain to Sea
Santa Ana winds move through the San Gabriel Mountains and approach the Valley from the north/northeast, funneling through the Soledad CAnyon and Weldon Canyon area into the Valley.
The heat of the wind is more the result of its downhill motion, rather than its movement across the desert.
Tracking the Wind
Dry cold fronts passing through the Great Basin states are followed by a high pressure system that is centered over the Utah-Nevada border, creating westerly winds that eventually become Santa Anas.
Where the Name Comes From
There are many theories, some legendary, as to why the winds are called Santa Anas. Some believe the name comes from Satanas, Spanish for Satan. But most likely they are named for the Santa Ana Canyon, the narrow gap in the Santa Ana Mountains in Orange and Riverside counties, where the winds are especially strong.
* 1. Air is cool and holds fair amount of moisture. 2. Air loses moisture as it moves up mountains 3. Wind speed increases as air funnels through mountain passes. 4. Air temperature increases 5.5 degrees for every 1,000 feet it descends. 5. Air that passes over and through mountains has lost almost all moisture
More Hot Air
Like the Santa Anas, other hot, dry winds occur elsewhere in the world.
* CHINOOK: Native American word meaning “snow eater,” the Chinooks blow east of the Rocky Mountains and are common in Denver.
* FOEHN: Occuring in the Alps, they blow in winter when warm air over the mountains is forced to descend.
* KHAMSIN: Originating in Egypt and moving eastward into the Middle East, it remains hot and dry because it does not cross a vast expanse of water.
* Sirocco: hot, dusty wind from the Sahara. Forms ahead of cyclones moving eastward across North Africa and the southern Mediterranean in the spring. Cools as it crosses the mediterranean Can bring rain and fog to southern Europe.
* Sources: National Weather Service, UCLA Atmospheric Science Dept., Encylopedia Americana, Weather of Southern California