Devil Winds : Flowing from Desert to Mountain to Sea

It’s the season for Santa Ana winds, and with them comes the reminder of the wildfires last fall that claimed 1,241 structures, almost 200,000 acres and $1 billion in damages. Three people lost their lives.

Santa Anas usually occur in autumn and sometimes in winter, knocking out power, tripping burglar alarms and whipping up other bits of mischief.

The phenomenon originates hundreds of miles from Southern California in a high-pressure system over Utah and is generally strongest in the Riverside-San Bernardino area.

Santa Ana winds move through the mountains from the north-northeast, funneling through the canyones into the basin. The heat of the wind is more the result of its downhill motion than its movement across the desert. This is the path: 1. Air is cool and holds fair amount of moisture. 2. Air loses moisture as it moves up the mountains. 3. Wind speed increases as air funnels through mountain passes. 4. Temperature of the air increases 5.5 degrees for every 1,000 feet it descends. 5. Air that passes over and through mountains has lost almost all moisture. *

Tracing the Name There are many theories as to why the winds are called Santa Anas. Some believe the name comes from ‘Satanas,’ Spanish for Satan. But it is generally accepted that they are named for Santa Ana Canyon, the narrow gap in the Santa Ana Mountains in Orange and Riverside counties, where the winds are especially strong.

Contributing Factors Dry cold fronts passing through the Great Basin states are followed by a high-pressure system over the Utah-Nevada border, creating westerly winds that eventually become Santa Anas. *

“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” *

How Other Winds Compare Sustained winds from Santa Anas generally range from 15 m.p.h. or less for a weak system to 35 or 40 m.p.h. for a strong one, although gusts of up to 90 m.p.h. have been recorded in mountain and canyon passes in San Bernardino County. Here are generally assigned values for sustained wind speeds for other storms: Sandstorm: 30 m.p.h. or more Dust Storm: 30 m.p.h. or more Tropical depression: 38 m.p.h. or less Tropical storm: 39-78 m.p.h. Gale: 39-54 m.p.h. Severe blizzard: 45 m.p.h. or more Hurricane: 74 m.p.h. or more Sources: National Weather Service, UCLA Atmospheric Science Dept., Encylopedia Americana, Weather of Southern California Researched by JULIE SHEER / Los Angeles Times