As Legend Has It, Santa Ana Means an Ill Wind Blows

Just what was the weather phenomenon that shrieked viciously out of the Mojave and into the Southland this week, upending tractor trailers, catapulting pine trees through tile roofs, fanning fires, ripping down power lines and leaving hairdos, yards and nerves a mess?

Author Raymond Chandler about 50 years ago painted the Santa Anas as sinister, hot, dry winds that “curl your hair and make your nerves jump and your skin itch. On nights like this . . . meek little wives feel the edge of the carving knife and study their husbands’ necks.”

Meteorologist Dan Bowman on Friday preferred to describe the legendary local winds in terms of bathtubs.

What happened this week to generate the cool Santa Anas, Bowman explained, is that a high-pressure system developed over the Pacific Northwest at the same time that a low pressure system was perched along the Mexico border. The winds tend to flow from high to low pressure.

Can Be Cool, Hot

“It’s like a bathtub. Picture the drain over northwest Mexico, and the high part of the tub over Washington state. Air, like water, whirls around as it rushes toward the drain.”

Santa Ana winds can occur any time of year and can be either cool or hot, depending on the season and where the high pressure is formed, explained Bowman, who works for WeatherData Inc., which provides forecasts for The Times. The coolest Santa Ana winds are those that originate with a high pressure system in Canada and bring the cooler temperatures with them.

While many people believe that the Santa Anas are merely hot air from the Mojave Desert blowing into the Southland, that is only sometimes true, he said. The warmer and drier winds come from high-pressure areas in the Pacific Northwest. In general, the winds heat up because of the downslope: as they go from higher to lower altitudes they gain almost 5 degrees every 1,000 feet they descend, he added.

Extremely Low Temperatures

But even though this week’s Santa Anas originated in the Northwest, they remained cool because they passed through the extremely low temperatures of the Great Basin area of Nevada, Bowman said.

The Santa Anas gain much of their force as they tear through the mountain passes and are compressed by the canyon walls. But unlike hurricanes and gales, Santa Ana winds are not defined by their speed. While most are clocked at around 35 to 45 m.p.h., some gusts this week exceeded 70 m.p.h.

Santa Ana-like conditions, while not a common weather feature worldwide, do occur when geography and meteorology are just right. Two of the most well known are the Fohn winds of Norway and the Chinooks from the Rockies.

There are many versions blowing around as to why the local winds are called Santa Anas, and most are just the stuff of legend, historians say. Some stories say that the name was actually Satanas, Spanish for Satan. Others insist it came from the Indian term for devil wind, though scholars say there was no such term. Still others theorize that the winds were named after the Mexican General Antonio Lopez de Santa Anna, whose cavalry stirred up clouds of dust during military campaigns. But most agree it comes from the mountain range and canyon, where the winds stir up magnificent dust storms.

‘Season of Suicide’

The winds have also stirred up just as much debate on whether the weather causes more crimes and psychological disturbances. Author Joan Didion in her book “Slouching Toward Bethlehem” called it the “season of suicide and divorce and prickly dread, wherever the wind blows.”

Most police and psychiatric professionals have taken a dim view of such folk diagnosis. But every time there is a gritty howling Santa Ana wind, some local residents insist that it makes them feel edgy, nervous and sick. And the legend persists.