Weather: The Santa Anas

"Named after Southern California's Santa Ana Canyon and a fixture of local legend and literature, the Santa Ana is a blustery, dry and warm (often hot) wind that blows out of the desert. In Raymond Chandler's story Red Wind, the title being one of the offshore wind's many nicknames, the Santa Anas were introduced as 'those hot dry [winds] 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.' Local legends associate the hot, dry winds with homicides and earthquakes, but these are myths.



"Another popular misconception that the winds are hot owing to their desert origin. Actually, the Santa Anas develop when the desert is cold, and are thus most common during the cool season stretching from October through March. High pressure builds over the Great Basin (e.g., Nevada) and the cold air there begins to sink. However, this air is forced downslope which compresses and warms it at a rate of about 10C per kilometer (29F per mile) of descent. As its temperature rises, the relative humidity drops; the air starts out dry and winds up at sea level much drier still. The air picks up speed as it is channeled through passes and canyons...." -- from the website.

<http://www.atmos.ucla.edu/~fovell/ASother/mm5/SantaAna/winds.html>