The Santa Ana winds are fast easterlies that blow from the desert over southern California each winter. Warm or hot and blustery, they dry out vegetation and increase the danger of and from wildfires. They also lead to choppy surf and cause turbulence and wind shear that endanger aviation.
In real life and legend, the Santa Ana winds also fray human nerves. Writers including Raymond Chandler (Red Wind) and Elizabeth George (A Place of Hiding) have portrayed them in connection with stories of violence.
In northern California, the hot, dry Diablo winds originate in Diablo Canyon. Every 10 to 20 years, according to Catherine Traywick, these winds, hot and dry after passing over the desert, combine with drought and flammable foliage like eucalyptus to cause damaging wildfires east of San Francisco Bay. They blow fast at right angles to the mountains and are funneled down canyons at great speed in their rush to equalize air pressure.