<P> The Santa Anas are katabatic winds--Greek for "flowing downhill", arising in higher altitudes and blowing down towards sea level . Santa Ana winds originate from high - pressure airmasses over the Great Basin and upper Mojave Desert . Any low - pressure area over the Pacific Ocean, off the coast of California, can change the stability of the Great Basin High, causing a pressure gradient that turns the synoptic scale winds southward down the eastern side of the Sierra Nevada and into the Southern California region . Cool, dry air flows outward in a clockwise spiral from the high pressure center . This cool, dry airmass sweeps across the deserts of eastern California toward the coast, and encounters the towering Transverse Ranges, which separate coastal Southern California from the deserts . The airmass, flowing from high pressure in the Great Basin to a low pressure center off the coast, takes the path of least resistance by channeling through the mountain passes to the lower coastal elevations, as the low pressure area off the coast pulls the airmass offshore . </P> <P> These passes include the Soledad Pass, the Cajon Pass, and the San Gorgonio Pass, all well known for exaggerating Santa Anas as they are funneled through . As the wind narrows and is compressed into the passes its velocity increases dramatically, often to near - gale force or above . At the same time, as the air descends from higher elevation to lower, it is heated adiabatically, warming about 5 ° F for each 1,000 feet it descends (10 ° C for each 1,000 m). As it warms, its capacity to hold moisture increases, so its relative humidity decreases . The air has already been dried by orographic lift before reaching the Great Basin, as well as by subsidence from the upper atmosphere, so this additional warming often causes relative humidity to fall below 10 percent . The end result is a strong, warm, and very dry wind blowing out of the bottom of mountain passes into the valleys and coastal plain . </P> <P> During Santa Ana conditions it is typically hotter along the coast than in the deserts, with the Southern California coastal region reaching some of its highest annual temperatures in autumn rather than summer . </P> <P> While the Santa Anas are katabatic, they are not Föhn winds . These result from precipitation on the windward side of a mountain range which releases latent heat into the atmosphere which is then warmer on the leeward side (e.g., the Chinook or the original Föhn). </P>

Where did santa ana winds get their name