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Santa Ana 1
Tue Sep 14, 2004
Listen in RealAudio 
Between October and February, southern California residents dread the onset of the
hot, dry Santa Ana winds, particularly in the fire-prone chaparral country. Hi, I’m Bryan
Yeaton for The Weather Notebook.
Santa Ana winds join the Chinook as American members of the föhn-wind family. Föhn
winds blow warm and dry as they drop from mountain heights, heated by compression
during descent to lower altitudes.
Southern California föhn winds originate in the arid Great Basin plateaus of Nevada
and Utah. When high pressure builds there, air is pushed westward over the Sierra
Nevada and San Gabriel Mountains toward the Pacific.
Descending to sea level increases the air’s temperature and dryness, and the push
through coastal range passes and canyons increases the speed. Santa Ana winds, by
definition, must exceed 28 mph but typically blow around 40 mph. In the extreme, gusts
can reach 110 mph when squeezed through narrow canyons.
Most common following southern California’s dry summer, Santa Ana winds produce
extreme fire hazards throughout the region. And once a fire is burning, Santa Ana
winds whip the flames, spreading and intensifying the blaze.
The Santa Anas also affect air and water travel in the Los Angeles basin, and offshore
by increasing air turbulence and piling up the waves.
A local legend associates Santa Ana winds with earthquakes. The name Santa Ana
originates from Orange County’s Santa Ana Canyon where the winds blow particularly
strong. Some argue that the wind’s original name derived from heat it contained:
"Santana," which in Spanish meant "Devil Wind." Reportedly, an Associated Press
correspondent mistakenly used Santa Ana instead of Santana in a 1901 dispatch, and
the new name stuck.
Thanks to our contributing writer, meteorologist Keith Heidorn. The Weather Notebook
is funded by the National Science Foundation and Subaru of America.
Today's Links
The Santa Ana Winds: The Science
http://www.atmos.ucla.edu/~fovell/ASother/mm5/SantaAna/winds.html
The Santa Ana Winds: The Lore
http://www.sandiegohistory.org/journal/58january/santa.htm
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