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If you mean Santa ANA winds then they are generally defined as warm, dry winds that blow from the
east or northeast (offshore). These winds occur below the passes and canyons
of the coastal ranges of Southern California and in the Los Angeles basin.
Santa Ana winds often blow with exceptional speed in the Santa Ana Canyon
(the canyon from which it derives its name). Forecasters at the NWS in Oxnard
and San Diego usually place speed minimums on these winds and reserve the use
of "Santa Ana" for winds greater than 25 knots.
The complex topography of Southern California combined with various
atmospheric conditions create numerous scenarios that may cause widespread
or isolated Santa Ana events. Commonly, Santa Ana winds develop when a
region of high pressure builds over the Great Basin (the high plateau east of
the Sierra mountains and west of the Rocky mountains including most of Nevada
and Utah). Clockwise circulation around the center of this high pressure
area forces air downslope from the high plateau. The air warms as it descends
toward the California coast at the rate of 5 degrees F per 1000 feet due to
compressional heating. Thus, compressional heating provides the primary
source of warming. The air is dry since it originated in the desert, and it
dries out even more as it is heated.
Santa Ana winds commonly occur between October and February with December
having the highest frequency of events. Summer events are rare. Wind speeds
are typically north to east at 35 knots through and below passes and canyons
with gusts to 50 knots. Stronger Santa Ana winds can have gusts greater than
60 knots over widespread areas and gusts greater than 100 knots in favored
areas. Frequently, the strongest winds in the basin occur during the night
and morning hours due to the absence of a sea breeze. The sea breeze which
typically blows onshore daily, can moderate the Santa Ana winds during the
late morning and afternoon hours.
Santa Ana winds are an important forecast challenge because of the high fire
danger associated with them. Also, unusually high surf conditions on the
northeast side of the Channel Islands normally accompany a Santa Ana event.
Other hazards include: wind damage to property, turbulence and low-level
wind shear for aircraft, and high wind dangers for boaters.
An extremely verbose person is.........
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