Hurricane-Like Winds Wreak Havoc on Southern California

A Western Catalpa at the L.A. County Arboretum was one of 300 trees that succumbed to the Dec. 1, 2011 hurricane-like Santa Winds, the strongest winds in decades. The Arboretum has launched a tree fund to replace the destroyed trees and shrubs, the single largest tree planting campaign in its history. The Arboretum believes it will take ''several years'' to replace the damaged landscape.

 

December roared into California and other southwestern states when unusually strong Santa Ana winds exhibited gusts on the level of Hurricane Irene winds.

Southern California typically experiences Santa Ana winds in the fall and winter. They are normally warm, dry winds, but in this case they were cold and dry.

This Santa Ana wind event, according to the National Weather Service, was created by an extreme pressure change between the Northwest and Southwest regions. A strong high-pressure system in the Northwest met a low-pressure system in the Southwest, creating a ''pressure gradient that drove winds over mountains and through the California canyons.''

Southern California mountain passes had gusts of 80 mph. Near Sacramento in northern California, there were gusts up to 40 mph, and 100 mph gusts at higher elevations, reported National Weather Service meteorologist Bill Rasch.

LASN magazine is headquartered in Tustin, Calif., just south of the cities of Santa Ana and Anaheim. The winds were strong here, but the most damaging winds were northeast of us in Los Angeles County's San Gabriel Valley. About 30 homes were damaged in Temple City, up to 200 trees toppled and 75 percent of the city lost power. Other San Gabriel Valley cities hit hard were Alhambra, South Pasadena, Pasadena, San Marino, San Gabriel, Sierra Madre, Monrovia, Glendora and Arcadia.

Out at the L.A. County Arboretum, the staff estimates some 300 trees destroyed. Some species, like the Engelmann oaks and 150-foot tall Mexican fan palms endured the winds with little damage, but stiffer species, such as the Elephantine ficus, snapped. The dry conditions, however, helped keep many trees from uprooting.