Hello Everyone,
This comes from the SoCalFire Yahoo group. During the fire season, this groups is well known for its excellent coverage [scanner frequencies, fire maps and actual posts from firefighters on the job] of any given wildfire[s], south of San Luis Obispo.
The "snip" below comes from an L.A. Times article that endeavors to explain why certain area in L.A and environs experience fires while other areas in the local do not. Thought it might be of interest to you.
Have a wonderful Easter!
Alan...N6HPO...Valley Center
<http://www.latimes. com/news/ local/la- me-firemaps2- 2010apr02, 0,3300941. story>
Hot, dry Santa Anas a particular threat in some Southern California areas
By Bettina Boxall
April 2, 2010
Why does Malibu seem to erupt in flames every fall, while most of Los Angeles, which has its share of houses clinging to brushy hillsides, does not?
The reason, according to a new study, is blowing in the wind.
Researchers have developed the first high-resolution map of Santa Ana wind events, showing that the hot, dry blasts don't sweep uniformly across the Southland and that the danger of large, wind-whipped wildfires is therefore greater in some parts of the region than others.
Wind corridors graphic: http://tinyurl. com/santa- ana-corridors
"We have some of the most amazingly dangerous fire weather on the planet," Moritz said. "You could use a model like this to help make decisions about where and when you might want to restrict access so you don't get ignitions in the worst possible places at the worst possible times." <snip>
Certain mountain passes, especially Soledad, Cajon and San Gorgonio, act as funnels for the gusts, which heat up and gain speed as they are drawn from the interior West to the Pacific Coast by differences in atmospheric pressure.
Guided by local topography, the seasonal Santa Ana's follow certain corridors to the sea, consistently skirting other areas.
"Most people, think, 'Ah, it's a Santa Ana day, Southern California is in trouble,' and that is true," said Max Moritz, the study's lead author and co-director of the UC Berkeley Center for Fire Research and Outreach. "But there is much more spatial difference in that story, much more diversity."
The paper, published February in the online version of Geophysical Research Letters, includes a map marked with distinct bands outlining the favored Santa Ana routes.
"The Santa Monica Mountains and the Malibu area are just hammered," Moritz said. "Then the whole L.A. Basin to the south of there is actually in a sheltered window. You go farther south and you get another big band of high fire danger" in the Laguna Hills area of Orange County and then another in eastern San Diego County.
Pinpointing which parts of Southern California are the hardest hit carries implications for development, building standards, public lands management and property insurance.