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.