By Hector Becerra, Los Angeles Times Staff Writer
1:39 PM PDT, October 21, 2007
The fires burning across Southern California today are being fueled by unusual hurricane-force Santa Ana winds that topped 100 mph, and forecasters say the winds and heat will worsen in the coming days.
At Whitaker Peak, elevation 4,100 feet, gusts were clocked at 108 mph. The measurement on the isolated, tumultuous peak spoke to the strength of the winds hammering Southern California.
"The strongest winds have not occurred yet. They're going to peak [on Monday]," said Ken Clark, a Rancho Cucamonga-based expert senior meteorologist for Accuweather.com. "This is not just any strong event. This is one of the strongest events you get during any Santa Ana season."
In the Newhall Pass and in Port Hueneme, winds gusted up to 78 mph Sunday, qualifying as hurricane force gusts. Generally, gusts were measured between 30 mph to 60 mph, including in Malibu and the major wildfire areas.
Early last week, weather experts were already bracing for a buffed-up Santa Ana event. A strong high pressure system was brewing above the Great Basin area over Utah, paving the way for Santa Anas to come barreling down to the lower elevations of Southern California, said Kenneth Reeves, director of forecasting for Accuweather.com, a private forecasting firm.
"You could see the difference just in the last three to four hours," Reeves said Sunday morning. "The relative humidity went from 60 to 70 percent around dawn to single digits: five, seven, eight percent. It's a classic example of drier air combined with wind to really cause some problems."
Reeves said while top wind speeds were measured in relatively isolated areas, like the top of mountains, they were "disconcerting" because those same gusts funneled to lower elevations--albeit at somewhat reduced speeds.
"If you go to any mountain range, like the Rockies, even as far as the top of volcanoes in Hawaii, the difference in winds is noticeable, but they aren't racing at 100 miles per hour," Reeves said. "When you see reporters covering a hurricane, it looks like they're being pushed around pretty hard. More often than not ... the winds are about 40 miles per hour. And you can see what that's doing to them."
In Fremont Canyon in the Santa Ana mountains, southeast of Yorba Linda, gusts reached 86 mph.
"You get light Santa Anas to extremely strong Santa Anas. This is going to be at the top end," said Ken Clark, a Rancho Cucamonga-based senior meteorologist for Accuweather.com.
"Everything is coming together for an exceptional wind event. And this is going to drive humidity to exceptionally low levels."
Making things worse, the temperatures in Southern California are expected to get warmer in the next few days. Temperatures in downtown Los Angeles are expected to reach into the 90s on Tuesday, possibly hitting the record for that day: 98.
"It's a combination of everything you can imagine getting together to make things real bad," Clark said.
December and January are actually busier months for Santa Ana events. And forecasters are warning that signs are pointing to a developing, strong La Nina in the Pacific Ocean. That climate pattern is associated with drier than normal winters in Southern California. That's bad news for a region that has just experienced it's driest season in more than a century.
"We're not only going into a La Nina. We're in La Nina, and it's an increasing La Nina," Clark said. "It's intensifying. And that doesn't bode well. When you talk about one year of drought, Southern California can handle that. But two in a row, especially coming after a record year, can cause real problems. In terms of the wildfire situation, it obviously doesn't bode well."
Weather experts said the Santa Ana winds were expected to remain strong through Tuesday afternoon at least.
hector.becerra@latimes.com
