The forecast of a dry winter is doing little to lower the blood pressure of foothill residents whose homes remain vulnerable to mudslides in the wake of the devastating Station fire.
That’s because a similar La Niña weather pattern last winter dropped uncharacteristically heavy rains, clogging local storm basins and sending mud flows into homes.
Caused by cooler-than-normal sea-surface temperatures in the Pacific Ocean, La Niña typically causes a colder, drier winter in the Southland, but that trend was bucked last year in February, when after weeks of heavy, inconsistent rains, earth left exposed by the Station fire in 2009 turned to mud and sloshed through homes in La Cañada Flintridge.
“Here in Southern California, after two weeks in December, my forecast was already busted,” said William Patzert, an oceanographer and climate forecaster at Jet Propulsion Laboratory. “Last winter is an example of where the statistics led us astray.”
While an average season delivers about 15 inches of rainfall locally, La Niña years generally result in 10 to 12 inches of rain. El Niño conditions, caused by warmer-than-normal sea temperatures, bring an average 18 to 20 inches.
According to records kept at Descanso Gardens, roughly 32 inches of rain were measured between Oct. 1, 2010, and Sept. 30 of this year.
Pat Anderson’s home at the top of Ocean View Avenue was heavily damaged in February 2010 when the Mullally debris basin above her property overflowed, sending debris and mud through her Paradise Valley neighborhood.
With her house still being rebuilt, Anderson said she has a lot riding on this season’s weather.
“Until my home is finished, even one heavy rainfall could cause heavy damage to my house,” she said. “So do I get nervous when I hear there’s going to be a significant amount of rain? Yes, I do.”
Despite the predictions of another La Nina weather pattern this winter, Anderson said she’d be watching the forecasts closely.
“I trust my sources, which are the Fire Department and the sheriff’s department,” she said, “but I just have to hope for the best, which is not a good position to be in.”
Chris Stone of the Los Angeles County Flood Control District said the debris basins serving the foothill area are at least 95% clear, and that channels and catch basins are clear and ready to receive any excess rainfall.
County officials are expecting this year’s rainy season to be similar to 2010-2011, he added.
“The weather patterns so far are very similar to what we had last year,” said Stone. “We expect short to longer periods of dry between the wet patterns.”
He noted that areas damaged by the Station fire are not expected to fully recover for another three years.
“We’re only two years of recovery after the Station fire, so there’s still a very high potential for debris flows coming off the burned watersheds,” Stone said. “There’s been lots of good growth, but there’s still lots of challenges remaining for this and next winter with debris flows."
-- Daniel Siegal, Times Community News
Photo: The sun sets during rush hour on the Ventura (134) Freeway near Glendale, as rain showers move through the area on Friday, November 4, 2011. Credit: Tim Berger/Times Community News.