A series of storms is heading to Southern California and is expected to dump the heaviest rainfall since last summer's Station fire and send debris and ash rushing into such foothill communities as La Cañada Flintridge and La Crescenta.
"This is their worst nightmare," said Bill Patzert, a climatologist with the Jet Propulsion Laboratory in La Cañada Flintridge. "It will be unrelenting."
Four storms are expected to move through the region between late Sunday and Friday, dropping 4 to 8 inches of rain in the coastal and valley areas, and 8 to 16 inches in the foothills and mountains, according to the National Weather Service.
Surfers will be thrilled with large swells and skiers will be able to carve through a layer of fresh powder on the mountains, but coastal residents could see flooding in beach areas that will also be inundated with urban runoff. The greatest concern are the communities beneath the Angeles National Forest hillsides left barren by the Station fire, which burned more than 160,000 acres.
The county's mudslide preparedness in the burn areas has been tested this winter, but not in such a quick succession of storms, said Bob Spencer, spokesman for the Los Angeles County Department of Public Works.
Four "storms back to back, that's a little bit more worrisome for us. By all accounts, it's going to be the biggest so far," he said. "We're ready for it. We've done everything we can do."
More than 100,000 feet of concrete K-rail barriers have been laid to divert mudflow and debris away from homes, and 28 debris basins have been emptied and are ready to collect mud and rocks.
County officials plan to close mountain thoroughfares, including Angeles Forest Highway, Big Tujunga Canyon Road and Upper Big Tujunga Canyon Road, at 4 a.m. Sunday. The roads will reopen after the storm systems pass. Dozens of residents who live in mountain hamlets accessible by the roads have been urged to evacuate.
Officials with the public works, sheriff's and fire departments and other involved parties will hold a conference call this morning to analyze the latest meteorological forecasts and mudslide predictions. All will have personnel on scene throughout the week.
Residents are being urged to closely monitor weather reports and prepare to evacuate.
"If they see debris coming down their streets, we strongly recommend they just evacuate, they just get out of the area, get in their vehicle, come down the hill and wait till it's over," Spencer said.
The message has become second nature for many members of the affected communities.
"The suitcases are ready, the animals are ready," said Genevieve McLoud, who has lived in the 5900 block of Canyonside Road in La Crescenta for three decades. "We are parking across the street, all prepared to get out of here as quick as we can if we have to."
These preparations are growing increasingly routine for residents, who will have to deal with the mudslide danger for several years until the hillsides are stabilized by vegetation.
"Even now, there is greenery appearing at the ground level. It's amazing how quickly the ecosystem recovers from this," Spencer said. "But any legitimate growth that may hold some of this debris, the forest experts are telling us [takes] between five and seven years."