Residents and authorities in Southern California foothill communities are bracing for pounding rain, flooding, mudslides and debris flows that could begin in the wee hours of Friday morning.

“It’s coming,” said Bonnie Bartling, weather specialist for the National Weather Service, adding that rain could start falling as early as 10 p.m., with the heaviest deluge expected around 3 or 4 a.m.

Up to 1,000 homes in the area affected by the Colby fire in Azusa and Glendora are under a mandatory evacuation order amid fears that mud and debris could inundate their homes. The Glendora Police Department urged residents to leave, warning that they faced “injury and/or death.”

On Ridge View Road, many residents evacuated, but others prepared to defend their homes. Tony Ramirez, 71,  and his son picked up two truckloads of sandbags Wednesday night. He was up at 5 a.m. Thursday and headed to Home Depot to buy plywood. Then he built barriers to try to channel mud and water away from his home.

After that, it was time for a grocery run: Bread, fruit and two containers of Ben & Jerry’s “Cherry Garcia” ice cream.

“I got four one-gallon jugs of white wine in the garage,” he added. “I don’t know if it’s good.”

Ramirez said that if he and his dog, Cookie, cannot wait out the storm with his supplies, he parked his truck nearby just in case he needs to escape.

In Glendora, residents north of Sierra Madre Avenue between Yucca Ridge Road and Glendora Mountain Road must evacuate. In Azusa, the order applies to residents on Ridge View Drive. Both areas are situated below the Colby fire burn area, which denuded hillsides of rock- and dirt-holding vegetation.

In January, the wildfire burned 1,900 acres and destroyed five homes and damaged seven others.

Residents like Susan Paulus remember all too well the destruction that can be caused by flowing debris. She recalled the massive mudslides of 1969 that came after a wildfire the year before. The flows destroyed 200 homes and killed 34 people.

"When I was young, it was towels under the doors," she said as crews around her off-loaded concrete barriers known as K-rails along the curb. "In '69, they weren't ready for it."

This time, however, city officials are hoping for a different outcome.

Workers have been erecting K-rails to direct the flow of any mud and debris that comes down from the burn area. In Glendora, the vulnerable area is a roughly three-mile stretch from the city's western border to Loraine Avenue, encompassing about 1,000 homes.

In the Colby fire, some residents ignored warnings and stayed behind to try to beat back flames. But Police Chief Tim Staab urged residents to heed the evacuation orders issued Thursday.

“I understand that when there’s fires, you want to stay behind to try and fight it with a hose,” he said. “However, with mudflow, there’s just nothing you can do. And you put yourself in danger.... It may sound overly cautious on our part, but we just want to make sure everyone’s safe.”

The stronger of two storms is expected to bring the potential for heavy rain through Saturday, with 1 to 3 inches in the coasts and valleys and 3 to 6 inches in the foothills and mountains. Forecasters say thunderstorms are also possible, with damaging winds, small hail and even weak tornadoes possible.

The Los Angeles County Sheriff’s Department closed roads in and around the Angeles National Forest, including Old San Gabriel Canyon Road from the Azusa City boundary to the national forest.

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