The second of two cold fronts to sweep Southern California will hit the Los Angeles area Saturday, bringing  rain, possible thunderstorms and the threat of mud and debris flows in hillside areas scorched by last year’s wildfires, according to the National Weather service.

Rains on Friday snarled traffic and prompted road closures in foothill communities bordering the Angles National Forest, where more than 160,000 acres were charred in the Station fire. Rains in Los Angeles County were relatively light Friday, but Orange and San Diego counties experienced heavy thunderstorms and 45 mph wind gusts along the coast.

Forecasters predict up to 1½ inches of rainfall across the coastal and valley areas with as much as 3½ inches in the foothills and mountains.

A flash flood watch was put in effect for portions of Los Angeles, Ventura and Santa Barbara counties on Friday and will remain in place through Saturday, according to Jamie Meier, a meteorologist at the National Weather Service in Oxnard.

Mountain resort areas can expect between a foot and 20 inches of snow at levels of 6,000 feet to 7,000 feet, dropping on Saturday to about 4,500 feet to 5,000 feet, just below the Grapevine on Interstate 5, Meier said.

It should also be quite windy, with mountain regions experiencing 20- to 30-mph winds and gusts up to 55 mph, Meier said.

Temperatures were not expected to rise above the low 60s, with overnight lows in the lower 50s through the weekend, she said.

Another storm could dampen the county Tuesday and Wednesday, Meier said. If it materializes as predicted, that storm is expected to produce less than an inch of rain to the county.

The county’s environmental health division is advising people to stay out of the ocean along coastal beaches until three days after the rain stops because of the possibility storm runoff could bring disease-carrying bacteria into coastal waters.

Strong El Niño conditions expected to last through this spring could contribute to above average rainfall in the southern United States, according to forecasts from the National Oceanic and Atmospheric Administration.

While forecasters can’t attribute particular storms directly to El Niño, the recent wet weather in our region fits the typical pattern for the climatic phenomenon, Meier said.