LOS ANGELES (CNS) - A storm out of the Pacific Northwest headed toward the Southland today, packing the potential to generate showers, snowfall as low as 3,500 feet, and hazardous travel conditions on roads in or near the San Gabriel mountains, forecasters said.

Interstate 5 and the Antelope Valley (14) Freeway appeared particularly vulnerable, with blowing snow and icy conditions expected by Sunday, they said.

Additionally, they added, there is a possibility of thunderstorms, which could trigger debris flows over slopes denuded by wildfires.

“A cold low-pressure system will move into the area late Friday and persist through Monday,” bringing the potential for low snow levels and a slight chance for thunderstorms on Saturday afternoon through Sunday evening, according to National Weather Service statements.

But as of Thursday, the expected winter conditions were “just a possibility — not a certainty,” said one NWS statement.

The NWS issued a winter storm watch for the San Gabriels from Saturday afternoon through Monday afternoon because of the possibility of snow, blowing snow, lightning and poor visibility — a quarter-mile or less. It said between eight and 16 inches snow could accumulate above 5,500 feet by Monday morning — less above 4,000 feet.

People planning to travel through the San Gabriels were urged to pack an emergency kit containing a flashlight, food, water, blankets, extra clothing and tire chains.

Temperatures, meanwhile, will remain mainly in the 60s for several days, with a slight warming trend beginning Thursday in some communities.

The NWS forecast highs today of 54 on Mount Wilson; 62 in San Clemente; 64 in Palmdale, Lancaster, Avalon and at LAX; 66 in San Gabriel, Saugus, Newport Beach, Mission Viejo and Laguna Beach; ; 67 in Long Beach, Pasadena, Burbank and Fullerton; 68 in downtown L.A., Anaheim, Yorba Linda and Irvine; and 69 in Woodland Hills.

The forecast calls for showers through Monday.