Light to moderate rain is expected, off and on, for the rest of this week and early next week, increasing the chances of mud and rock slides in already sodden Southern California, forecasters said Monday.
"It's shaping up as a gloomy week," the National Weather Service said.
A low-pressure system will continue to spin periods of rain into Southern California beginning today and lasting into the weekend, the weather service said.
Computer models are indicating a potentially stronger storm late Sunday and Monday.
Forecasters don't expect any extended periods of heavy rain.
"However, with the ground already saturated from a very wet January, it will not take much more rain to cause additional problems, including rock and mud slides," the weather service said.
In downtown Los Angeles, total rainfall for the season, which began July 1, stands at 25.16 inches, almost three times the normal total for the date and more than six times the total that had fallen by this time last year.
On Jan. 10, a massive mudslide buried part of the Ventura County coastal community of La Conchita, killing 10 people. Lesser slides have destroyed homes in Orange County and cut off dozens of roads in Southland hills and canyons.
Forecasters said a large Pacific storm system should start moving inland across Ventura, Los Angeles and Orange counties this morning, with showers in the Los Angeles area by late afternoon.
There will be breaks in the rainfall, the weather service said. The best chances for measurable rain will be this afternoon or evening through Wednesday afternoon and again Thursday afternoon through Saturday. A total of up to 3 inches of rain is possible in the coastal valleys by Saturday night, with up to 6 inches in the foothills and mountains.
A small break is then expected until Monday. But the rain next week could be heavier, forecasters said.
The first storm will be relatively warm, with snow levels starting about 8,000 feet. Colder air will move in by Thursday night, with as much as 2 feet of new snow above 6,000 feet by Saturday night.
More snow is expected at mountain resort levels next week.