A string of winter storms will drop rain on the Los Angeles area and bring snow to the mountains this week, forecasters say, raising concerns about debris flows in recent burn areas.
The heaviest precipitation was expected Tuesday night into Thursday. That system will connect to an atmospheric river, a stream of high-moisture-content air that creates a sort of pipeline of water, and dump 2 to 3 inches of rain over much of L.A. County, said Kathy Hoxsie, a meteorologist with the National Weather Service in Oxnard.
A weaker round of rain and snow was also forecast to hit Monday morning.
That comes after the first in the series of storms sprinkled up to half an inch of rain over the area Saturday into Sunday.
Snowfall ranged from a dusting along the Grapevine to as much as 2 inches at higher elevations. In Malibu, residents shared social media images of impromptu sledding sessions, a rarity for the coastal area. But what looked like snow there was actually small-pellet hail, Hoxsie said.
That didn't stop some drivers from pulling over to frolic in the foreign whiteness.
Officer Stephan Brandt of the California Highway Patrol said his department had received a report shortly after 5 p.m. Saturday of multiple drivers stopping and parking near the Malibu Canyon Tunnel.
“They were playing in the snow,” said Brandt, who advised such activities were “dangerous” and unwise.
The next storm was expected to move into the Central Coast on Sunday evening and reach the Los Angeles area by Monday morning, Hoxsie said.
“It will be a little wetter and a little colder,” she said.
Snow levels were expected to drop as low as 1,500 feet, with 1 to 3 inches in the Antelope Valley foothills and a dusting possible in the Santa Clarita Valley. Forecasters were calling for 2 to 4 inches of snow along mountain passes and up to 8 inches at higher elevations.
Strong winds were expected along the coast in L.A. and Ventura counties, with gusts of 40 to 50 mph, and in the Antelope Valley, with gusts potentially exceeding 60 mph.
Forecasters were calling for large surf, with waves of 8 to 12 feet on west-facing beaches Monday and Tuesday. “So nobody should be out in the water,” Hoxsie said.
During the third storm, expected to be even colder and wetter, rainfall rates could be high at times, raising the possibility of debris flows in recent burn areas, as well as mud and rockslides on mountain roads. Significant snow accumulation is possible, mainly above 5,000 feet.
A fourth storm system is possible starting Saturday.
The pattern change was coming after a summer that featured record heat, the worst fire season in California history, and a dry fall and early winter when Southern California was raked by Santa Ana winds.
Though the Pacific Northwest and northern Intermountain West have enjoyed heavy precipitation from a series of northern Pacific storms, the central and southern parts of the West are in drought that’s about as bad as it can get.
This round of rainfall probably still won’t be enough to bring the area to normal levels for the season, Hoxsie said.
“We started so dry that this is not enough,” she said. “If it shuts off after these storms, we’ll probably still be in trouble.”
Times staff writer Paul Duginski contributed to this report.
This story originally appeared in Los Angeles Times.