Los Angeles County can expect to see rain across the region beginning Sunday night and continuing through Wednesday, with the latest winter storm system forecast to bring the heaviest rain and threat of flooding along the Central Coast.
Compared with the historic storm that pummeled the region earlier this month, forecasters expect “much less rain” for the county this time but warned that the most intense precipitation will hit during the day Monday and Tuesday night. Over the next three days, downtown could see up to 2.4 inches of rain; Santa Clarita, 2.19 inches; Long Beach, 1.8 inches; and Torrance, 1.97 inches.
The rain may not be as intense as some areas farther north, but there are still concerns about the prospect for flooding, landslides and mudflows — particularly in the Santa Monica Mountains and Hollywood Hills — because of the soaking Southern California received from the previous storm, David Gomberg, a weather service meteorologist in Oxnard, said during an online media briefing Sunday afternoon.
A flood watch was in effect across broad swaths of California.
“Debris flows, mudslides, and landslides could happen just about anywhere within the flood watch area, as even L.A. County — which is expecting somewhat lower rainfall totals — took the brunt of the last storm, leaving them more susceptible to this kind of activity,” the weather service office in Oxnard said Sunday night.
Residents are urged to move parked cars out of low-lying flood-prone areas, to be alert for mudslides and rock slides on or below canyon roads and to prepare for possible flooding and power outages, the weather service said.
The slow-moving storm system began moving into the Central Coast region Saturday night, bringing light rain to Santa Barbara and western San Luis Obispo counties, officials said. The second, more powerful wave of the storm had arrived in Santa Barbara by Sunday evening. Officials warned of gusty winds, an increased chance of thunderstorms, and the possibility of high surf and coastal flooding.
By 8:20 p.m. Sunday, forecasters reported rainfall rates of between 0.3 to 0.5 inches per hour across the Santa Barbara area.
The Central Coast is expected to feel the brunt of this storm, according to the weather service. Santa Barbara and San Luis Obispo county foothills and mountain ranges could see 8 to 10 inches of rainfall. The city of Ventura can expect to see up to 3.01 inches, and the city of Santa Barbara 5.66 inches.
High surf advisories are in effect through Tuesday across all beaches in the region, with waves of up to 20 feet expected in some areas. Strong rip currents are expected with large breaking waves at Morro Bay, Port San Luis and Ventura harbors.
There is also a brief risk of “weak tornado activity” during this period in San Luis Obispo County, Gomberg said Sunday.
The greatest threat for coastal flooding — particularly in Malibu and Santa Barbara — will be Tuesday morning, Gomberg said.
The engine driving the storm system across the central Pacific is the jet stream — high-altitude winds in excess of 200 mph — which is expected to slow as it approaches the coast.
Once the system has passed, the state will have a few days to wring itself out before the arrival of another possible system next weekend, Gomberg said, this time coming out of the north and potentially colder.
Times staff writer Thomas Curwen contributed to this report.