Storm With Chance Of Tornado Barrels Toward SoCal: See Timeline For Its Arrival

As the most powerful storm of the season heads toward the Southland, residents, businesses and city officials race to prepare for wild weather with a chance of flooding, water spouts and even tornadoes.

The extensive cold-weather storm, expected to last for five days, has slowed its approach, stalling off the California Coastline much of Thursday, according to the National Weather Service. When it arrives, the storm promises to bring heavy rainfall, mountain snow in higher elevations, gusty winds, and possible mud and debris flows near burn-scarred areas.

Forecast models indicate that the storm will arrive in the Central Coast areas —specifically in Santa Barbara and Ventura Counties —on Thursday. The storm is expected to arrive early on Friday for the Los Angeles Basin and the Inland Empire, and Saturday in San Diego County, according to meteorologists.

Evacuation warnings have been issued from Thursday evening through Sunday mid-morning in burn scar areas and communities prone to flooding,

“This is a long-duration event,” Ryan Kittell, a meteorologist with the National Weather Service told The Los Angeles Times. “We expect many, many hours of widespread rain over the area.”

He said the longer the storm stalls along the coast, the more heavy moisture it could bring along with a slight chance of powerful wind gusts and a rare Southland tornado.

Rainfall is likely to intensify throughout Friday, with the bulk of the storm expected to settle in on Saturday. The storm could persist into early next week, through as late as Tuesday.

The timeline of the storm, according to NWS, varied across the Southland.

Los Angeles County

In the inland areas of Los Angeles County, showers and possibly a thunderstorm or two were possible on Friday, with 0.25 to 0.5 inches of rain likely, according to the weather service. Overnight, between Friday and Saturday, 1 and 2 inches of rain are possible. Showers and thunderstorms are expected to persist into Saturday, with an additional 1 to 2 inches of rain possible. The storm could linger until Tuesday night.

Closer to the coast, more rain is expected. Santa Monica and the Pacific Palisades area could see as much as 2 to 3 inches of rain overnight Friday, with an additional 1 to 2 inches of rain possible Saturday, according to the NWS. Residents living in Palisades Fire burn scar face potential evacuations amid downpours.

Inland Empire, San Gabriel Valley

The Inland Empire and San Gabriel Valley will see showers on Friday, with thunderstorms overnight, and periods of heavy rainfall on Friday night and Saturday. Rainfall of 1 to 2 inches is possible on Saturday, accompanied by gusty winds, according to the weather service. Showers are expected to linger through Tuesday night.

Southwest Riverside County and San Diego

Southwest Riverside and San Diego counties are expected to experience showers and thunderstorms on Friday, with forecasts for periods of heavy rain Saturday, and additional showers through Tuesday.

The National Weather Service initiated Flood Watches Saturday for Santa Barbara, Ventura, Los Angeles, San Bernardino, Riverside, Orange and San Diego Counties.

The Storm Path

Forecasters said the initial brunt of the storm will hit Santa Barbara County, then move into southern Ventura County later Thursday.

By the time it reaches Los Angeles County and the Inland Empire on Friday morning, "it will weaken but could still produce some isolated rain rates up to a quarter-inch per hour."

"Light to occasionally moderate showers will continue across Ventura and L.A. counties Friday afternoon into early Saturday morning ...," according to the National Weather Service.

Forecasters said heavy rain is set to arrive in the area Saturday morning. Though details remain unclear, that storm could result in a flood watch being extended across the county.

"With this in mind, residents, especially those in vulnerable areas, should start taking precautions immediately to prepare for the storm and protect their interests," forecasters said. "This scenario would potentially create many significant impacts area-wide, including possible debris flows in the burn areas, significant ponding of roads and highways, mudslides through the canyons, fallen trees, etc."

Evacuation Warnings For LA County Burn Scar Areas:

The city of Los Angeles issued an evacuation warning that'll be in effect from 6 p.m. Thursday through 11 a.m. Sunday for residents near the Palisades, Hurst and Sunset fire burn zones. County officials, meanwhile, issued an evacuation warning for residents near the Eaton Fire area in Altadena. County officials warned that any other recent burn area could also be at increased risk of flooding or debris flows.

The city of Los Angeles' Emergency Operations Center will activate at 6 p.m. Thursday, and the mayor's office stated that it will coordinate with the Emergency Management Department, Los Angeles Fire Department, Los Angeles Police Department, Los Angeles County Public Works and relevant city departments to keep residents safe.

The county is offering residents free sandbags for pickup at the Public Works Fleet Maintenance Yard, 252 Mountain View St. in Altadena, and at the Malibu Library parking lot, 23519 W. Civic Center Way.

In San Bernardino County, residents in burn scar areas were given sandbagging information, though no evacuation warnings had yet been given Thursday afternoon.

Across Riverside County, residents were reminded to use caution navigating across flooded roadways. A graphic image showed that 6 inches of flooded roads could sweep an adult off their feet; 12 inches of floodwater can sweep away a car, and 18 to 24 inches of floodwater can carry away SUVs, trucks and vans.

"With five days of rain headed to Southern California, with up to four inches expected in some areas, don't walk or drive through flooded roads," they said. "Turn around, don't drown."

Emergency Response Crews At The Ready:

Gov. Gavin Newsom said the state was pre-deploying emergency response crews in Los Angeles, Orange and Ventura counties to enable faster response to any storm-related issues that develop. He said 274 personnel were being deployed, along with 18 engines, three Urban Search & Rescue companies, six bulldozers, three swiftwater-rescue teams, three helicopters and five dispatchers.

In the Palisades Fire area, Caltrans will close Topanga Canyon Boulevard between Pacific Coast Highway and Grand View Drive at 10 p.m. Thursday. Caltrans officials said motorists should expect the stretch to remain closed at least through the Friday morning commute, but potentially through the weekend, depending how the storm develops.

That stretch of Topanga Canyon has been undergoing nightly repairs, with the road closed between midnight and 5 a.m.

There were no early reports of closed roadways in the Riverside County Idyllwild, Pass Area or the San Bernardino Mountains as of this report.

The National Weather Service urged homeowners across the Southland to prepare for the rain by ensuring gutters are cleared and windshield wipers are secure and working. They said people should consider rescheduling outdoor events, and advised motorists to avoid driving through flooded areas.