Atmospheric river moves into SoCal, bringing heavy rain and raising risk of flooding: LIVE UPDATES

LOS ANGELES (KABC) — The first of two storms expected to batter the Southland began bearing down on the region Thursday, with significant rainfall and snowfall expected Thursday morning and well into the afternoon — ahead of more dramatic downpours anticipated early next week.

Drivers brace for rain-soaked commute

The Southland will likely see the brunt of the rainfall throughout morning rush hour, with the strongest downpours expected to occur during a one- to three-hour period “when the primary frontal band moves through,” according to the National Weather Service.

Forecasters predicted rain rates of about a half-inch per hour, with some localized areas receiving 0.8 inches per hour. Coastal and valley areas are expected to receive 1 to 2 inches of rain during the Thursday storm, with foothills and mountains potentially seeing 3 to 5 inches.

Heavy snowfall in Wrightwood

In Wrightwood early Thursday, the weather system was dumping significant snow amid powerful winds.

A winter storm warning was in effect and is scheduled to last until 10 p.m. Thursday in the eastern San Gabriel Mountains, including Mount Wilson, Mount Baldy, Wrightwood and the Angeles Crest Highway. As much as 18 inches of snow could fall above 7,000 feet in the area, with 6 inches possible at 6,000 feet and 3 inches at elevations as low as 4,500 feet. The snow will be accompanied by winds gusting at up to 55 mph, according to the NWS.

2nd storm on the way

The “Pineapple Express” – called that because its long plume of moisture stretched back across the Pacific to near Hawaii – will be followed by an even more powerful storm on Sunday, forecasters said.

The California Governor’s Office of Emergency Services activated its operations center and positioned personnel and equipment in areas most at risk from the weather.

Brian Ferguson, Cal OES deputy director of crisis communications, characterized the situation as “a significant threat to the safety of Californians” with concerns for impact over 10 to 14 days from the Oregon line to San Diego and from the coast up into the mountains.

“This really is a broad sweep of California that’s going to see threats over the coming week,” Ferguson said.

Last winter, California was battered by numerous drought-busting atmospheric rivers that unleashed extensive flooding, big waves that hammered shoreline communities and extraordinary snowfall that crushed buildings. More than 20 people died.

The second storm in the series has the potential to be much stronger, said Daniel Swain a climate scientist at the University of California, Los Angeles.

Models suggest it could intensify as it approaches the coast of California, a process called bombogenesis in which a spinning low-pressure system rapidly deepens, Swain said in an online briefing Tuesday. The process is popularly called a bomb cyclone.

The new storms come halfway through a winter very different than a year ago.

Despite storms like a Jan. 22 deluge that spawned damaging flash floods in San Diego, the overall trend has been drier. The Sierra Nevada snowpack that normally supplies about 30% of California’s water is only about half of its average to date, state officials said Tuesday.