Mudslides Shut Down California Highway Amid Atmospheric River

Amid a new storm bringing mudslides and flooding, officials have shut down parts of the Pacific Coast highway as most of Southern California is under extreme rainfall and flood warnings.

"All lanes of PCH are closed just west of Corral Cyn in Malibu due to mudslides. No ETA at this time, avoid the area, use alternate route," the Los Angeles Sheriff's Department Lost Hills Station posted on X, formerly Twitter, on Wednesday.

Context

Heavy rains continued to hit much of California on Tuesday, just two weeks after atmospheric river storms devastated the region with severe flooding and mudslides.

Atmospheric rivers are corridors of tropical moisture that travel through the atmosphere. They transport this moisture from the equator toward the North and South poles, causing extreme weather like heavy rainfall and storms when they arrive.

As of Tuesday afternoon, downtown Los Angeles had received about 17.5 inches of rain since the water year began on October 1 and around 12 inches just during February.

What We Know

Parts of Southern California are under extreme rainfall and flood warnings as the weather phenomenon continues to make its way through the state. The atmospheric river is expected to cause extreme heavy rainfall, strong winds and heavy snow on the mountains. The extreme weather is expected to let up by Wednesday night.

Pacific Coast Highway in Malibu between Latigo Canyon and Corral Canyon is closed in both directions because of mud and rock slides.

Malibu Canyon Road was closed in both directions at Corral Canyon Road in Malibu due to a rockslide, according to the Los Angeles County Sheriff's Department. The closure was ordered at 5:50 a.m., the sheriff's department reported. It has reopened as of 7:30 a.m., but city officials are advising drivers to avoid it and beware of rocks and mud on the roads.

In addition. portions of the 101 Freeway from Seaward Avenue to California Street in Ventura are closed due to flooding and Highway 150 is also closed in both directions between Stonegate Road and Topa Lane because of slides and storm-related damage.

Views

Earlier this month, amid another storm hitting California, storm-chasing videographer Max Olson (@MesoMax919) posted dramatic footage on social media site X (formerly Twitter), captioning the clip: "Damaging mudflow in the Laurel Canyon area, we saw wood, and pieces of kitchenware flowing down earlier."

The 13-second video showed extremely fast-moving water gushing down the steep canyon road in Los Angeles, which had effectively created a river on what had been a regular street just shortly before. The water barreled past homes and cars parked on driveways, just feet away.

Meanwhile, Mengqian Lu, an associate professor at the Department of Civil and Environmental Engineering at the Hong Kong University of Science and Technology, previously told Newsweek there is data to suggest an increase in the number of atmospheric rivers, adding to extreme weather.

"Our projections, utilizing advanced data, suggest a marked increase in the frequency of atmospheric rivers along both the western and eastern coastlines of the USA."

What's Next?

There is evidence to suggest atmospheric rivers may be increasing. Recent research published in the Journal of Geophysical Research: Atmospheres found that atmospheric rivers could only increase if climate change continues to worsen.

The study used climate models to analyze how atmospheric rivers changed and will continue to change between 1980 and 2099 as global warming continues. The researchers found that rising surface temperatures will increase the moisture content in the air, subsequently forming more atmospheric rivers and the extreme weather that they often bring.

Update 2/21/24, 11 a.m. ET: This article was updated with additional information.

Update 2/21/24 11:48 a.m. ET: This article was updated with additional information.