Atmospheric River Brings Threat of Flooding, Mudslides

An atmospheric river storm has hit Southern California with record rainfall, bringing with it the threat of potential flooding and mudslides in wildfire-ravaged counties. Officials warn this storm could be the worst of the season with rainfall rates even higher than those that led to the deadly Jan. 9 mudslides. According to CBS News, record rainfall has been recorded in Santa Barbara, Palmdale and Oxnard at nearly 1.8 in.—an increase from the previous 1937 record of 1.3 in. The National Weather Service cautions that the worst of the storm could still be to come.

This particular storm is classified as an atmospheric river and a pineapple express storm. An atmospheric river storm is when long plumes of water vapor travel from the ocean and result in a heavy downpour, the Los Angeles Times explained. The further classification of a pineapple express is a particularly strong atmospheric river that bring in water vapor from the tropical Pacific Ocean.

Santa Barbara County officials have issued mandatory evacuation orders for 30,000 people and Los Angeles County also issued evacuation orders in high-risk areas, according to CNN. Already, mudslides and flooding have caused several road closures and blocked traffic.

“The Montecito event was largely the product of an extremely intense localized downpour,” said UCLA Climate Scientist Daniel Swain in relation to the Jan. 9 mudslides. “But the risk during this storm will extend across a much broader region, and there is a real possibility of major flash flooding and large debris flows and mudslides.”