Atmospheric river storms have wreaked havoc on the West Coast, and are getting bigger. These scientists chase them in the sky to predict where they will strike. In January 2024, Anna Wilson was ...

Forecasters predict the atmospheric river will continue to focus across Southern California over the next 12 to 24 hours, maintaining a significant threat for life-threatening flash flooding. Qian ...

Caltrans crews work to clear a mudslide on Highway 17 that resulted from heavy rain from an atmospheric river storm in the Santa Cruz Mountains, south of Glenwood Drive in Scott's Valley, Calif ...

AP Photo/Damian Dovarganes, File Mud and debris is strewn on Fryman Road during an atmospheric river Feb. 5, 2024, in Studio City, California. AP Photo/Marcio Jose Sanchez, File ...

An atmospheric river can be thousands of miles long and hundreds of miles wide, and carries moist air from tropical regions and dumps it across another, bringing with it heavy rain and snow.

WHERE DID THE TERM ATMOSPHERIC RIVER COME FROM? The name came from research published in the 1990s by scientists Yong Zhu and Reginald E. Newell of the Massachusetts Institute of Technology.

Last year, more than 20 people died in the state from similar damaging atmospheric river storms. It also caused $4.6bn (£3.6bn) in damage, according to CBS News, the BBC's US partner.

Forty-six atmospheric rivers made landfall on the U.S. West Coast during water year 2023, according to the Scripps Institution of Oceanography’s Center for Western Weather and Water Extremes.

Known as "rivers in the sky", atmospheric rivers are ribbons of water vapour. Each can be several hundreds of kilometres wide, and transport 27 times as much water as the Mississippi River.