Weather balloons and “hurricane hunter” planes aid the science of understanding California’s atmospheric rivers.

An expert at the Scripps Institution of Oceanography explains the weather phenomenon that can wreak havoc across California.

Part of the Atmospheric River Reconnaissance program ... the program also involves launching radiosondes from airplanes called “hurricane hunters,” flown over the ocean by National Oceanic ...

As heavy rain from a large storm subsided, officials in Southern California said rock and mudslides remain a threat.

The San Juan Creek in California was flowing uncontrollably on Friday after an atmospheric rain that hit Southern California on Thursday.

The atmospheric river also brought several feet of snow and hurricane-force winds to the California mountains and West. Crews began clearing affected roadways, including the Pacific Coast Highway ...