What exactly is an Atmospheric River? – USGS Communication

Atmospheric rivers occur all over the world in this global view from February, 2017 (courtesy of NASA | Goddard Space Flight Center Visualization Studio).

Atmospheric rivers have been in the news a lot over the past couple of months, from a late October atmospheric river that brought record-breaking rainfall across Northern California to a mid-November storm that led to catastrophic flooding in Washington. A new atmospheric river storm is hitting the Western U.S. now and more are likely on their way. But what exactly is an atmospheric river?

Rivers in the Sky

A powerful storm formed above the Pacific Ocean battering the U.S. West Coast seen by a weather satellite in January 2023. (image courtesy of Cooperative Institute for Research in the Atmosphere - CIRA - between Colorado State University and NOAA via Space.com).

Atmospheric rivers are relatively long, narrow regions in the atmosphere – like rivers in the sky – that transport most of the water vapor outside of the tropics. These columns of vapor move with the weather, carrying an amount of water vapor roughly equivalent to the average flow of water at the mouth of the Mississippi River. When the atmospheric rivers make landfall, they often release this water vapor in the form of rain or snow…

California faces weeks of cleanup as “one last” major storm lashes state – Axios

Nutan Mellegers, far right, has cheerful cohort of friends pitch in to help cleanup her Sylvan Way home in Felton Grove between downpours on Tuesday © 2023 Shmuel Thaler - Santa Cruz Sentinel.

California was lashed by the final in a series of lethal atmospheric rivers Monday night — as officials warned it could take weeks to clean up the sustained heavy rains, snow and floods that’ve hit the state.

The latest: A mandatory evacuation order was issued for a flooded mobile home park in Acampo after 175 residents left voluntarily earlier Monday, per the San Joaquin County Sheriff’s Office…