atmospheric river

noun

plural atmospheric rivers

: a concentrated band of water vapor that flows through the atmosphere and that is a significant part of the global hydrologic cycle and an important source of regional precipitation

Environment Canada is working on a new system to rank atmospheric rivers, a type of weather system that damaged highways, flooded farms and homes, and left at least four people dead in southern B.C. earlier this week.

—Wendy Stueck

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.

—National Oceanic and Atmospheric Administration

In a typical year, significant atmospheric river storms occur about 10 to 15 times in California. Ultimately, they account for up to 50% of the state's precipitation.

—Paul Rogers

Examples of atmospheric river in a Sentence

Recent Examples on the Web

But the second storm system, enhanced by an atmospheric river out of the southwest, could drop more than half an inch of rain west of the mountains and as much as 1 inch on Mount Laguna, forecasters said. —Gary Robbins, San Diego Union-Tribune, 13 Nov. 2023

When a series of atmospheric rivers flowed into California last January, the Big Sur coastline was quickly swamped, and Highway 1, a lone life raft connecting San Simeon in the south and the Monterey Peninsula to the north, was overcome. —Thomas Curwen, Los Angeles Times, 19 Nov. 2023

An atmospheric river is a plume of moisture that helps carry saturated air from the tropics to higher latitudes, delivering unrelenting rain or snow. —Ella Nilsen, CNN, 14 June 2023

Barely a year after dozens of powerful atmospheric rivers pounded the state and triggered historic flooding, state officials gathered at a muddy berm and pumping station near the Sacramento River this week to highlight the threat of flooding in a warming climate. —Jessica Garrison, Los Angeles Times, 24 Oct. 2023

The state was pummeled by many atmospheric river events in rapid succession last winter through early spring, which led the state to one of its wettest winters in history, according to data from NOAA. —Mary Gilbert, CNN, 19 Oct. 2023

This year’s soggy conditions were due primarily to 31 atmospheric river storms that unleashed torrents on the Golden State this winter and spring, as well as a very wet August marked by the rare arrival of Tropical Storm Hilary. —Hayley Smith, Los Angeles Times, 4 Oct. 2023

This past winter, the atmospheric rivers that pummeled California washed away many of the pups born at Piedras Blancas. —Sarah Kuta, Smithsonian Magazine, 3 Oct. 2023

An atmospheric river storm barreled into the Pacific Northwest on Sunday, bringing several days of heavy rain, likely ending the wildfire season in many areas and offering a bit of a reprieve for a region suffering extreme drought. —Evan Bush, NBC News, 25 Sep. 2023

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Word History

First Known Use

1993, in the meaning defined above