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

An atmospheric river is currently bringing excessive moisture to the Pacific Northwest, including as much as 7 inches of rain to parts of Washington, and another is on the way before Christmas. —Thomas G. Moukawsher, Newsweek, 16 Dec. 2024

The atmospheric river feeding the system will tap into the warm tropical ocean off the coast of the Southeast to create moisture levels rarely seen in the Northeast outside of tropical systems, allowing for faster rainfall rates and the potential for flash flooding. —Elisa Raffa, CNN, 10 Dec. 2024

The atmospheric river roared into the Northwest last week, slamming Washington and Oregon and sweeping down to Northern California, bringing high winds and torrential rain. —Bill Hutchinson, ABC News, 24 Nov. 2024

California atmospheric river brings record rain, major mudslide risk. —Andrew J. Campa, Los Angeles Times, 24 Nov. 2024

Word History

First Known Use

1993, in the meaning defined above