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

Farther west, a low-pressure weather system tied to the ongoing atmospheric river continued to shift inward from coastal areas, bringing with it rain and snow. —Emily Mae Czachor, CBS News, 26 Nov. 2024

Georgia governor signs bill that would define antisemitism in state law First of back-to-back atmospheric rivers pushes into California. —San Diego Union-Tribune, 25 Nov. 2024

The rain is expected to be heavier in the North Bay, though not as heavy as when the atmospheric river first arrived in the middle of last week. —Rick Hurd, The Mercury News, 25 Nov. 2024

Bomb cyclone to enhance powerful atmospheric river targeting West Coast Two people were killed by falling trees in Washington state. —Bill Hutchinson, ABC News, 24 Nov. 2024

Word History

First Known Use

1993, in the meaning defined above