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

On Monday, another atmospheric river system is expected to arrive, leading to strong winds and heavier rains on Tuesday. —Nollyanne Delacruz, The Mercury News, 20 Dec. 2024

In Central and Southern California, the Great Basin and the Rockies, an atmospheric river event was set to bring rain and, in some places, snow. —Elizabeth Robinson, NBC News, 27 Nov. 2024

Pereira says the atmospheric river is likely to return to the region and could cause flash flooding and other headaches. —Kristin Wright, NPR, 28 Dec. 2024

Holiday travelers heading home this weekend could face severe weather in parts of the country, including an outbreak of tornados expected from the Southern Plains to the Southeast and an atmospheric river in the Northwest. —Jeanine Santucci, USA TODAY, 28 Dec. 2024

Word History

First Known Use

1993, in the meaning defined above