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

The Blue Nile has almost run dry, starved of the rains at its source that were historically sustained by atmospheric rivers flowing from the Congo Basin rainforests. —Erin Prater, Fortune, 24 Sep. 2024

This February, an atmospheric river dumped record amounts of rain across southern California, triggering hundreds of mudslides and leaving at least nine people dead. —Laura Paddison, CNN, 7 Sep. 2024

In winter, however, the North Pacific High tends to weaken and shift south, allowing atmospheric rivers to reach the state. —Ned Kleiner, Los Angeles Times, 17 Aug. 2024

With the atmospheric rivers hitting California earlier this month, the zoo's crew thought a performance might be in the works. —Mike Snider, USA TODAY, 25 June 2024

Word History

First Known Use

1993, in the meaning defined above