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 Pacific Northwest, including Washington, Oregon, and Northern California, may see multiple atmospheric river events, which could bring beneficial moisture but also increase risks of flooding and landslides, especially in areas with steep terrain. —Jim Foerster, Forbes, 30 Oct. 2024

So a map of actual 1,000-year rainstorms would show clusters reflecting hurricanes along the East Coast, atmospheric rivers along the West Coast, and thunderstorm complexes in the Great Plains, where thunderstorm systems form. —Russ Schumacher, Discover Magazine, 8 Oct. 2024

The snow lines are rising even higher than that when comparing snow associated with atmospheric rivers to other snow events, Gershunov told USA TODAY on Monday. —Christopher Cann, USA TODAY, 4 Mar. 2024

Researchers are looking into whether an atmospheric river also contributed to the heavy precipitation, Shepherd said. —Julia Jacobo, ABC News, 3 Oct. 2024

Word History

First Known Use

1993, in the meaning defined above