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

If eastern atmospheric rivers are generally juicier, why aren’t historic flooding events happening constantly? —Mary Gilbert, CNN Money, 18 Apr. 2025

While atmospheric rivers are essential to replenishing California's water supply, their unpredictability and intensity pose challenges for flood control and public safety. —David Faris, MSNBC Newsweek, 11 Apr. 2025

But in wet years, when big atmospheric river storms come off the Pacific, warmer conditions can cause more water to evaporate into those systems, bringing more rain. —Paul Rogers, Mercury News, 1 Apr. 2025

The big picture: California's rainy season, which roughly spans from November to early April, is marked by the prevalence of atmospheric rivers, characterized as highways of concentrated water vapor that travel across the Pacific Ocean which dump heavy snow or rain on land. —Nadia Lopez, Axios, 12 Mar. 2025

Word History

First Known Use

1993, in the meaning defined above

Rhymes for atmospheric river

• caregiver
• deliver
• downriver
• lawgiver
• upriver
• giver
• liver
• livre
• quiver
• shiver
• sliver