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

Forecasters at the National Weather Service (NWS) Weather Prediction Center are anticipating that four-day rainfall records could be broken this week in eight cities as an atmospheric river pummels the U.S. with heavy rain. —Lee Habeeb, MSNBC Newsweek, 3 Apr. 2025

In general, atmospheric rivers pick up water vapor from the warm, moist air of tropical regions and then drop the water over land in cooler regions as rain or snow. —Christopher Cann, USA Today, 3 Apr. 2025

Last month, scientists launched special weather balloons to study atmospheric rivers in the western U.S. —Marshall Shepherd, Forbes, 21 Mar. 2025

For example, in Southern California, atmospheric rivers accounted for as little as 5% of precipitation in 1977 and as much as 71% in 1956, scientists say. —Ashley MacKin Solomon, San Diego Union-Tribune, 7 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