atmospheric river

American  

[at-muhs-fer-ik riv-er, -feer-] / ˌæt məsˈfɛr ɪk ˈrɪv ər, -ˈfɪər- /

noun

Meteorology.

1. a long, narrow corridor in the atmosphere that transports massive amounts of concentrated water vapor from the tropics: often responsible for extratropical cyclones and other extreme weather events, but also for commonly weaker systems of rain that replenish water supplies. AR

---

Etymology

Origin of atmospheric river

First recorded in 1990–95

Example Sentences

By late April, temperatures had begun to rise, but reports indicated that unsettled, wet conditions were still on the way for Southcentral and Southeast Alaska as an atmospheric river approached.

From Science Daily • May 6, 2026

That comes after a series of atmospheric river storms resulted in downtown Los Angeles’ wettest start to the water year, which begins Oct. 1., since 2011.

From Los Angeles Times • Jan. 22, 2026

Heavy rain from an atmospheric river system caused flooding and mudslides, particularly in areas still scarred by wildfires.

From Salon • Dec. 27, 2025

Which is why water managers — and skiers — are hoping for a Christmas miracle as an enormous atmospheric river takes aim at California this week.

From Los Angeles Times • Dec. 22, 2025

Water levels receded until February 2024, when an atmospheric river dumped an additional 1.5 inches of rain onto the lake, making it deep enough that people could kayak on it.

From Los Angeles Times • Dec. 12, 2025