There are rivers in the sky

Illustration of atmospheric rivers

Image: NOAA

There are rivers in the sky called atmospheric rivers, sometimes nicknamed the Pineapple Express

What causes an atmospheric river? Why is this band of moisture confined to a narrow strip, sometimes only a few hundred miles across? How does California’s topography influence an atmospheric river and contribute to rainfall and snowfall in the state?


Image: GOES-West, NASA

Look for the narrow band of clouds originating near Hawaii (center left). Those clouds, filled with tropical moisture, travel to the coast of California as an atmospheric river. This weather phenomenon is called the Pineapple Express and is a contributor to the California water cycle. Occasionally, an atmospheric river reaches San Diego.


NOAA: What are atmospheric rivers?

NOAA: Atmospheric river portal

YouTube: GOES-West Satellite Sees Pineapple Express

Earth and Space Science

More Activities & Resources:

The Moreton Bay Fig Tree, behind the San Diego Natural History Museum in Balboa Park
San Diego County is home to a unique geologic feature

Image: San Diego Zoo Global


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