Waves of heavy rainfall in early December 2025 spurred landslides and flooding in parts of the Pacific Northwest.
Waves of heavy rainfall in early December 2025 spurred landslides and flooding in parts of the Pacific Northwest. The deluge was the result of a potent atmospheric river that took aim at the region starting around December 7.
Atmospheric rivers are long, narrow bands of moisture that move like rivers in the sky, transporting water vapor from the tropics toward the poles. They occur around the planet, most often in autumn and winter, with the U.S. West Coast typically affected by moist air that originates near Hawaii. In this event, however, some of the moisture arrived from even farther away, originating roughly 7,000 miles (11,000 kilometers) across the Pacific from near the Philippines.
This map shows the total precipitable water vapor in the atmosphere at 11:30 p.m. Pacific Time on December 10. It is derived from NASA’s GEOS (Goddard Earth Observing System) and uses satellite data and models of physical processes to approximate what is happening in the atmosphere.
Read more at: NASA
Photo Credit: NASA Earth Observatory images by Lauren Dauphin, using GEOS data from the Global Modeling and Assimilation Office at NASA GSFC.
