The Atmospheric River

by Julie Grialou, Senior Ecologist for the Methow Conservancy

In trying to get a grasp on the “atmospheric river” event that occurred this past month, I’ve summarized various indicators and how they compare to the “average”. For the time period from December 1-20, 2025, I compared accumulated precipitation (rain plus snow as water equivalent), accumulated snowfall, and temperature for Mazama; peak riverflows for the Methow River at Winthrop; and high-elevation (Hart’s Pass) snowpack to average values for this time period.

Read the report at:

The Atmospheric River and the Stats Nature Notes Jan 2026 J Grialou