Washington State 2021-22 Snowpack Tracking Using Maps and Charts
The amount of snow that accumulates in Washington during the annual snow season has implications throughout the year. The snowpack is considered a critical climatic variable in the Pacific Northwest that affects the water supply for agriculture, fishing, hydroelectric generation, and recreation.
Washington’s rivers, lakes, and reservoirs rely on mountain snow to provide water during the summer months. The state’s agriculture and outdoor recreation industries also depend on the snowpack for irrigation and water to support salmon and other fish habitat. The annual snow season generally lasts from October to May each year.
We are tracking this season’s snowpack using maps and graphs to better understand our water supply in 2022.
SNOW SEASON IN PROGRESS
This snow season started in November below the 1991-2020 median for most of Washington state. The Olympic and Northern Cascade chains are slightly above normal. As of last November, most of the Washington basins had well above the Median 1981-2010. Warmer temperatures in December 2020 saw a decrease across most of Washington, particularly in the Eastern Basins. The colder temperatures brought more snow from mid-February to mid-April, increasing and maintaining last season’s snowpack well above the 30-year norm (1981-2010) for most of Washington. Warmer temperatures in late April caused the snowpack to melt early in some basins east of the Cascade Mountains. The first week of May saw the Lower Yakima Basin below 60% for the 30-year standard. The Spokane and Lower Snake both dropped to 70% of the norm for the month of May.
Comparison of the snowpack of 2021 to that of last season for certain basins during the first reading of the day. The annual snow season lasts from October to May.
FIRST SNOQUALMIE FALLS AND STEVENS PASSING
Historically, Stevens Pass receives its first snow before Snoqualmie Pass. This year at Stevens Pass, 1 inch of snow arrived on November 2. Last year Stevens Pass was 2 inches on October 11. This year at Snoqualmie Pass there was 2 inches of snow on November 6th. Last year, Snoqualmie Pass was 1 inch on October 24.