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Projected changes in snowfall extremes and interannual variability of snowfall in the western U.S.

Author(s): A.C. Lute, John T. Abatzoglou, Katherine C. Hegewisch
Year Published: 2015

Projected warming will have significant impacts on snowfall accumulation and melt, with impli- cations for water availability and management in snow-dominated regions. Changes in snowfall extremes are confounded by projected increases in precipitation extremes. Downscaled climate projections from 20 global climate models were bias-corrected to montane Snowpack Telemetry stations across the western United States to assess mid-21st century changes in the mean and variability of annual snowfall water equivalent (SFE) and extreme snowfall events, defined by the 90th percentile of cumulative 3 day SFE amounts. Declines in annual SFE and number of snowfall days were projected for all stations. Changes in the magnitude of snowfall event quantiles were sensitive to historical winter temperature. At climatologi- cally cooler locations, such as in the Rocky Mountains, changes in the magnitude of snowfall events mir- rored changes in the distribution of precipitation events, with increases in extremes and less change in more moderate events. By contrast, declines in snowfall event magnitudes were found for all quantiles in warmer locations. Common to both warmer and colder sites was a relative increase in the magnitude of snowfall extremes compared to annual SFE and a larger fraction of annual SFE from snowfall extremes. The coefficient of variation of annual SFE increased up to 80% in warmer montane regions due to projected declines in snowfall days and the increased contribution of snowfall extremes to annual SFE. In addition to declines in mean annual SFE, more frequent low-snowfall years and less frequent high-snowfall years were projected for every station.

Citation: Lute AC, Abatzoglou JT, Hegewisch KC. 2015. Projected changes in snowfall extremes and interannual variability of snowfall in the western U.S. Water Resources Research 51, 960–972. Doi:10.1 002/2014WR016267.
Topic(s): Fire Behavior, Weather
Ecosystem(s): None
Document Type: Book or Chapter or Journal Article
NRFSN number: 15647
Record updated: Jun 14, 2018