Jul 1, 2014

Extent of the rain‐snow transition zone in the western U.S. under historic and projected climate

Klos, P. Zion, Link, Timothy E., Abatzoglou, John T.
Geophysical Research Letters
  • Investigates the extent of the rain-snow transition zone across the complex terrain of the western United States for both late 20th century climate and projected changes in climate by the mid-21st century
  • Uses observed and projected temperature and precipitation data at 4 km resolution with an empirical probabilistic precipitation phase model to estimate and map the likelihood of snow versus rain occurrence
  • This approach identifies areas most likely to undergo precipitation phase change over the next half century
  • At broad scales, these projections indicate an average 30% decrease in areal extent of winter wet-day temperatures conducive to snowfall over the western United States
  • At higher resolution scales, this approach identifies existing and potential experimental sites best suited for research investigating the mechanisms linking precipitation phase change to a broad array of processes, such as shifts in rain-on-snow flood risk, timing of water resource availability, and ecosystem dynamics
  • Finds that the western U.S. is projected to see an average monthly reduction from ~53% to ~24% in the extent of the land area within a wintertime snowfall regime