Mote, Philip W., Rupp, David E., Li, Sihan, Sharp, Darrin J., Otto, Friederike, Uhe, Peter F., Xiao, Mu, Lettenmaier, Dennis P., Cullen, Heidi, Allen, Myles R.

Geophysical Research Letters

Published date October 28, 2016

Perspectives on the causes of exceptionally low 2015 snowpack in the western United States

  • States that over 80 percent of measurement sites west of 115°W experienced record low snowpack in 2015
  • Estimates a return period of 400–1000 years for California's snowpack under the questionable assumption of stationarity
  • Hydrologic modeling supports the conclusion that 2015 was the most severe on record by a wide margin
  • Shows that both human influence and sea surface temperature (SST) anomalies contributed strongly to the risk of snow drought in Oregon and Washington: the contribution of SST anomalies was about twice that of human influence
  • Finds that SSTs and humans appear to have played a smaller role in creating California's snow drought
  • Concludes that in all three states, the anthropogenic effect on temperature exacerbated the snow drought