Assessing the Sensitivity of Wasatch Mountain Snowfall to Temperature Variations

TitleAssessing the Sensitivity of Wasatch Mountain Snowfall to Temperature Variations
Publication TypeConference Proceedings
Year of Conference2009
AuthorsJones, L. P., and Horel J. D.
Conference Name77th Annual Western Snow Conference
Series TitleProceedings of the 77th Annual Western Snow Conference
Date PublishedApril 2009
PublisherWestern Snow Conference
Conference LocationCanmore, AB
KeywordsWasatch Mountains, climate change, snow sensitivity, SNOTEL

Three methods are employed in this study to estimate the sensitivity of snow falling in the Wasatch Mountains of northern Utah to observed and projected changes in atmospheric temperature. Daily precipitation data from 1 October to 30 April 1979-2008 are examined from selected snowpack telemetry (SNOTEL) sites in northern Utah. Profiles of wet bulb temperature from near crest level (700 mb) to elevations along the mountain slopes of selected watersheds are estimated on days with precipitation soundings launched from the nearby Salt Lake City airport. The rain-snow line is assumed to correspond uniformly to the elevation of the wet bulb temperature equal to 1oC. Probability distribution functions of the fraction of precipitation falling as snow as a function of daily wet-bulb temperature are computed. The percentage of precipitation estimated to fall at wet-bulb temperatures in the range 0-1oC is assumed to switch from snow to rain if temperatures increase by 1oC. While the sensitivity to temperature depends strongly on elevation within the watershed, an increase in tropospheric temperatures of 1oC is estimated to lead to an 8-10% decrease in snow when averaged over the selected watersheds.