Progress and Challenges on Understanding Snow Droughts in the Western United States

Mountain snowpack acts as the Water Towers of the Western United States (WUS) and provides the majority of freshwater used for agriculture and public consumption. Years with below average snowpack, known as snow droughts, can cause water shortages and landscape impacts such as increased drying of soil moisture and vegetation. Progress has been made in the research community over the past decade to try and define snow droughts and understand some of the drivers and impacts, but challenges remain including an agreed upon method or definition that can be used by the operational community (e.g., forecasters and natural resource managers). Another major monitoring and communication challenge is that snow drought impacts on the timing and quantity of water supply can vary greatly across the WUS depending on the underlying causes (low precipitation, warm temperatures, or both). This presentation will describe some ways snow droughts are defined, the role of warming temperatures on snow droughts, atmospheric drivers, and ongoing efforts to communicate real-time snow drought conditions and impacts to the water resources community.

Dan McEvoy is a researcher in the Division of Atmospheric Sciences at the Desert Research Institute (DRI) where his primary focus is drought, snowpack, and mountain hydroclimate dynamics in the Western US. The Western Regional Climate Center (WRCC), one of six NOAA funded centers across the US, is housed at DRI and Dan serves as the Regional Climatologist. His work for the WRCC includes climate services, communication, and outreach, and oversight and development of user-inspired web tools to access and visualize climate data.