Decreases in Mean Annual Streamflow and Interannual Streamflow Variability Across Snow‐Affected Catchments Under a Warming Climate

Abstract It has been found that a decreased fraction of precipitation falling as snow in a warmer climate significantly affects streamflow. Here, based on observations from 631 catchments over the contiguous United States, we proposed a framework to investigate the first‐order and second‐order hydro‐climatic relationships between annual streamflow and snowfall fraction. Results show that in addition to the mean annual streamflow, the interannual streamflow variability will also decrease with lower snowfall fraction in the context of warming. The positive relationship between streamflow variability and snowfall fraction may result from the asymmetric hydrological effects of snowfall in the wet and dry years. To our knowledge, it is the first attempt to detect the role of snowfall on the streamflow variability. This study provides new understandings of the second‐order hydro‐climatic effects, and these findings will facilitate decisions for water resource management in a changing climate.