A Review of the Hydrologic Response Mechanisms During Mountain Rain-on-Snow

Mountain rain-on-snow (ROS) generates large flooding events worldwide. Climate warming will enhance the frequency, magnitude, and widespread nature of these events. Past studies indicate rainfall, not snowmelt, typically drives much runoff response during ROS. However, there is substantial event-to-event variability—resulting from shifting atmospheric drivers nuanced physical mechanisms governing water flow through a snowpack. Historically, turbulent fluxes were assumed to dominate energy balance for snowmelt Recent research nonetheless suggests that other components might be larger depending on: 1) time year; 2) elevation; 3) aspect slope. This mini review summarizes literature on processes ROS proposes moving forward we utilize terms “active” “passive” describe snowpack’s contribution ( via snowmelt) terrestrial input (TWI) Active snowpacks readily contribute meltwater TWI balance, bolstering rainfall-runoff totals. Passive do melt, but simply convey rainwater snow matrix. In both snowpack cases, preferential paths transmissivity. proposed classification scheme help researchers managers better communicate interpret past findings, aid in forecasting discussions future