Soil-vegetation-atmosphere interactions have been historically underrepresented and overlooked in water budgets and hydrological models of mountain basins. Collective knowledge focussed on these interactions during spring snowmelt and green-up transition seasons is particularly sparse in the Canadian Rockies. Mountain areas are sensitive to climate warming, variability and extremes, which directly impact subalpine forests. Previous studies by Langs et al (2020, 2021) identified the winter-spring transition period and subsequent snowmelt as the most important period for subalpine forest summertime evapotranspiration. To explore how interannual variability in weather and precipitation patterns affects transition season evapotranspiration, precipitation, peak snow accumulation, snowmelt and snowcover depletion, soil moisture and evapotranspiration were observed from multiple stations over an 8-year period (2016-2023) in the subalpine forest zone of Fortress Mountain Research Basin, Alberta. The subalpine forest started transpiring while snow was still melting on the ground. There was a close relationship between subsequent evapotranspiration and both the length of the snowmelt period and peak snow accumulation. Subalpine forests were able to initiate transpiration early in the snowmelt period and take advantage of liquid soil moisture content increases from infiltrating snowmelt water, and so transpired larger volumes of water in years with deeper and more slowly melting snowpacks. Comparing and contrasting the observed evapotranspiration and water use over the 8-year study period shows the impact of mountain snow drought on forest water use and water balance and informs the development of improved hydrological models of high mountain basins and estimations of how these environments might respond to climate change.