HSAMI is a 23-parameter, lumped, conceptual, rainfall–runoff model developed by Hydro-Québec, and which has been used to forecast natural inflows for over 20 years (Fortin 2000). HSAMI is used by Hydro-Québec for daily forecasting of natural inflows on nearly 100 watersheds with drainage areas ranging from 160 to 69,195 km². HSAMI was also used in several flow forecasting and climate change impact studies (e.g., Minville et al. 2008, 2009; Chen et al. 2011a, 2011b, 2012; Poulin et al. 2011; Arsenault et al. 2013). Of HSAMI's 23 parameters, two account for evapotranspiration, six for snow accumulation/melting, ten for vertical water movement, and five for horizontal water movement (see Table 1). Vertical flows are simulated with four interconnected linear reservoirs (snow on the ground, surface water, unsaturated and saturated zones). Horizontal flows are routed through two unit hydrographs and one linear reservoir. In addition, the model takes into account snow accumulation, snowmelt, soil freezing/thawing, and evapotranspiration. Model calibration was done automatically using the covariance matrix adaptation evolution strategy (CMAES) (Hansen & Ostermeier 1996, 2001), following the conclusions of Arsenault et al. (2014).