Snow days? Snowmaking adaptation and the future of low latitude, high elevation skiing in Arizona, USA

Inter-annual snow reliability is a key short-term concern for Arizona's high elevation, low latitude ski resorts. Variability is linked to the El Niño Southern Oscillation (ENSO)-warm phase conditions typically portend a good ski season and vice versa. To operate more consistently in the medium-term Arizona's two largest ski resorts plan to expand snowmaking. Snowmaking is a water and temperature constrained adaptation. One of the two resorts has overcome its water constraint by contracting with a municipality for treated wastewater. To assess the temperature constraint downscaled global coupled climate model temperature projections were compared to technical thresholds for the manufacture of snow at three time steps. In 2030, a period coincident with the lifetime of the investments, snowmaking will likely remain feasible. However, by 2050, temperatures will likely exceed technical thresholds in the shoulder seasons meaning that in years when natural snowfalls are poor the ski season may be curtailed. By 2080, without snowmaking efficiency improvements, warmer temperatures will make snowmaking increasingly more expensive and resort managers may need to plan for a future where operations and snowmaking are shifted to higher elevation, shaded, more snow reliable runs.