Impact of Global Warming on Snow in Ski Areas: A Case Study Using a Regional Climate Simulation over the Interior Western United States

A high-resolution (4 km) regional climate simulation conducted with the weather research and forecast (WRF) model is used to investigate potential impacts of global warming on skiing conditions in the interior western United States (IWUS). The current climate period is from November 1981 to October 2011. The future climate applies to a 30-year period centered on 2050. A pseudo global warming approach is used, with the driver re-analysis dataset perturbed by the CMIP5 ensemble mean model guidance for 2050 under the RCP 8.5. Changes in skiing season length are determined for 80 ski areas across ten US states in the Interior West considering natural snow (snow depth and snow water equivalent), artificially made snow, and other factors. The complex terrain of ski resorts is considered in the calculation of natural snow amounts. The method used to determine these snow amounts from the current climate simulation are validated against SNOTEL data where SNOTEL sites are in close proximity to the ski resorts. In order to determine the impact of elevation on climate vulnerability of ski resorts, we examine changes in snow both at base and at top elevations of the resorts.

Ski resorts in the Interior West can have significantly different elevations and vertical extend. Results show that lower elevation ski areas will have significantly less natural snow across each season in a few decades. This will lead to shorter skiing seasons. Higher elevations have only small changes in natural snow during the months January to March, especially in Wyoming and Colorado. However, seasons will also be shorter due to less natural amounts before January and after March. Ski seasons will generally start later which could prevent more ski areas from opening before the profitable Christmas holidays. Artificially made snow could help to mitigate the effects of decreased snow amounts in the early season, however, results also show that the time of suitable conditions for snow making will decrease in the future. The results show that especially at lower elevations the skiing industry will suffer greatly from global warming. Being an important contributor to the economy in the investigated areas, this has serious implications.