Tailored seasonal snow forecasts for ski centers in Finland

In Finland, the ski industry is facing an increased vulnerability to climate change and variability, especially in southern and central regions. The late start and the early end of snowing season and the difficulties in artificial snow production due to high winter temperatures have significant impacts on winter tourism. As part of INDECIS project, Finnish Meteorological Institute developed and tested seasonal forecasts with Finnish ski centers, providing support in maintenance practices. In the beginning of the pilot, a workshop was organized representatives of the ski resorts, where the most useful indices were selected, uncertainties related to variables used in the development of indices were presented to the users and the visualization and delivery of climate outlooks were agreed. In this presentation, we will assess the quality of snow forecast and present the developed seasonal snow outlooks. 

The ECMWF long-range forecasts (SEAS5) were quality assessed and several bias-adjusted methods analysed. Finally, the raw snow forecast was bias-adjusted using the EMOS method. The forecasts were the monthly mean snow depth, and the probability of ≥1 cm of monthly mean snow depth. The forecasts were evaluated using the CRPSS. The results depend much on the season. For example, Lead month 0 and month 1 forecasts in February showed skill over most of Finland, while Lead month 0 and month 1 forecasts in November were not as skilful. 

The developed seasonal climate outlooks were tested by the users during November 2019-April 2020; following the test period a feedback survey was conducted with the users. How the perceived usefulness of forecasts transfers to the decisions made by the users is not so straight-forward. According to the feedback received only one user of the four repliers changed their plans based on the provided outlooks, and half of the respondents couldn't say if they changed their activities in any way.