Hourly probabilistic snow forecasts over complex terrain: a hybrid ensemble postprocessing approach
- 1Department of Statistics, Faculty of Economics and Statistics, Universität Innsbruck, Universitätsstraße 15, 6020 Innsbruck, Austria
- 2Institute of Atmospheric and Cryospheric Sciences, Faculty of Geo- and Atmospheric Sciences, Universität Innsbruck, Innrain 52, 6020 Innsbruck, Austria
- 3Department of Electrical Engineering, Technical University of Denmark, Elektrovej, Building 325, 2800 Kgs. Lyngby, Denmark
Abstract. Accurate and high-resolution snowfall and fresh snow forecasts are important for a range of economic sectors as well as for the safety of people and infrastructure, especially in mountainous regions. In this article a new hybrid statistical postprocessing method is proposed, which combines standardized anomaly model output statistics (SAMOS) with ensemble copula coupling (ECC) and a novel re-weighting scheme to produce spatially and temporally high-resolution probabilistic snow forecasts. Ensemble forecasts and hindcasts of the European Centre for Medium-Range Weather Forecasts (ECMWF) serve as input for the statistical postprocessing method, while measurements from two different networks provide the required observations.
This new approach is applied to a region with very complex topography in the eastern European Alps. The results demonstrate that the new hybrid method allows one not only to provide reliable high-resolution forecasts, but also to combine different data sources with different temporal resolutions to create hourly probabilistic and physically consistent predictions.