SNOWGRID – A New Operational Snow Cover Model in Austria

Abstract

We present first results of the newly developed, physically-based and spatially distributed snow cover model SNOWGRID. The model is driven with gridded meteorological input data of the in- tegrated nowcasting model INCA (8.1 - 17.7°E; 45.8 - 49.5°N) that uses remote sensing and radar data as well as ground observations and is operated by the Austrian weather service ZAMG. Addition- al data from remote sensing and ground measurements are used to validate and calibrate the model output consisting mainly of snow height and snow water equivalent maps in a spatial resolution of 100 m and a time resolution of 15 minutes in near real-time. Its energy balance mode contains partly newly developed schemes (e.g. radiation, cloudiness) based on high quality solar and terrestrial radiation data, satellite products and ground measurements. Snow physical properties and snow cover dynam- ics are currently incorporated in the model based on a simple 2-layer scheme, as the primary focus of the model are fast calculations on the large grid and to accurately represent the spatial distribution of the snow mass and depth (and not its detailed microstructural behavior), which is of great interest for authorities and the general public. Snow extent from SNOWGRID together with satellite data is also used to evaluate the effect of initializing a numerical weather prediction model such as AROME using a real snow distribution instead of climatological estimates as it is operationally done. As the model is still in development, the results and methods shown here are preliminary and not complete yet.