Regional model ICON-D2 The DWD's ICON-D2 model is a forecast model which is operated for the very-short range up to +27 hours (+45 hours for the 03 UTC run). Due to its fine mesh size, the ICON-D2 especially provides for improved forecasts of hazardous weather conditions, e.g. weather situations with high-level moisture convection (super and multi-cell thunderstorms, squall lines, mesoscale convective complexes) and weather events that are influenced by fine-scale topographic effects (ground fog, Föhn winds, intense downslope winds, flash floods). The model area of ICON-D2 covers the whole German territory, Benelux, Switzerland, Austria and parts of the other neighbouring countries at a horizontal resolution of 2.2 km. In the vertical, the model defines 65 atmosphere levels. The fairly short forecast periods make perfect sense because of the purpose of ICON-D2 (and its small model area). Based on model runs at 00, 06, 09, 12, 15, 18 and 21 UTC, ICON-D2 provides new 27-hour forecasts every 3 hours. The model run at 03 UTC even covers a forecast period of 45 hours. The ICON-D2 forecast data for each weather element are made available in standard packages at our free DWD Open Data Server, both on a rotated grid and on a regular grid. Regional ensemble forecast model ICON-D2 EPS The ensemble forecasting system ICON-D2 EPS is based on the DWD's numerical weather forecast model ICON-D2 and currently includes 20 ensemble members. All ensemble members are calculated at the same horizontal grid spacing as the operational configuration of ICON-D2 (2.2 km). Like ICON-D2, the ICON-D2 EPS ensemble system provides forecasts up to +27 hours for the same model area (up to +45 hours based on the 03 UTC run). For generating the ensemble members, some of the features of the forecasting system are changed. The method currently used to generate the ensemble members involves varying the - lateral boundary conditions - initial state - soil moisture - and model physics. For varying the lateral boundary conditions and the initial state, forecasts from various global models are used. The ICON-D2 EPS is provided on the DWD Open Data Server in the native triangular grid. Note: All previously COSMO-D2 based aviation weather products have been migrated to ICON-D2 on 10.02.2021. However, the familiar design of these products remains unchanged.

Many two-dimensional parameter fields are provided in hourly, daily, and monthly resolution in grib1 format such as pressure, precipitation, temperature, solar radiation, and wind speed components at a height of 10m and 100m. Wind speed and wind direction at different fixed heights between 40m and 200m above ground are provided in netCDF format also in hourly, daily, and monthly resolution.A detailed list of two-and three-dimensional parameters can be found here: https://opendata.dwd.de/climate_environment/REA/ParameterTables.pdf Three-dimensional parameter fields are provided in hourly, daily, and monthly resolution for temperature, specific humidity, wind speed components, and turbulent kinetic energy. For the three-dimensional fields, the lowest 6 COSMO model levels are available. The heights are invariant in time but change with topography. Over the ocean, the lowest 6 model levels correspond to a height of 10m, 35m, 69m, 116m, 178m and 258m. Constant parameters, e.g., the height of the model levels, the model surface, etc., are stored in ftp://opendata.dwd.de/climate_environment/REA/COSMO_REA6/constant/. In addition, the geographical latitudes and longitudes relate to COSMO’s rotated longitude-latitude grid.