Short-term forecasting model ICON-D2

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.区域数值模式ICON-D2 德国气象局（DWD）的ICON-D2模式是一款极短期数值预报模式，预报时效最高可达+27小时（03 UTC起报的预报时效可达+45小时）。得益于精细的网格分辨率，ICON-D2可显著提升极端天气事件的预报精度，例如高空湿对流天气（超级单体、多单体雷暴、飑线、中尺度对流复合体）以及受精细地形效应影响的天气事件（地面雾、焚风、强下坡风、山洪）。 ICON-D2的模式区域覆盖德国全境、比荷卢三国、瑞士、奥地利及部分周边邻国，水平分辨率为2.2千米。垂直方向上，该模式共设置65个大气分层。 鉴于ICON-D2的应用定位与较小的模式区域，其较短的预报时效具备合理性。该模式每日在00、06、09、12、15、18、21 UTC进行起报，每3小时更新一次27小时时效的预报；而03 UTC起报的模式运行则可提供长达45小时的预报时效。 各气象要素的ICON-D2预报数据将以标准数据包形式，在免费的DWD开放数据服务器上发布，数据支持旋转网格与规则网格两种格式。 集合预报区域模式ICON-D2 EPS ICON-D2 EPS集合预报系统基于德国气象局（DWD）的数值天气预报模式ICON-D2构建，当前包含20个集合成员。所有集合成员均采用与业务化ICON-D2模式一致的水平网格间距（2.2千米）。与ICON-D2相同，ICON-D2 EPS的预报区域与预报时效保持一致：其余起报时刻的预报时效最高可达+27小时，03 UTC起报的预报时效可达+45小时。 集合成员的生成通过扰动预报系统的部分参数实现，当前采用的扰动方法包括对侧边界条件、初始场、土壤湿度以及模式物理过程进行扰动。其中，侧边界条件与初始场的扰动依托多套全球模式的预报结果完成。 ICON-D2 EPS的预报数据以原生三角网格形式在DWD开放数据服务器发布。 注：所有此前基于COSMO-D2的航空气象产品已于2021年2月10日迁移至ICON-D2平台，但其产品的原有设计保持不变。