Since 2017, the SINFONY (Seamless INtegrated FOrecastiNg sYstem) project has been under development at the Deutscher Wetterdienst (DWD). It is aimed to provide a seamless ensemble system for early predictions and warnings of severe weather events by combining the nowcasting based on extrapolating observed radar reflectivity and short-term forecasts initiated from the Rapid Update Cycle (RUC) of data assimilation for the convection-permitting ICON (ICOsahedral Nonhydtostatic) model. So far, the ICON-RUC setup has been extensively tested for convective summer cases. In this study, a series of sensitivity experiments have been conducted for the winter precipitation, including the choice of microphysics schemes and the Latent Heat Nudging (LHN). Results show that within data assimilation cycles the two-moment scheme outperforms the one-moment scheme, and the LHN has also positive impacts. For the 6-h reflectivity forecasts, the two-moment scheme is clearly better than the one-moment scheme and the added values by using the LHN persist almost 6 h. For the precipitation forecasts, the two-moment scheme also exhibits advantage for the light precipitation, however, for the moderate precipitation, the one-moment scheme prevails. Current results indicate that the two-moment has to be enhanced for the moderate precipitation in winter.

中文翻译：

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使用 ICON-KENDA 系统研究冬季病例的雷达数据同化


自 2017 年以来，Deutscher Wetterdienst （DWD） 一直在开发 SINFONY（无缝集成 FOrecastiNg sYstem）项目。它旨在通过结合基于外推观测到的雷达反射率的临近预报和从允许对流的 ICON （ICOsahedral Nonhydtostatic） 模型的数据同化的快速更新周期 （RUC） 发起的短期预报，为恶劣天气事件的早期预测和警告提供一个无缝的集成系统。到目前为止，ICON-RUC 装置已经针对夏季对流情况进行了广泛的测试。在本研究中，对冬季降水进行了一系列敏感性实验，包括微物理方案的选择和潜热推动 （LHN）。结果表明，在数据同化周期内，两矩方案优于一矩方案，LHN 也具有积极影响。对于 6 h 反射率预报，两矩方案明显优于一矩方案，使用 LHN 的附加值持续了近 6 h。对于降水预报，两矩方案也显示出对轻降水的优势，但是，对于中度降水，一矩方案占上风。目前的结果表明，对于冬季的中等降水，必须增强 two-moment 。