Quo vadis SINFONY - the seamless combination of Nowcasting and ICON Rapid Update Cylce NWP at DWD

The presentation will provide an overview on the status and future plans for DWD's new Seamless Integrated Forecasting system (SINFONY) for very-short-range high resolution forecasts, which consists of several components:

1) The radar Nowcasting ensembles STEPS-DWD and convective cell objects ensemble KONRAD3D-EPS including hail and life cycle information.
2) The ICON-RUC-EPS with hourly LETKF assimilation of 3D radar volumes, Meteosat VIS and IR channels, hourly new forecasts using the Seifert-Beheng 2-moment microphysics scheme with prognostic hail and advanced forward operators for radar (EMVORADO) and VIS/IR satellites RTTOV-MFASIS).
3) Optimal combinations ("blending") of the Nowcasting and NWP ensemble forecasts in observation space, which constitute the seamless forecasts. The areal INTENSE precipitation- and reflectivity ensemble is targeted towards hydrologic warnings. It also serves as input to quickly estimate a pluvial flash-flood potential for very small river catchments on short leadtimes (AREA). The combined Nowcasting- and NWP cell object ensemble KONRAD3D-SINFONY helps evolve DWD’s warning process for convective hazards.
4) Common Nowcasting and NWP verification systems for precipitation, reflectivity and cell objects help to continuously improve the SINFONY components.

After several years of intensive development in a project framework, "fitness for operations" of the components ICON-RUC, STEPS-DWD and INTENSE has been achieved, especially for small-scale strong convective events from observation time up to 12h. Weather radar is at the heart of it, having DWD's warning process (forecasters, automated systems) and the hydrological authorities in mind. The ICON-RUC-EPS already served 1 1/2 years in operations and received very positive feedback from it's users. INTENSE is close to operationalisation and KONRAD3D-SINFONY is strongly evolving. Their long-term maintenance and further development is a cross-cutting activity of several disciplines and sections within DWD.

In parallel, the systems will be further improved in a new project phase SINFONY-3.0 (2025-2029) towards seamless forecasts for other parameters/phenomena and other user groups:
- Temperature, wind, cloudiness, fog, solar radiation, visibility, ceiling for
- aeronautical forecasts, renewables, customer data portals,
- with good year-round performance,
- and seamless forecasts beyond 12h.
For this, we try to improve the ICON-RUC forecasts for these parameters, and, by using AI-methods, we blend ICON-RUC-EPS into ICON-D2-EPS and we integrate MTG satellite data into our Nowcasting and combined products.