Current status of SINFONY - the combination of Nowcasting and Numerical Weather Prediction on the convective scale at DWD

DWD's new Seamless INtegrated FOrecastiNg sYstem (SINFONY) will come to life in the next two years, after 5 years of research and development. For now, the system focuses on severe convective events in the very short time forecast range from minutes to 12~h. The SINFONY consists of radar Nowcasting ensembles, a high-resolution NWP-ensemble and "optimal" combinations of both with respect to various precipitation-related products as function of lead time. Various components of the SINFONY have been continuously run in near-real-time during the 2022 season.

Different interdisciplinary teams work closely together on:
a) radar Nowcasting ensembles for areal precipitation and reflectivity,
b) convective cell objects Nowcasting ensemble,
c) regional ICON-ensemble model with assimilation of high-resolution remote sensing data (3D-radar volume scans of radial winds and reflectivity, cell objects, Meteosat VIS channels)
and hourly new rapid update cycle forecasts (SINFONY-RUC-EPS) on the km-scale,
d) optimal combinations of Nowcasting and NWP ensemble forecasts in observation space (seamless forecasts of the SINFONY). Gridded precipitation and reflectivity ensemble products are targeted towards hydrologic warnings. Combined Nowcasting- and NWP cell object ensembles help evolve DWD's warning process for convective events towards a flexible
"warn-on-objects".
e) systems for common Nowcasting and NWP verification of precipitation, reflectivity and objects.
   In particular the cell object based verification provides new insights into the representation of deep convective cells in the model. 

In b) we try to forecast growth/decay ("lifecycle") of cells and give uncertainty estimates, involving Ensemble Kalman Filter and AI techniques.

For c), new innovative and efficient forward operators for radar volume scans and visible satellite data (SEVIRI-VIS) enable
direct assimilation of these data in an LETKF framework.
Advanced model physics (2-moment bulk cloud mircophysics) contribute to an improved forecast of convective clouds and reflectivity. A stochastic PBL scheme has been developed, but is not yet in daily use.

For d), the SINFONY-RUC-EPS outputs simulated reflectivity volume scan ensembles of the
entire German radar network every 5' online during its forecast runs.
Ensembles of composites and cell object tracks are generated
by the same compositing and cell detection- and tracking methods/software packages which are applied to the observations.

The "optimal" combined forecast products benefit from improvements to both Nowcasting and RUC ensembles, which goes hand in hand.

This presentation will give an overview on the system status and on the results of last years convective season. Other presentations from team members will give more details about the particular SINFONY components.