Current status of SINFONY - the combination of Nowcasting and Numerical Weather Prediction on the convective scale at DWD
Authors: Blahak Ulrich ,   Team SINFONY
Published: June 2022

&lt;p&gt;DWD's new Seamless INtegrated FOrecastiNg sYstem (SINFONY) is about to come to life in the next two years,&lt;br&gt;after 5 years of research and development.&lt;br&gt;For now, the system focuses on severe convective events in the very short time forecast range from minutes to 12~h.&lt;/p&gt;&lt;p&gt;There are different &quot;optimal&quot; forecast methods for different forecast lead times and different weather phenomena.&lt;br&gt;Focusing on precipitation and convective events up to some hours ahead, radar extrapolation techniques (Nowcasting)&lt;br&gt;show good skill up to about 2 h ahead (depending on the situation), while numerical weather prediction (NWP)&lt;br&gt;outperforms Nowcasting only at later hours. Ensembles of both Nowcasting and NWP help&lt;br&gt;to assess forecast uncertainties.&lt;br&gt;&quot;Optimally&quot; combining precipitation forecasts from Nowcasting and NWP&lt;br&gt;as function of lead time leads to the seamless forecasts of the SINFONY.&lt;/p&gt;&lt;p&gt;Different interdisciplinary teams work closely together in developing&lt;br&gt;a) radar Nowcasting ensembles for precipitation, reflectivity and convective cell objects,&lt;br&gt;b) a regional ICON-ensemble model with extensive data assimilation of high-resolution remote sensing data (3D radar volume scans of radial winds and reflectivity, cell objects, Meteosat VIS channels and lightning)&lt;br&gt;and hourly new rapid update cycle forecasts (SINFONY-RUC-EPS) on the km-scale,&lt;br&gt;c) optimal combinations of Nowcasting and NWP ensemble forecasts in observation space. Gridded combined precipitation and reflectivity ensembles are targeted towards hydrologic warnings. Combined Nowcasting- and NWP cell object ensembles help evolve DWD's warning process for convective events towards a flexible&lt;br&gt;&quot;warn-on-objects&quot;.&lt;br&gt;d) systems for common Nowcasting and NWP verification of precipitation, reflectivity and objects.&lt;br&gt;&amp;#160; &amp;#160;In particular the cell object based verification will provide new insights into the representation of deep convective cells in the model.&amp;#160;&lt;/p&gt;&lt;p&gt;For b), new innovative and efficient forward operators for radar volume scans and visible satellite data enable&lt;br&gt;direct operational assimilation of these data in an LETKF framework.&lt;br&gt;Advanced model physics (stochastic PBL scheme, 2-moment bulk cloud mircophysics) contribute to an improved forecast of convective clouds.&lt;/p&gt;&lt;p&gt;For c), the SINFONY-RUC-EPS outputs simulated reflectivity volume scan ensembles of the&lt;br&gt;entire German radar network every 5' online during its forecast runs.&lt;br&gt;Ensembles of composites and cell object tracks are generated&lt;br&gt;by the same compositing and cell detection- and tracking methods/software packages which are applied to the observations.&lt;/p&gt;&lt;p&gt;During the last year, all these methods have been further consolidated, and the RUC, along with some of the new nowcasting methods, has been run daily in a continuous test forecast mode.&lt;/p&gt;&lt;p&gt;This presentation will give a short overview on the activities of the last year and selected results of the test forecast mode.&lt;br&gt;Other presentations from SINFONY team members will give more details about the particular SINFONY components.&lt;/p&gt;