Short term forecast and monitoring of thunderstorms - status and recent developments at DWD.

During the last few years, DWD has developed a pioneering nowcasting procedure (NCS-A) for thunderstorms and strong convection based on  intelligent combination of lightning data, satellite information and Numerical Weather Prediction. The atmospheric motion vectors needed for the nowcasting are derived with the optical flow method TV-L1. Version 1 of the method NCS-A is operated 24/7 by DWD, covers the complete geostationary ring and has been very well received by aviation customers. The current developments of the nowcasting method focus on the analysis of life cycles in order to be able to improve the prediction of formation and decay of thunderstorms. This includes analysis of lightning activity. Further, work is also being done to seamlessly extend the forecast times by up to 6-8 hours through ensemble analysis of the Lightning Potential Index, provided by the DWD NWP model ICON. In addition to the mentioned developments of physical methods,  research is being also carried out on AI-based methods (neural networks) in cooperation with the University of Mainz. The presentation will start with an overview of the current 24/7 thunderstorm nowcasting. This will be followed by a presentation and discussion of the current developments at DWD aimed at providing accurate 6-8 hour forecasts of thunderstorms. Links for further readings and software will be provided as well.

_References: 

_{Müller R, Haussler S, Jerg M. The Role of NWP Filter for the Satellite Based Detection of Cumulonimbus Clouds. Remote Sensing. 2018; 10(3):386. https://doi.org/10.3390/rs10030386}

_{Urbich I, Bendix J, Müller R. Development of a Seamless Forecast for Solar Radiation Using ANAKLIM++. Remote Sensing. 2020; 12(21):3672. https://doi.org/10.3390/rs12213672.}

_{Müller R, Haussler S, Jerg M, Heizenreder D. A Novel Approach for the Detection of Developing Thunderstorm Cells. Remote Sensing. 2019; 11(4):443. https://doi.org/10.3390/rs11040443}

_{Zach, Christopher & Pock, Thomas & Bischof, Horst. (2007). A Duality Based Approach for Realtime TV-L1 Optical Flow. Pattern Recognition. 4713. 214-223. 10.1007/978-3-540-7}

_{Müller, R.; Barleben, A.; Haussler, S.; Jerg, M. A Novel Approach for the Global Detection and Nowcasting of Deep Convection and Thunderstorms. Remote Sens. 2022, 14, 3372. https://doi.org/10.3390/rs14143372}

_{Brodehl, S.; Müller, R.; Schömer, E.; Spichtinger, P.; Wand, M. End-to-End Prediction of Lightning Events from Geostationary Satellite Images. Remote Sens. 2022, 14, 3760. https://doi.org/10.3390/rs14153760}