In the C3 project "Predictability of tropical and hybrid cyclones over the North Atlantic Ocean" of the Transregional Collaborative Research Project Waves To Weather, I am working on the statistical analysis and geometric descriptions of structures and processes in the atmosphere. The goal of the project is to better understand the predictability of tropical and subtropical systems and to investigate relevant predictors. For this purpose, we want to detect processes in the atmosphere that are related to TC activity (e.g. PV streamers or African Easterly Waves) via identification and tracking algorithms, describe them using a low-dimensional parameterization, and link them to the occurrence of (sub-)tropical cyclones via statistical analysis.