ERA5-Based Environmental Characteristics of F2 Tornadoes in Germany since 1950

Based on a climatology (Marcus Bayer, 2021), an average of four F2 tornadoes occur in Germany every year. These tornadoes are often strong enough to cause damage, which is why it can be assumed that they are well documented. However, looking back over the decades, not all events are equally detailed.

In this study, we analyzed a carefully selected sample of 150 well-documented F2 tornadoes that occurred in Germany between 1950 and today. Each of these cases includes precise location and timing information, allowing for deeper investigation via reanalysis data. We have analyzed the seasonal distribution through to the daily cycle, all illustrated by clear graphics. Further we investigated how the large-scale weather pattern (synoptic flow regime) develops prior to tornado development by analyzing wind profiles from proximity soundings. Our analysis is seasonally structured, focusing on the environmental parameters that favor tornado genesis during spring, summer, and autumn. This includes both kinematic and thermodynamic values, which we derived from hodographs and Skew-T log-P diagrams. Additionally, we explored what kind of thunderstorms these tornadoes were associated with—whether they formed in isolated supercells, along squall lines, or within other storm types. Therefore, we used radar data provided by the German Weather Service (DWD).

The key findings of this study not only contribute to a better understanding of the environmental conditions that lead to damaging tornadoes in Germany, but also support efforts to improve severe weather forecasting. The data sample also leaves room for further investigation. We welcome feedback and insights from operational storm forecasters, meteorologists, and tornado experts to enhance the understanding of these events.