Tales of Storms: Climate Storylines of Extreme Precipitation Events in Autumn 2024

The autumn of 2024 witnessed a series of extreme precipitation events that caused widespread impacts, highlighting the importance of investigating the role of climate change in impacting these phenomena. This study employs novel kilometre-scale (km-scale) storyline simulations using the IFS-FESOM coupled climate model to examine three major events—Hurricane Helene in the United States, severe flooding in Valencia, Spain, and Storm Boris that brought extreme precipitation to Central and Eastern Europe—under preindustrial, present-day, and future climate forcings. By nudging the evolution of large-scale atmospheric dynamics to ERA5, the storyline approach isolates thermodynamic changes due to anthropogenic warming while maintaining consistency with the observed event structures. The km-scale resolution enables a detailed representation of topographical influences, local-scale processes such as moisture convergence, and convective dynamics, providing critical insights into how the intensity, spatial distribution, and other characteristics of heavy precipitation may unfold in different climates. This study lays the foundation for a comprehensive set of storylines of high-impact extreme precipitation events, offering actionable information for decision-makers and increasing public understanding of the impact of climate change on extreme weather risks.