A novel European windstorm dataset based on ERA5 reanalysis from 1940 to present

Abstract. In this work, we present and preliminarily evaluate a novel dataset of European windstorms associated with extratropical cyclones (ETCs) based on the whole ERA5 reanalysis period (1940–present). This dataset is produced within the Copernicus Climate Change Service (C3S) Enhanced Operational Windstorm Service (EWS), to promote a knowledge-based assessment of the nature and temporal evolution of European windstorms associated with ETC. Such a dataset is primarily thought to provide high-quality, standardized data on windstorms that support various industries, particularly insurance and risk management, by offering insights into the intensity, density spatial patterns, and, if coupled downstream, with vulnerability and exposure information, the impact of windstorms. EWS includes two datasets: windstorm tracks, based on two tracking algorithms (TRACK and TempestExtremes), and windstorm footprints, produced considering both original-resolution ERA5 variables and statistically downscaled ERA5 variables, with a target grid at 1 km resolution. A preliminary analysis of the datasets shows increasing number of cold-semester windstorms and the associated footprint wind gusts magnitude over a portion of the European territory. The choice of the tracking algorithm is shown to be an important factor in the decision-making process, as it results in non-negligible uncertainties in main windstorm statistics.