Spatiotemporal Variability and Large‐Scale Drivers of Storm Surge Extremes on the Northwestern European Shelf

Extreme Sea Level (ESL) poses a high risk to coastal communities and infrastructure, with its frequency and intensity projected to increase in the future. In this study, we focus on the storm surge component of sea level variability, a key contributor to extreme still water levels during storms. The spatiotemporal variability of regional extreme surge events and their connection to climate teleconnections and large-scale weather processes remains poorly understood. We analyze over 70 years of daily maximum storm surge data from a hydrodynamic model by applying state-of-the-art clustering techniques for the first time. This analysis shows that regional surge variability can be categorized into six regions in the northwestern European continental shelf, with eight sub-regions identified within the North Sea. By inspecting wind-stress curl patterns, sea-level-pressure anomalies, and storm tracks, we show that the cluster variability is consistent with regionally distinct interactions between large-scale atmospheric forcing and bathymetry. We find that the NAO and AO are positively correlated with regional surge variability in most regions, while the Scandinavian pattern (SCAN) exhibits distinct, mainly inverse links in northern clusters. Our results provide a new spatial framework for regional surge variability that could support region-specific surge prediction, surge distribution analysis, and improved assessment of how changes in storm-track behavior and large-scale climate modes translate into regional coastal flooding risk. Our study also provides a foundation for future analyses of how regional extreme surge patterns may respond to changes in oceanographic circulation (such as the Atlantic Meridional Overturning Circulation) and atmospheric forcing.