Extreme hydro-meteorological events (e.g., storms, storm surges, floods, extreme waves, marine heatwaves) have caused serious damage to society and infrastructures at coastal areas during the past decades. The continued growth in commerce, infrastructure, and population and the impacts of climate change on coastal hazards are all contributing to an increase in the risk associated with living and working at the coast. These extreme events are caused by interactions of large- and small-scale forcing mechanisms, sequences of weather anomalies, and non-linear combined atmosphere-wave-circulation-hydrologic-morphologic responses. They can cause tremendous economic losses at coastal areas, leading to substantial damage to infrastructure and ecosystems. It is, thus, important to gain improved scientific understanding on the physical drivers controlling such extreme events, their occurrence and frequency, and the resulting impact on coastal hazards. This gain in knowledge will allow the improvement of predictive skills at daily to decadal timescales. However, state-of-the-art numerical predictions and projections are not skilful enough yet for stakeholders, water managers, and policy makers. The full capabilities of hindcasting and predicting weather-driven extremes have not been realized yet due to systematic errors in the simulation of feedbacks between atmosphere, terrestrial, and oceanic systems, particularly for coastal areas, with enhanced difficulties in representing multiscale processes and discrepancies in the modelled physics.

This special issue deals with coastal hazards and hydro-meteorological extremes, tackling coastal impacts on a broad range of environmental and economic systems. The focus will be on physical hazard drivers and hydro-meteorological extreme events, identifying the key physical processes and/or model resolutions for resolving their interactions, as well as examining their predictability at multiple timescales. Considered topics include, but are not limited to, estuarine/deltaic dynamics, hydrologic controls on sediment supply and salinity intrusion, ecosystem responses and morphologic evolution under natural and anthropogenic changes, cascading/compounding effects of extremes, and resulting coastal impacts. Papers on modelling improvements for simulating and predicting extreme events and coastal hazards and assessing their socioeconomic impact are also encouraged.