Meteoceanographic Patterns Associated with Severe Coastal Storms Along the Southern Coast of Brazil

Extratropical cyclones are the main drivers of high-energy wave events along the southern coast of Brazil, frequently generating coastal storms and hazardous conditions. This study analyzes the occurrence and characteristics of extreme wave events between 2001 and 2020 along the coastal zone from Arroio Chuí to Cabo de Santa Marta, based on warnings of sea state hazards issued by the Brazilian Navy Hydrographic Center. Events were selected using the 95th percentile of significant wave height, considering only episodes with waves exceeding 4.0 m reaching the coast. To avoid double-counting, consecutive warnings within two days were grouped as a single event. Reanalysis data from ERA5 were used to describe the associated atmospheric and oceanographic patterns. A total of 51 high-impact coastal storm events were identified, with seasonal distribution showing higher frequency during winter (19 cases) and autumn (15 cases). Out of these events, 25 were associated with adverse navigation conditions at the coastal bar, accounting for 355 hours of impracticability. Results highlight the dominant role of strong winds and frontal systems in generating extreme sea states and their socio-economic impacts. The study provides a climatological baseline for the region and contributes to improving forecasts and risk management strategies under changing climate conditions.