This work was presented as an abstract and oral presentation at the XIX Convegno Nazionale della Sezione GIT “Geosciences and Information Technologies,” held in Milazzo in 2025.The study examines surface circulation in the Gulf of Trieste by combining observations of an extreme river runoff event in late 2023 with targeted drifter deployments in 2024–2025. Integrating HF radar data, drifter trajectories, and model outputs, it highlights how river discharge and wind forcing interact to shape surface dynamics in this semi-enclosed basin, providing new insights into its physical variability under different environmental conditions. This study was funded by the European Union - NextGenerationEU, in the framework of the iNEST - Interconnected Nord-Est Innovation Ecosystem (iNEST ECS00000043 – CUP F43C22000190006) - Project NEREIDES-Bando Giovani Ricercatori. The views and opinions expressed are solely those of the authors and do not necessarily reflect those of the European Union, nor can the European Union be held responsible for them. The dataset was developed as part of the activities carried out by Spoke 8, Research Topic RT1 (Biology of hydrosphere ecosystems), Task S3_RT1.1.3 (Filling knowledge gaps in observation).