A high-resolution operational oceanographic system is under development for Aveiro lagoon (RDFS-SPRES: http://ariel.lnec.pt/spres/). This user-friendly web-based platform integrates both short term model predictions and real time data (obtained in the scope of the monitoring network installed in frame of SPRES) in a webGIS environment. The forecasting system is based in a three-dimensional (3D) application of the hydrodynamic model SELFE3D with a spatial resolution varying from 8 km in the coastal area to 2 m in the narrow channels inside the lagoon. The ocean initial and boundary conditions for water levels, water temperature and salinity are provided by MyOcean (http://www.myocean.eu/), the meteorological forcing is predicted by the Weather Research and Forecasting (WRF) regional model developed by University of Aveiro (http://climetua.fis.ua.pt), while the Portuguese Environment Agency (SNIRH) data is used for the river boundaries forcing. With this application the end users will have easy access to local forecasts of sea levels and 3D currents, water temperature and salinity, which can be used together with the 3D VOILS oil spill model to predict and visualize oil spill plumes in case of oil spill accident.