A 3D operational hydrodynamic model, developed at the Institute of Oceanography, University of Gdansk, was used to forecast extreme hydrographic events in the Oder Estuary. The model was based on the coastal ocean circulation model known as the Princeton Ocean Model (POM); it was adapted to Baltic conditions and to a 48-h numerical meteorological forecast. Wind-driven water backup in the Oder mouth necessitated working out a simplified operational model of river discharge, based on water budget in a stream channel. The model generates 60-h forecasts of water levels, currents, water temperature and salinity in the estuary. As the model adequately approximates hydrographic variability in the estuary, it can be regarded as a reliable tool for storm surges forecasting and for the assessment of Oder water spread in the Baltic. The forecast is rapidly accessed on its designated website, thereby providing assistance in decision-making by emergency situation centres and bodies that are responsible for navigation safety, port operation and environmental and flood protection of coastal areas. It is intended to fine-tune the model so that a better fit between the observed and computed data is obtained.