A3-dimensional baroclinic model of the North Sea and the Baltic Sea, designed for a daily operational use is described in detail. The model is based on a similar model running in operational mode at the German Federal Maritime and Hydrographic Agency (BSH) in Hamburg, Germany. The operational forecasts started in 1995 with a daily 24-hour forecast and was later extended to 48 hours. The model is mainly forced by SMHI's operational atmospheric model (HIRLAM), but also by river runoff from an operational hydrological model and wave radition stress from a wind wave model. The present version of the model is set up on a nested grid where a 12 nautical mile (nm) grid covers the whole area while Skagerrak, Kattegat, the Belt Sea and the Baltic Sea are covered with a 1 nm grid. A parallelized version of the model has been developed and runs on a distributed memory parallel computer.