Maritime forecasting at KNMI is supported by numerical maritime models which are driven by the atmospheric limited area model HIRLAM. Research and development is aimed at improvement of existing models, by applying recent knowledge and improved infrastructure.

• Wave prediction model NEDWAM (implementation of WAM in the Netherlands with emphasis on bottom depth); waves are predicted with this model up to 48 hours ahead. Performance of NEDWAM is improved by assimilation of real-time measured spectra.
• Storm surge model WAQUA-in-Simona/DCSM98; water level variations due to wind and pressure at the North Sea are predicted up to 48 hours ahead.
• Practical usefulness of the models is increased by applying statistical methods (post-processing, guidance and ensemble forecasting).
• Computation of the mean surface wind at spatially small scales by a downscaling technique.