A coastal wave forecasting system has been developed for the improvement of marine forecasts over the Atlantic coastal waters from Cape Cod, MA to Cape Hatteras, NC. The system extends from the coast to the region near the continental shelf break. It utilizes real-time data from an existing shallow water observational network, offshore buoys and output from NOAA$(B!G(Bs WAVEWATCH III model as input to two high-resolution nowcast/forecast wave-surge models. To account for the important wave physics that occur in coastal regions, the Donelan wave model developed by the NOAA Great Lakes Environmental Research Laboratory and SWAN from the Delft University of Technology have been configured to the study area. The model has a mesh size of 1000 by 240 points with a resolution of about 1 km. Wind forcing from NOAA/NWS/NCEP$(B!G(Bs Mesoscale Eta 12km atmospheric forecast model is used to drive the wave models.

To validate both of the shallow water wave models in the region away from the coast (distances > 10km), data from five NDBC buoys observed during 2004 were used. Statistical errors of model estimates of significant wave height, mean wave period and mean wave direction are computed and demonstrate that the performance of both models is quite good. The use of WAVEWATCH III forecasts available with a 25 km spatial resolution on the offshore open boundary to account for swells generated outside of the modeled region makes a significant contribution to the accuracy of the model forecasts. The accuarcy of the predicted wave properties improves by up to 25% when the offshore wave forcing is included. During periods of low wind the improvements can exceed 50%.

This wave forecast system is part of the Urban Ocean Observatory - The New York Harbor Observing and Prediction System (NYHOPS). NYHOPS is a real-time, web-based estuarine and coastal ocean observing and modeling system for the waters of New York, New Jersey and Connecticut. The observations consist of shore-based and moored platforms at strategic locations inside the harbor and at four sites along the coast of New Jersey, each with in-situ ocean and air-sea interaction measurements. The Stevens web site imports and serves all available real-time data (www.stevens.edu/maritimeforecast).