At Instituto de Meteorologia (IM), the sea state forecasts are based on three numerical models. Two such models are developed in the ECMWF (www.ecmwf.int), namely the WAve Model (WAM), global model with a spatial resolution of 0.25º, and the limited area model European Shelf Model (LAM), covering most of the North Atlantic with 0.1º resolution. Both models have a spectral discretization of 36 frequencies and 36 directions. IM recently implemented the Simulating WAves Nearshore (SWAN) model in the adjacent region to Portugal mainland, with a 0.05º horizontal resolution and a spectral discretization of 36 frequencies and 36 directions.

 

SWAN is a third-generation wave, developed at Delft University of Technology (TUDelft), Holanda (www.swan.tudelft.nl). At IM, SWAN runs over a domain 44ºN/14ºW/36ºN/6ºW, with a horizontal resolution of 0.05ºand a spectral discretization of 36 frequencies and 36 directions. SWAN is forced by the 10 m wind field from the atmospheric limited area model ALADIN (www.cnrm.meteo.fr/aladin/), which runs at IM with 9 km horizontal resolution, and by the spectral density from the European Shelf Model (www.ecmwf.int), which has a horizontal resolution of 0.1º and a spectral discretization of 36 frequencies and 36 directions. The SWAN model predictions are available up to 3 days with a hourly frequency.