Validation of a wave forecast system for Galway Bay

Abstract

An operational wave forecast system for the area of Galway Bay is presented. Three numerical models are implemented: Weather Research and Forecasting (WRF), Wavewatch III (WWIII) and Simulating Waves Nearshore (SWAN). GFS (Global Forecast System) winds, from NCEP (National Centres for Environmental Prediction), are used to force the WWIII model, while WRF winds are used to force the SWAN model. Bathymetries for WWIII and SWAN were obtained from NOAA’s GEODAS (Geophysical Data System) data base and from GEBCO (General Bathymetric Chart of the Oceans), hosted by BODC. The wave generation model, WWIII, is used to simulate waves for the whole North Atlantic, whereas the SWAN model runs for the Irish west coast, with a nested grid for Galway Bay. Forecast products of 7 days are produced daily, with a warm up of 4 days. The validations of the forecast system were made for both wind and wave parameters with data from buoys located in the Irish coast and inside Galway Bay. Comparisons in the time domain as well as a statistical analysis were performed. Overall, the wave forecast system gave good results closely reproducing the real data, with a low error.