Forecast of Nearshore Wave Parameters Using MIKE-21 Spectral Wave Model Felix Jose 1 and Gregory W. Stone 2 1 Coastal Studies Institute, Louisiana State University, Baton Rouge, LA 70803 2 Coastal Studies Institute and Department of Oceanography and Coastal Sciences, Louisiana State University, Baton Rouge, LA 70803 ABSTRACT Shallow-water wave transformation strongly depends upon coastal geomorphology and bottom sediment characteristics. Accurate prediction of wave parameters is vital for the coastal infrastructure developments and other activities. MIKE 21 SW is a new generation spectral wind wave model based on unstructured meshes. The model simu- lates the growth, decay and transformation of wind generated waves and swell in off- shore and coastal areas. The entire Gulf of Mexico was selected for the present modeling study. Along the northern Gulf Coast the grid resolution used was ~2 km while for the rest of the boundary a coarser grid of 30 km was used. Fine-scale bathymetry data (6 arc-second resolution) were used for the northern Gulf and coarse bathymetry for the rest of the basin. The data used were compiled and distributed by the National Geo- physical Data Center (NGDC) of the National Oceanic and Atmospheric Administration (NOAA). The input for the model, forecast wind data, was downloaded from the Na- tional Centers for Environmental Prediction (NCEP) of NOAA database daily (36-hr forecast). A fully spectral approach was used for the computation of the wave parame- ters. The model computed the wave parameters using the forecast wind input. Synoptic maps of significant wave height (Hs), wave period, wave direction, etc. were generated. For calibration purposes, output was also generated for the NDBC buoy locations and Wave-Current-Surge Information System (WAVCIS) stations located off the Louisiana coast. During fair weather conditions the predicted wave parameters show a strong cor- relation with measured wave parameters. During extreme weather conditions (hurricanes and tropical storms) predicted values typically were lower than observa- tions. This discrepancy can be attributed to the scale and accuracy of the input wind data. INTRODUCTION Wave-prediction and hindcast studies are important in ocean engineering, coastal infrastructure development and management. Knowledge of parameters describing the wave field, currents and water level is essential to almost all marine related activities (Kumar and Stone, in press). Wind-generated ocean surface waves are identi- fied as the major driving force for nearshore circulation and sediment transport in the surf zone and inner conti- nental shelf (Wright et al., 1991). As the waves approach shallow water, wave energy spectra evolve due to re- Jose, F., and G. W. Stone, 2006, Forecast of nearshore wave parameters using MIKE-21 Spectral wave model: Gulf Coast Association of Geological Societies Transactions, v. 56, p. 323-327. 323