Extreme Wave Events in Directional, Random Oceanic Sea States

We discuss the effects of the directional spreading on the occurrence of extreme wave events. We numerically integrate the envelope equation recently proposed by Trulsen et al., Phys of Fluids 2000, as a weakly nonlinear model for realistic oceanic gravity waves.Initial conditions for numerical simulations are characterized by the spatial JONSWAP power spectrum for several values of the significant wave height, steepness and directional spreading. We show that by increasing the directionality of the initial spectrum the appearance of extreme events is notably reduced.