Bound-waves due to sea and swell trigger the generation of freak-waves

Averaged bound-waves, arising from the interaction of a stormy-sea with a marginal swell, are used as an initial inhomogeneous disturbance which, as a result of an instability inherent in narrow homogeneous JONSWAP spectra, is amplified exponentially. This drives the system away from the equilibrium. Finally, by looking into the statistics of the underlying sea state we find that, throughout the non linear long time evolution, there is an increase in the probability of freak wave occurrence.