Predicting rogue waves in random oceanic sea states

Using the inverse spectral theory of the nonlinear Schrodinger (NLS) equation we correlate the development of rogue waves in oceanic sea states characterized by the JONSWAP spectrum with the proximity to homoclinic solutions of the NLS equation. We find in numerical simulations of the NLS equation that rogue waves develop for JONSWAP initial data that is near'' NLS homoclinic data, while rogue waves do not occur for JONSWAP data that is far’’ from NLS homoclinic data. We show the nonlinear spectral decomposition provides a simple criterium for predicting the occurrence and strength of rogue waves (PACS: 92.10.Hm, 47.20.Ky, 47.35+i).