Prediction of Occurrences of Steep and High Waves in Deep Water

Abstract

Estimates for encounter probabilities of occurrence of steep and high waves in deep water for given sea states by using two different parametric models for the joint distribution of crest front steepness and wave height are presented. The parametric models are fitted to the same data set, with data from a zero‐downcross analysis of wave data obtained from measurements at sea on the Norwegian continental shelf. The probability of occurrence of waves with different crest front steepness are estimated with each parametric model for a family of JONSWAP spectra. An example is given where the probabilities of occurrence of “extreme waves,” which are considered to be critical to capsizing of smaller vessels, are estimated with one parametric model for sea states described by significant wave height and mean zero‐crossing period.