Boukhanovsky A.V., Lopatoukhin L.I.
Wind waves are considered. Differences between extreme and freak waves are discussed. It is specified, that not any big wave (surge) is unusual. Such wave should have a set of certain properties and therefore can be considered as a multidimensional random variable. Generalization of the field measurements data has allowed to estimate a freak wave appearance probability. Abrupt change of wave spectral structure is one of the approaches to forecast the freak wave appearance.
