Recently, coastal disasters due to long period swell induced by storms increase in the Japanese harbors. For example, a fishery boat was capsized in the Kurihama bay by the high waves which suddenly appeared in a calm weather. At that time, T0402 (typhoon No.2 in 2004) passed through in the offshore, and typical swell profiles were observed not only in the Ashikajima station inside the Kurihama bay but also in several NOWPHAS stations along the Pacific Ocean from the Kanto region to the Shikoku region. The swell profile appeared with a uniform delay time in such observation stations according with their locations. Therefore, it seems to be possible to estimate the swell arrival time by using the observed data in the different stations.
　In this study, the analytical approaches were conducted by using the observed wave data. The cross correlation coefficients were calculated in order to estimate the delay of swell arrival time, and their characteristics were studied in the typhoon course and in the relationship between the location of target port and the position of typhoon. The swell arrival probability in a region can be judged with the classified pattern of typhoon course, averaged velocity and so on. The following remarks were derived, for example a swell approaches to the coasts of the Japan Sea after the typhoon passing. Meanwhile, the swell arrives at the Pacific coasts of Japan before the typhoon approaching.