Between the evening of October 23^rd and the evening of October 24^th 2017, a sea storm hit the city of Bari, along the Adriatic coast, in the south of Italy, causing widespread damages. Due to the absence of direct observations of wave characteristics, the present paper is aimed to (i) compare the development of the occurred sea storm as hindcasted by '84 method with the predictions by atmosphere-ocean numerical models and satellite observations and (ii) estimate the most reliable value of the significant wave height, H_s, at the peak of the sea storm, with its associated return period. As a result, the '84 showed the better agreement with the satellite observations in determining the value of H_s at the peak of the sea storm, compared with the predictions by more sophisticated atmosphere-ocean numerical models. In particular, the obtained value of H_s, equal to 6.58 m, makes the investigated sea storm an exceptional event.