Directional Return Period of Severe Storms Off Italian Coasts

The paper proposes the directional analysis of the severest storms recorded by the Italian Wave Measurement Network (RON). For this purpose the buoy data have been processed and all the storms have been selected; for the strongest storms, the direction of the sea states, which form them, has been analyzed. The directional return period of sea storms in which the maximum significant wave height exceeds a threshold is then obtained, by applying the ETS model. It is found that, for the prediction of extreme storms off Italy, it is possible to assume the duration of storms constant, with an error smaller than 4%.