Statistiques de Surf de Dahomey

The figure describes the variation of swells directed at Dahomey over a normal August. It is based on 2976 NWW3 model predictions since 2006 (values every 3 hours). The wave model does not forecast surf and wind right at the shore so we have chosen the optimum grid node based on what we know about Dahomey. In the case of Dahomey, the best grid node is 31 km away (19 miles). The rose diagram describes the distribution of swell sizes and directions, while the graph at the bottom shows the same thing but without direction information. Five colours represent increasing wave sizes. Very small swells of less than 0.5m (1.5 feet) high are shown in blue. These happened only 0.5% of the time. Green and yellow represent increasing swell sizes and red represents highest swells greater than >3m (>10ft). In both graphs, the area of any colour is proportional to how commonly that size swell occurs. The diagram implies that the prevailing swell direction, shown by the largest spokes, was NW, whereas the the dominant wind blows from the NNW. Because the wave model grid is offshore, sometimes a strong offshore wind blows largest waves away from Dahomey and away from the coast. We lump these in with the no surf category of the bar chart. To simplify things we don't show these in the rose plot. Because wind determines whether or not waves are clean enough to surf at Dahomey, you can select a similar diagram that shows only the swells that were predicted to coincide with glassy or offshore wind conditions. During a typical August, swells large enough to cause surfable waves at Dahomey run for about 32% of the time.

read more