Statistiques de Surf de St Joe s Island

The rose diagram describes the combination of swells directed at St Joe s Island through an average November and is based upon 3346 NWW3 model predictions since 2006 (values every 3 hours). The wave model does not forecast surf and wind right at the coast so we have chosen the best grid node based on what we know about St Joe s Island. In this particular case the best grid node is 38 km away (24 miles). The rose diagram describes the distribution of swell sizes and swell direction, while the graph at the bottom shows the same thing without direction information. Five colours illustrate increasing wave sizes. Blue shows the smallest swells, less that 0.5m (1.5 feet) high. These happened only 25% of the time. Green and yellow represent increasing swell sizes and red shows highest swells greater than >3m (>10ft). In both graphs, the area of any colour is proportional to how often that size swell occurs. The diagram indicates that the dominant swell direction, shown by the longest spokes, was ESE, whereas the the dominant wind blows from the E. Because the wave model grid is offshore, sometimes a strong offshore wind blows largest waves away from St Joe s Island and away from the coast. We combine these with the no surf category of the bar chart. To avoid confusion we don't show these in the rose graph. Because wind determines whether or not waves are clean enough to surf at St Joe s Island, you can select a similar diagram that shows only the swells that were forecast to coincide with glassy or offshore wind conditions. In a typical November, swells large enough to cause surfable waves at St Joe s Island run for about 75% of the time.

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