San Jose Island Surf Stats

The rose diagram illustrates the variation of swells directed at San Jose Island through a typical October. It is based on 3470 NWW3 model predictions since 2006 (values every 3 hours). The wave model does not forecast wind and surf right at the shore so we have chosen the best grid node based on what we know about San Jose Island. In the case of San Jose Island, the best grid node is 47 km away (29 miles). The rose diagram shows the distribution of swell sizes and directions, while the graph at the bottom shows the same thing but without direction information. Five colours illustrate increasing wave sizes. Blue shows the smallest swells, less that 0.5m (1.5 feet) high. These occurred only 20% of the time. Green and yellow show increasing swell sizes and largest swells greater than >3m (>10ft) are shown in red. In either graph, 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 biggest spokes, was ESE, whereas the the most common wind blows from the E. Because the wave model grid is offshore, sometimes a strong offshore wind blows largest waves away from San Jose Island and away from the coast. We lump these in with the no surf category of the bar chart. To keep it simple we don't show these in the rose diagram. Because wind determines whether or not waves are surfable at San Jose Island, you can select a similar diagram that shows only the swells that were forecast to coincide with glassy or offshore wind conditions. Over an average October, swells large enough to cause good for surfing waves at San Jose Island run for about 80% of the time.

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