The South Jetty Surf Stats

This picture describes the combination of swells directed at The South Jetty through a typical June. It is based on 3384 NWW3 model predictions since 2006 (values every 3 hours). The wave model does not forecast wind or surf right at the coast so we have chosen the most applicable grid node based on what we know about The South Jetty. In the case of The South Jetty, the best grid node is 36 km away (22 miles). The rose diagram illustrates the distribution of swell sizes and swell direction, while the graph at the bottom shows the same thing 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 11% of the time. Green and yellow show increasing swell sizes and red shows highest swells greater than >3m (>10ft). In both graphs, the area of any colour is proportional to how frequently that size swell was forecast. The diagram suggests that the most common swell direction, shown by the longest spokes, was SE, whereas the the dominant wind blows from the SW. Because the wave model grid is away from the coast, sometimes a strong offshore wind blows largest waves away from The South Jetty and out to sea. We combine these 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 clean enough to surf at The South Jetty, you can view an alternative image that shows only the swells that were predicted to coincide with glassy or offshore wind conditions. Over an average June, swells large enough to cause surfable waves at The South Jetty run for about 89% of the time.

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