North Jetty Surf Stats

The graph describes the combination of swells directed at North Jetty over a normal May, based on 2838 NWW3 model predictions since 2007 (values every 3 hours). The wave model does not forecast wind and surf right at the coastline so we have chosen the most applicable grid node based on what we know about North Jetty, and at North Jetty the best grid node is 40 km away (25 miles). The rose diagram shows the distribution of swell sizes and swell direction, while the graph at the bottom shows the same thing without direction information. Five colours show increasing wave sizes. The smallest swells, less than 0.5m (1.5 feet), high are coloured blue. These occurred only 52% of the time. Green and yellow illustrate 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 was forecast. The diagram indicates that the prevailing swell direction, shown by the biggest spokes, was ENE, whereas the the dominant wind blows from the SE. Because the wave model grid is away from the coast, sometimes a strong offshore wind blows largest waves away from North Jetty and out to sea. We lump these in with the no surf category of the bar chart. To simplify things we don't show these in the rose graph. Because wind determines whether or not waves are good for surfing at North Jetty, 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 May, swells large enough to cause clean enough to surf waves at North Jetty run for about 48% of the time.

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