Jap Rock Surf Stats

This picture illustrates the range of swells directed at Jap Rock over a normal August and is based upon 3582 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 Jap Rock, and at Jap Rock the best grid node is 14 km away (9 miles). The rose diagram shows the distribution of swell sizes and swell direction, while the graph at the bottom shows the same thing but lacks 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 were forecast 58% of the time. Green and yellow show increasing swell sizes and red shows the largest swells, greater than >3m (>10ft). In both graphs, the area of any colour is proportional to how frequently that size swell occurs. The diagram suggests that the dominant swell direction, shown by the longest spokes, was E, whereas the the most common 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 Jap Rock 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 diagram. Because wind determines whether or not waves are good for surfing at Jap Rock, you can select a similar diagram that shows only the swells that were forecast to coincide with glassy or offshore wind conditions. During a typical August, swells large enough to cause clean enough to surf waves at Jap Rock run for about 42% of the time.

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