Narrabeen-Alley Rights Surf Stats

The figure illustrates the range of swells directed at Narrabeen-Alley Rights over a normal August, based on 2976 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 optimum grid node based on what we know about Narrabeen-Alley Rights. In the case of Narrabeen-Alley Rights, the best grid node is 29 km away (18 miles). The rose diagram illustrates the distribution of swell sizes and swell direction, while the graph at the bottom shows the same thing but lacks direction information. Five colours illustrate increasing wave sizes. Blue shows the smallest swells, less that 0.5m (1.5 feet) high. These were forecast only 71% of the time. Green and yellow illustrate increasing swell sizes and red illustrates largest swells greater than >3m (>10ft). In either graph, the area of any colour is proportional to how often that size swell happens. The diagram indicates that the dominant swell direction, shown by the biggest spokes, was E, whereas the the most common wind blows from the W. Because the wave model grid is offshore, sometimes a strong offshore wind blows largest waves away from Narrabeen-Alley Rights and away from the coast. We group these 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 Narrabeen-Alley Rights, you can view an alternative image 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 Narrabeen-Alley Rights run for about 29% of the time.

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