Milnerton Surf Stats

This picture describes the combination of swells directed at Milnerton through an average October. It is based on 3471 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 most applicable grid node based on what we know about Milnerton. In this particular case the best grid node is 48 km away (30 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 illustrate increasing wave sizes. Blue shows the smallest swells, less that 0.5m (1.5 feet) high. These happened only 7% of the time. Green and yellow represent increasing swell sizes and red represents the highest swells, greater than >3m (>10ft). In each graph, the area of any colour is proportional to how frequently that size swell happens. The diagram suggests that the prevailing swell direction, shown by the longest spokes, was SW, whereas the the dominant wind blows from the SSW. Because the wave model grid is out to sea, sometimes a strong offshore wind blows largest waves away from Milnerton and offshore. We combine 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 Milnerton, you can select a similar diagram that shows only the swells that were predicted to coincide with glassy or offshore wind conditions. In a typical October, swells large enough to cause clean enough to surf waves at Milnerton run for about 89% of the time.

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