South Moana Reefs Surf Stats

The graph illustrates the range of swells directed at South Moana Reefs through a typical August and is based upon 3472 NWW3 model predictions since 2006 (values every 3 hours). The wave model does not forecast wind and surf right at the coast so we have chosen the optimum grid node based on what we know about South Moana Reefs. In this particular case the best grid node is 53 km away (33 miles). The rose diagram shows the distribution of swell sizes and directions, while the graph at the bottom shows the same thing but without direction information. Five colours show increasing wave sizes. The smallest swells, less than 0.5m (1.5 feet), high are coloured blue. These were forecast only 70% of the time. Green and yellow represent increasing swell sizes and red shows the largest swells, greater than >3m (>10ft). In each 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 WSW, whereas the the most common wind blows from the WNW. Because the wave model grid is offshore, sometimes a strong offshore wind blows largest waves away from South Moana Reefs and away from the coast. We group these with the no surf category of the bar chart. To keep it simple we don't show these in the rose graph. Because wind determines whether or not waves are clean enough to surf at South Moana Reefs, you can load a different image that shows only the swells that were expected to coincide with glassy or offshore wind conditions. Over an average August, swells large enough to cause surfable waves at South Moana Reefs run for about 5% of the time.

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