Southend Reef Surf Stats

This picture illustrates the variation of swells directed at Southend Reef through a typical July. It is based on 2976 NWW3 model predictions since 2008 (values every 3 hours). The wave model does not forecast wind and surf right at the coast so we have chosen the best grid node based on what we know about Southend Reef, and at Southend Reef the best grid node is 32 km away (20 miles). The rose diagram describes 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 84% of the time. Green and yellow represent increasing swell sizes and red represents largest swells greater than >3m (>10ft). In both graphs, the area of any colour is proportional to how often that size swell happens. The diagram indicates that the prevailing swell direction, shown by the largest spokes, was S, whereas the the most common wind blows from the WSW. Because the wave model grid is out to sea, sometimes a strong offshore wind blows largest waves away from Southend Reef and offshore. We lump these in with the no surf category of the bar chart. To avoid confusion we don't show these in the rose diagram. Because wind determines whether or not waves are surfable at Southend Reef, you can select a similar diagram that shows only the swells that were expected to coincide with glassy or offshore wind conditions. Over an average July, swells large enough to cause good for surfing waves at Southend Reef run for about 16% of the time.

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