Southend Reef Surf Stats

The rose diagram illustrates the range of swells directed at Southend Reef through a typical October, based on 2975 NWW3 model predictions since 2008 (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 Southend Reef, and at Southend Reef the best grid node is 32 km away (20 miles). The rose diagram describes the distribution of swell directions and swell sizes, while the graph at the bottom shows the same thing 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 71% of the time. Green and yellow illustrate increasing swell sizes and red illustrates largest swells greater than >3m (>10ft). In both graphs, the area of any colour is proportional to how commonly that size swell happens. The diagram implies that the most common swell direction, shown by the longest spokes, was S, whereas the the most common wind blows from the SSW. Because the wave model grid is away from the coast, sometimes a strong offshore wind blows largest waves away from Southend Reef and out to sea. We combine these with the no surf category of the bar chart. To simplify things we don't show these in the rose graph. Because wind determines whether or not waves are clean enough to surf 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 October, swells large enough to cause surfable waves at Southend Reef run for about 29% of the time.

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