Seaford Reef Surf Stats

The figure describes the combination of swells directed at Seaford Reef through a typical April, based on 3360 NWW3 model predictions since 2007 (values every 3 hours). The wave model does not forecast surf and wind right at the shore so we have chosen the optimum grid node based on what we know about Seaford Reef. In the case of Seaford Reef, the best grid node is 55 km away (34 miles). The rose diagram illustrates the distribution of swell sizes and directions, while the graph at the bottom shows the same thing but lacks direction information. Five colours show increasing wave sizes. The smallest swells, less than 0.5m (1.5 feet), high are coloured blue. These happened only 90% of the time. Green and yellow show increasing swell sizes and highest swells greater than >3m (>10ft) are shown in red. In either graph, the area of any colour is proportional to how commonly that size swell was forecast. The diagram implies that the prevailing swell direction, shown by the longest spokes, was WSW, whereas the the dominant wind blows from the SSE. Because the wave model grid is offshore, sometimes a strong offshore wind blows largest waves away from Seaford Reef and away from the coast. We combine these with the no surf category of the bar chart. To keep it simple we don't show these in the rose diagram. Because wind determines whether or not waves are clean enough to surf at Seaford Reef, you can view an alternative image that shows only the swells that were predicted to coincide with glassy or offshore wind conditions. Over an average April, swells large enough to cause surfable waves at Seaford Reef run for about 1.0% of the time.

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