Dunedin - St Clair Surf Stats

The graph describes the combination of swells directed at Dunedin - St Clair through an average October, 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 Dunedin - St Clair, and at Dunedin - St Clair the best grid node is 10 km away (6 miles). The rose diagram illustrates the distribution of swell sizes and swell direction, 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 22% of the time. Green and yellow show increasing swell sizes and red shows 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 biggest spokes, was S, whereas the the dominant wind blows from the WNW. Because the wave model grid is out to sea, sometimes a strong offshore wind blows largest waves away from Dunedin - St Clair and offshore. We lump these in 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 good for surfing at Dunedin - St Clair, you can load a different image that shows only the swells that were expected to coincide with glassy or offshore wind conditions. In a typical October, swells large enough to cause clean enough to surf waves at Dunedin - St Clair run for about 78% of the time.

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