Otago Peninsula - Sandfly Bay Surf Stats

This image describes the combination of swells directed at Otago Peninsula - Sandfly Bay over a normal May, based on 3422 NWW3 model predictions since 2007 (values every 3 hours). The wave model does not forecast wind and surf right at the shore so we have chosen the best grid node based on what we know about Otago Peninsula - Sandfly Bay, and at Otago Peninsula - Sandfly Bay the best grid node is 16 km away (10 miles). The rose diagram describes the distribution of swell directions and swell sizes, 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 30% of the time. Green and yellow show increasing swell sizes and red illustrates the highest swells, greater than >3m (>10ft). In both graphs, the area of any colour is proportional to how frequently that size swell was forecast. The diagram suggests that the most common swell direction, shown by the longest spokes, was S, whereas the the dominant wind blows from the WNW. Because the wave model grid is away from the coast, sometimes a strong offshore wind blows largest waves away from Otago Peninsula - Sandfly Bay and out to sea. We lump these in with the no surf category of the bar chart. To avoid confusion we don't show these in the rose plot. Because wind determines whether or not waves are good for surfing at Otago Peninsula - Sandfly Bay, you can view an alternative image that shows only the swells that were forecast to coincide with glassy or offshore wind conditions. During a typical May, swells large enough to cause clean enough to surf waves at Otago Peninsula - Sandfly Bay run for about 70% of the time.

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