Perran Sands Surf Stats

The graph describes the combination of swells directed at Perran Sands over a normal November and is based upon 3107 NWW3 model predictions since 2006 (values every 3 hours). The wave model does not forecast surf and wind right at the shore so we have chosen the most applicable grid node based on what we know about Perran Sands. In the case of Perran Sands, the best grid node is 29 km away (18 miles). The rose diagram describes the distribution of swell sizes and directions, while the graph at the bottom shows the same thing without direction information. Five colours represent increasing wave sizes. Very small swells of less than 0.5m (1.5 feet) high are shown in blue. These were forecast only 13% of the time. Green and yellow represent increasing swell sizes and red shows the highest 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 prevailing swell direction, shown by the longest spokes, was W (which was the same as the dominant wind direction). Because the wave model grid is away from the coast, sometimes a strong offshore wind blows largest waves away from Perran Sands and out to sea. We group these with the no surf category of the bar chart. To keep it simple we don't show these in the rose graph. Because wind determines whether or not waves are good for surfing at Perran Sands, you can select a similar diagram that shows only the swells that were predicted to coincide with glassy or offshore wind conditions. During a typical November, swells large enough to cause clean enough to surf waves at Perran Sands run for about 70% of the time.

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