Portreath Harbour Wall Surf Stats

This image illustrates the combination of swells directed at Portreath Harbour Wall through a typical September, based on 3360 NWW3 model predictions since 2006 (values every 3 hours). The wave model does not forecast wind or surf right at the shore so we have chosen the optimum grid node based on what we know about Portreath Harbour Wall, and at Portreath Harbour Wall the best grid node is 30 km away (19 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 illustrate increasing wave sizes. Blue shows the smallest swells, less that 0.5m (1.5 feet) high. These occurred only 18% of the time. Green and yellow represent increasing swell sizes and red shows largest swells greater than >3m (>10ft). In either graph, the area of any colour is proportional to how frequently that size swell was forecast. The diagram suggests that the dominant swell direction, shown by the longest spokes, was WNW, whereas the the most common wind blows from the W. Because the wave model grid is away from the coast, sometimes a strong offshore wind blows largest waves away from Portreath Harbour Wall 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 Portreath Harbour Wall, 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 September, swells large enough to cause clean enough to surf waves at Portreath Harbour Wall run for about 49% of the time.

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