Derrynane Surf Stats

This chart illustrates the range of swells directed at Derrynane through a typical July, based on 2976 NWW3 model predictions since 2006 (values every 3 hours). The wave model does not forecast surf and wind right at the coastline so we have chosen the optimum grid node based on what we know about Derrynane. In this particular case the best grid node is 31 km away (19 miles). The rose diagram describes 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 occurred only 53% of the time. Green and yellow represent increasing swell sizes and red illustrates the largest swells, greater than >3m (>10ft). In either graph, the area of any colour is proportional to how often that size swell was forecast. The diagram indicates that the most common swell direction, shown by the biggest spokes, was WSW (which was the same as the most common wind direction). Because the wave model grid is away from the coast, sometimes a strong offshore wind blows largest waves away from Derrynane and out to sea. We group these 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 surfable at Derrynane, you can load a different image that shows only the swells that were expected to coincide with glassy or offshore wind conditions. Over an average July, swells large enough to cause good for surfing waves at Derrynane run for about 33% of the time.

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