Dunbar/Belhaven Bay Surf Stats

The rose diagram illustrates the variation of swells directed at Dunbar/Belhaven Bay through a typical May. It is based on 2838 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 Dunbar/Belhaven Bay. In this particular case the best grid node is 33 km away (21 miles). The rose diagram shows the distribution of swell sizes and directions, 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 50% of the time. Green and yellow represent increasing swell sizes and red represents the largest swells, greater than >3m (>10ft). In each graph, the area of any colour is proportional to how often that size swell happens. The diagram indicates that the dominant swell direction, shown by the biggest spokes, was NE, whereas the the most common wind blows from the S. Because the wave model grid is offshore, sometimes a strong offshore wind blows largest waves away from Dunbar/Belhaven Bay and away from the coast. We combine 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 Dunbar/Belhaven Bay, you can view an alternative image that shows only the swells that were predicted to coincide with glassy or offshore wind conditions. Over an average May, swells large enough to cause clean enough to surf waves at Dunbar/Belhaven Bay run for about 14% of the time.

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