BBC Surf Stats

The graph shows the combination of swells directed at BBC through a typical June. It is based on 3506 NWW3 model predictions since 2006 (values every 3 hours). The wave model does not forecast surf and wind right at the coast so we have chosen the best grid node based on what we know about BBC. In this particular case the best grid node is 25 km away (16 miles). The rose diagram illustrates the distribution of swell sizes and swell direction, 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 happened only 12% of the time. Green and yellow represent increasing swell sizes and biggest swells greater than >3m (>10ft) are shown in red. In either graph, the area of any colour is proportional to how often that size swell happens. The diagram indicates that the most common swell direction, shown by the biggest spokes, was S, whereas the the prevailing wind blows from the SSW. Because the wave model grid is offshore, sometimes a strong offshore wind blows largest waves away from BBC and away from the coast. We lump these in with the no surf category of the bar chart. To avoid confusion we don't show these in the rose diagram. Because wind determines whether or not waves are clean enough to surf at BBC, 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 June, swells large enough to cause surfable waves at BBC run for about 84% of the time.

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