Birling Gap Surf Stats

The figure shows the combination of swells directed at Birling Gap through a typical November. It is based on 3343 NWW3 model predictions since 2006 (values every 3 hours). The wave model does not forecast wind and surf right at the coast so we have chosen the optimum grid node based on what we know about Birling Gap. In this particular case the best grid node is 31 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 show increasing wave sizes. The smallest swells, less than 0.5m (1.5 feet), high are coloured blue. These were forecast only 41% of the time. Green and yellow show increasing swell sizes and red shows biggest swells greater than >3m (>10ft). In both graphs, 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 largest spokes, was SW, whereas the the prevailing wind blows from the WSW. Because the wave model grid is offshore, sometimes a strong offshore wind blows largest waves away from Birling Gap 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 Birling Gap, you can select a similar diagram that shows only the swells that were predicted to coincide with glassy or offshore wind conditions. Over an average November, swells large enough to cause surfable waves at Birling Gap run for about 41% of the time.

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