Llanddulas Breakwater Surf Stats

The graph shows the combination of swells directed at Llanddulas Breakwater through a typical May. It is based on 3155 NWW3 model predictions since 2008 (values every 3 hours). The wave model does not forecast wind and surf right at the coast so we have chosen the best grid node based on what we know about Llanddulas Breakwater. 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 represent increasing wave sizes. Very small swells of less than 0.5m (1.5 feet) high are shown in blue. These happened 82% of the time. Green and yellow represent increasing swell sizes and red shows biggest swells greater than >3m (>10ft). In both graphs, 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 largest spokes, was NW, whereas the the prevailing wind blows from the WSW. Because the wave model grid is out to sea, sometimes a strong offshore wind blows largest waves away from Llanddulas Breakwater and offshore. 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 good for surfing at Llanddulas Breakwater, 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 May, swells large enough to cause clean enough to surf waves at Llanddulas Breakwater run for about 4% of the time.

read more