Llangennith Surf Stats

The figure shows the range of swells directed at Llangennith over a normal October and is based upon 3471 NWW3 model predictions since 2006 (values every 3 hours). The wave model does not forecast surf and wind right at the shore so we have chosen the best grid node based on what we know about Llangennith. In this particular case the best grid node is 17 km away (11 miles). The rose diagram shows the distribution of swell sizes and directions, while the graph at the bottom shows the same thing but 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 17% of the time. Green and yellow represent increasing swell sizes and red illustrates biggest swells greater than >3m (>10ft). In either graph, the area of any colour is proportional to how commonly that size swell was forecast. The diagram implies that the most common swell direction, shown by the biggest spokes, was WSW, whereas the the prevailing wind blows from the SW. Because the wave model grid is offshore, sometimes a strong offshore wind blows largest waves away from Llangennith and away from the coast. We lump these in with the no surf category of the bar chart. To simplify things we don't show these in the rose graph. Because wind determines whether or not waves are surfable at Llangennith, you can view an alternative image that shows only the swells that were expected to coincide with glassy or offshore wind conditions. During a typical October, swells large enough to cause good for surfing waves at Llangennith run for about 83% of the time.

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