Statistiques de Surf de China Beach

This picture describes the combination of swells directed at China Beach over a normal August. It is based on 3472 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 optimum grid node based on what we know about China Beach. In this particular case the best grid node is 23 km away (14 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 show increasing wave sizes. The smallest swells, less than 0.5m (1.5 feet), high are coloured blue. These were forecast 76% of the time. Green and yellow show increasing swell sizes and red represents the highest swells, greater than >3m (>10ft). In each graph, the area of any colour is proportional to how frequently that size swell was forecast. The diagram suggests that the prevailing swell direction, shown by the largest spokes, was ENE, whereas the the dominant wind blows from the SSW. Because the wave model grid is offshore, sometimes a strong offshore wind blows largest waves away from China Beach and away from the coast. We lump these in with the no surf category of the bar chart. To keep it simple we don't show these in the rose diagram. Because wind determines whether or not waves are surfable at China Beach, you can load a different image that shows only the swells that were expected to coincide with glassy or offshore wind conditions. During a typical August, swells large enough to cause good for surfing waves at China Beach run for about 24% of the time.

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