Dumpers Surf Stats

The graph describes the variation of swells directed at Dumpers through an average September, based on 2880 NWW3 model predictions since 2006 (values every 3 hours). The wave model does not forecast surf and wind right at the coastline so we have chosen the best grid node based on what we know about Dumpers, and at Dumpers the best grid node is 29 km away (18 miles). The rose diagram describes the distribution of swell directions and swell sizes, while the graph at the bottom shows the same thing but lacks 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 occurred 16% of the time. Green and yellow show increasing swell sizes and red represents highest swells greater than >3m (>10ft). In each graph, the area of any colour is proportional to how commonly that size swell happens. The diagram implies that the prevailing swell direction, shown by the biggest spokes, was ENE, whereas the the dominant wind blows from the NW. Because the wave model grid is offshore, sometimes a strong offshore wind blows largest waves away from Dumpers 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 plot. Because wind determines whether or not waves are surfable at Dumpers, you can select a similar diagram that shows only the swells that were forecast to coincide with glassy or offshore wind conditions. In a typical September, swells large enough to cause good for surfing waves at Dumpers run for about 84% of the time.

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