Riversdale Surf Stats

The figure describes the range of swells directed at Riversdale through an average September. It is based on 3360 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 Riversdale, and at Riversdale the best grid node is 38 km away (24 miles). The rose diagram describes 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 occurred only 43% of the time. Green and yellow illustrate increasing swell sizes and red illustrates highest swells greater than >3m (>10ft). In each graph, the area of any colour is proportional to how often that size swell was forecast. The diagram indicates that the prevailing swell direction, shown by the longest spokes, was SE, whereas the the dominant wind blows from the WNW. Because the wave model grid is offshore, sometimes a strong offshore wind blows largest waves away from Riversdale and away from the coast. We group these with the no surf category of the bar chart. To avoid confusion we don't show these in the rose graph. Because wind determines whether or not waves are clean enough to surf at Riversdale, you can view an alternative image that shows only the swells that were expected to coincide with glassy or offshore wind conditions. In a typical September, swells large enough to cause surfable waves at Riversdale run for about 57% of the time.

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