TCs Surf Stats

The rose diagram illustrates the variation of swells directed at TCs over a normal July, based on 3472 NWW3 model predictions since 2006 (values every 3 hours). The wave model does not forecast surf and wind right at the coast so we have chosen the best grid node based on what we know about TCs. In the case of TCs, 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 show increasing wave sizes. The smallest swells, less than 0.5m (1.5 feet), high are coloured blue. These happened only 4% of the time. Green and yellow show increasing swell sizes and red represents largest swells greater than >3m (>10ft). In either graph, the area of any colour is proportional to how often that size swell was forecast. The diagram indicates that the dominant swell direction, shown by the biggest spokes, was SSW, whereas the the most common wind blows from the SW. Because the wave model grid is away from the coast, sometimes a strong offshore wind blows largest waves away from TCs and out to sea. We group these 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 clean enough to surf at TCs, you can view an alternative image that shows only the swells that were predicted to coincide with glassy or offshore wind conditions. During a typical July, swells large enough to cause surfable waves at TCs run for about 96% of the time.

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