Bruny Island - Jawbones Surf Stats

The graph describes the variation of swells directed at Bruny Island - Jawbones over a normal October, based on 3471 NWW3 model predictions since 2006 (values every 3 hours). The wave model does not forecast wind and surf right at the coastline so we have chosen the best grid node based on what we know about Bruny Island - Jawbones, and at Bruny Island - Jawbones the best grid node is 17 km away (11 miles). The rose diagram describes the distribution of swell directions and swell sizes, while the graph at the bottom shows the same thing but without 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 only 32% of the time. Green and yellow show increasing swell sizes and red illustrates the highest swells, greater than >3m (>10ft). In either graph, the area of any colour is proportional to how commonly that size swell occurs. The diagram implies that the prevailing swell direction, shown by the largest spokes, was SSW, 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 Bruny Island - Jawbones 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 clean enough to surf at Bruny Island - Jawbones, you can select a similar diagram that shows only the swells that were forecast to coincide with glassy or offshore wind conditions. During a typical October, swells large enough to cause surfable waves at Bruny Island - Jawbones run for about 68% of the time.

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