Bruny Island - Mabel Bay Surf Stats

This image shows the combination of swells directed at Bruny Island - Mabel Bay over a normal May. It is based on 3414 NWW3 model predictions since 2007 (values every 3 hours). The wave model does not forecast wind or surf right at the coast so we have chosen the optimum grid node based on what we know about Bruny Island - Mabel Bay, and at Bruny Island - Mabel Bay the best grid node is 13 km away (8 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 illustrate increasing wave sizes. Blue shows the smallest swells, less that 0.5m (1.5 feet) high. These were forecast only 8% of the time. Green and yellow represent increasing swell sizes and red represents the biggest swells, greater than >3m (>10ft). In each graph, the area of any colour is proportional to how frequently that size swell happens. The diagram suggests that the prevailing swell direction, shown by the longest spokes, was SSW, whereas the the prevailing wind blows from the WNW. Because the wave model grid is away from the coast, sometimes a strong offshore wind blows largest waves away from Bruny Island - Mabel Bay and out to sea. 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 - Mabel Bay, 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 May, swells large enough to cause surfable waves at Bruny Island - Mabel Bay run for about 92% of the time.

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