Shelly Beach Surf Stats

The rose diagram describes the range of swells directed at Shelly Beach through a typical September. It is based on 3360 NWW3 model predictions since 2006 (values every 3 hours). The wave model does not forecast wind or surf right at the shore so we have chosen the best grid node based on what we know about Shelly Beach, and at Shelly Beach the best grid node is 45 km away (28 miles). The rose diagram describes the distribution of swell sizes and directions, 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 happened only 21% of the time. Green and yellow show increasing swell sizes and highest swells greater than >3m (>10ft) are shown in red. 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 longest spokes, was SE, whereas the the dominant wind blows from the N. Because the wave model grid is out to sea, sometimes a strong offshore wind blows largest waves away from Shelly Beach and offshore. We lump these in with the no surf category of the bar chart. To simplify things we don't show these in the rose plot. Because wind determines whether or not waves are clean enough to surf at Shelly Beach, you can select a similar diagram that shows only the swells that were predicted to coincide with glassy or offshore wind conditions. Over an average September, swells large enough to cause surfable waves at Shelly Beach run for about 79% of the time.

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