Bronte Beach Surf Stats

This picture shows the variation of swells directed at Bronte Beach over a normal June. It is based on 3506 NWW3 model predictions since 2006 (values every 3 hours). The wave model does not forecast wind and surf right at the shore so we have chosen the most applicable grid node based on what we know about Bronte Beach, and at Bronte Beach the best grid node is 23 km away (14 miles). The rose diagram illustrates the distribution of swell sizes and swell direction, while the graph at the bottom shows the same thing but lacks 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 happened only 15% of the time. Green and yellow illustrate increasing swell sizes and red represents the biggest swells, greater than >3m (>10ft). In either graph, the area of any colour is proportional to how often that size swell happens. The diagram indicates that the prevailing swell direction, shown by the longest spokes, was SE, whereas the the prevailing wind blows from the SW. Because the wave model grid is out to sea, sometimes a strong offshore wind blows largest waves away from Bronte Beach and offshore. We lump these in with the no surf category of the bar chart. To keep it simple we don't show these in the rose graph. Because wind determines whether or not waves are clean enough to surf at Bronte Beach, you can select a similar diagram that shows only the swells that were expected to coincide with glassy or offshore wind conditions. During a typical June, swells large enough to cause surfable waves at Bronte Beach run for about 85% of the time.

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