Birdrock Surf Stats

This picture describes the variation of swells directed at Birdrock over a normal April and is based upon 3360 NWW3 model predictions since 2007 (values every 3 hours). The wave model does not forecast wind or surf right at the coastline so we have chosen the best grid node based on what we know about Birdrock. In the case of Birdrock, the best grid node is 29 km away (18 miles). The rose diagram illustrates the distribution of swell directions and swell sizes, while the graph at the bottom shows the same thing 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 63% of the time. Green and yellow show increasing swell sizes and red represents highest 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 biggest spokes, was WSW (which was the same as the dominant wind direction). Because the wave model grid is away from the coast, sometimes a strong offshore wind blows largest waves away from Birdrock and out to sea. We lump these in with the no surf category of the bar chart. To avoid confusion we don't show these in the rose plot. Because wind determines whether or not waves are clean enough to surf at Birdrock, 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 April, swells large enough to cause surfable waves at Birdrock run for about 37% of the time.

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