South Stradbroke Surf Stats

The rose diagram shows the combination of swells directed at South Stradbroke through an average February and is based upon 3120 NWW3 model predictions since 2007 (values every 3 hours). The wave model does not forecast wind and surf right at the shore so we have chosen the optimum grid node based on what we know about South Stradbroke, and at South Stradbroke the best grid node is 11 km away (7 miles). The rose diagram describes the distribution of swell sizes and swell direction, while the graph at the bottom shows the same thing but lacks direction information. Five colours show increasing wave sizes. The smallest swells, less than 0.5m (1.5 feet), high are coloured blue. These happened only 4% of the time. Green and yellow represent increasing swell sizes and red shows the biggest swells, greater than >3m (>10ft). In either graph, the area of any colour is proportional to how often that size swell occurs. The diagram indicates that the dominant swell direction, shown by the longest spokes, was E, whereas the the prevailing wind blows from the ESE. Because the wave model grid is offshore, sometimes a strong offshore wind blows largest waves away from South Stradbroke and away from the coast. We combine these with the no surf category of the bar chart. To keep it simple we don't show these in the rose diagram. Because wind determines whether or not waves are surfable at South Stradbroke, you can view an alternative image that shows only the swells that were expected to coincide with glassy or offshore wind conditions. In a typical February, swells large enough to cause good for surfing waves at South Stradbroke run for about 96% of the time.

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