Donut Island Surf Stats

The rose diagram illustrates the range of swells directed at Donut Island through an average August and is based upon 2975 NWW3 model predictions since 2006 (values every 3 hours). The wave model does not forecast wind and surf right at the coast so we have chosen the optimum grid node based on what we know about Donut Island. In this particular case the best grid node is 26 km away (16 miles). The rose diagram shows the distribution of swell sizes and directions, while the graph at the bottom shows the same thing without 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 55% of the time. Green and yellow represent increasing swell sizes and red illustrates largest swells greater than >3m (>10ft). In either graph, the area of any colour is proportional to how frequently that size swell was forecast. The diagram suggests that the most common swell direction, shown by the largest spokes, was NE, whereas the the most common wind blows from the W. Because the wave model grid is offshore, sometimes a strong offshore wind blows largest waves away from Donut Island and away from the coast. We combine these with the no surf category of the bar chart. To avoid confusion we don't show these in the rose diagram. Because wind determines whether or not waves are surfable at Donut Island, you can select a similar diagram that shows only the swells that were forecast to coincide with glassy or offshore wind conditions. In a typical August, swells large enough to cause good for surfing waves at Donut Island run for about 45% of the time.

read more