Tahunanui bar Surf Stats

The rose diagram shows the range of swells directed at Tahunanui bar through an average September, based on 2880 NWW3 model predictions since 2008 (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 Tahunanui bar, and at Tahunanui bar the best grid node is 36 km away (22 miles). The rose diagram illustrates the distribution of swell directions and swell sizes, while the graph at the bottom shows the same thing but without direction information. Five colours show increasing wave sizes. The smallest swells, less than 0.5m (1.5 feet), high are coloured blue. These occurred 53% of the time. Green and yellow show increasing swell sizes and red illustrates the biggest swells, greater than >3m (>10ft). In either graph, the area of any colour is proportional to how frequently that size swell occurs. The diagram suggests that the most common swell direction, shown by the biggest spokes, was NNW, whereas the the prevailing wind blows from the W. Because the wave model grid is away from the coast, sometimes a strong offshore wind blows largest waves away from Tahunanui bar 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 diagram. Because wind determines whether or not waves are surfable at Tahunanui bar, you can load a different image that shows only the swells that were predicted to coincide with glassy or offshore wind conditions. In a typical September, swells large enough to cause good for surfing waves at Tahunanui bar run for about 23% of the time.

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