Statistiques de Surf de Hapuna

The figure describes the variation of swells directed at Hapuna over a normal August. It is based on 3582 NWW3 model predictions since 2006 (values every 3 hours). The wave model does not forecast surf and wind right at the coastline so we have chosen the most applicable grid node based on what we know about Hapuna, and at Hapuna the best grid node is 18 km away (11 miles). The rose diagram shows the distribution of swell directions and swell sizes, while the graph at the bottom shows the same thing without direction information. Five colours illustrate increasing wave sizes. Blue shows the smallest swells, less that 0.5m (1.5 feet) high. These were forecast only 56% of the time. Green and yellow illustrate increasing swell sizes and red represents the highest swells, greater than >3m (>10ft). In both graphs, the area of any colour is proportional to how often that size swell occurs. The diagram indicates that the prevailing swell direction, shown by the longest spokes, was WSW, whereas the the dominant wind blows from the NNE. Because the wave model grid is offshore, sometimes a strong offshore wind blows largest waves away from Hapuna and away from the coast. We group these with the no surf category of the bar chart. To keep it simple we don't show these in the rose plot. Because wind determines whether or not waves are clean enough to surf at Hapuna, you can view an alternative image that shows only the swells that were forecast to coincide with glassy or offshore wind conditions. During a typical August, swells large enough to cause surfable waves at Hapuna run for about 1.0% of the time.

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