Kapoho Bay Surf Stats

The rose diagram describes the range of swells directed at Kapoho Bay through a typical June and is based upon 3506 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 Kapoho Bay, and at Kapoho Bay the best grid node is 33 km away (21 miles). The rose diagram shows the distribution of swell sizes and swell direction, 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 were forecast only 37% of the time. Green and yellow illustrate increasing swell sizes and red shows the highest swells, greater than >3m (>10ft). In either graph, the area of any colour is proportional to how often that size swell was forecast. The diagram indicates that the prevailing swell direction, shown by the longest spokes, was ESE, whereas the the dominant wind blows from the ENE. Because the wave model grid is offshore, sometimes a strong offshore wind blows largest waves away from Kapoho Bay and away from the coast. We group 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 good for surfing at Kapoho Bay, you can select a similar diagram that shows only the swells that were forecast to coincide with glassy or offshore wind conditions. Over an average June, swells large enough to cause clean enough to surf waves at Kapoho Bay run for about 63% of the time.

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