Kahalu'u Beach Park Surf Stats

This chart illustrates the range of swells directed at Kahalu'u Beach Park through an average May. It is based on 3440 NWW3 model predictions since 2007 (values every 3 hours). The wave model does not forecast wind and surf right at the coast so we have chosen the best grid node based on what we know about Kahalu'u Beach Park, and at Kahalu'u Beach Park the best grid node is 9 km away (6 miles). The rose diagram describes the distribution of swell sizes and directions, 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 were forecast only 10% of the time. Green and yellow illustrate increasing swell sizes and red represents the largest swells, greater than >3m (>10ft). In each graph, the area of any colour is proportional to how commonly that size swell occurs. The diagram implies that the dominant swell direction, shown by the longest spokes, was SSW, whereas the the most common wind blows from the WNW. Because the wave model grid is out to sea, sometimes a strong offshore wind blows largest waves away from Kahalu'u Beach Park and offshore. 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 Kahalu'u Beach Park, 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 May, swells large enough to cause good for surfing waves at Kahalu'u Beach Park run for about 90% of the time.

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