Kahuku Ranch Surf Stats

This chart illustrates the variation of swells directed at Kahuku Ranch through an average August, based on 3582 NWW3 model predictions since 2006 (values every 3 hours). The wave model does not forecast wind and surf right at the shore so we have chosen the most applicable grid node based on what we know about Kahuku Ranch, and at Kahuku Ranch the best grid node is 22 km away (14 miles). The rose diagram shows 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 happened only 83% of the time. Green and yellow represent increasing swell sizes and red represents largest swells greater than >3m (>10ft). In each graph, the area of any colour is proportional to how frequently that size swell occurs. The diagram suggests that the prevailing swell direction, shown by the biggest spokes, was SSW, whereas the the most common wind blows from the ENE. Because the wave model grid is out to sea, sometimes a strong offshore wind blows largest waves away from Kahuku Ranch 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 plot. Because wind determines whether or not waves are clean enough to surf at Kahuku Ranch, you can load a different image 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 surfable waves at Kahuku Ranch run for about 17% of the time.

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