Keaulanas Surf Stats

The figure describes the combination of swells directed at Keaulanas through a typical July, based on 3720 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 optimum grid node based on what we know about Keaulanas. In this particular case the best grid node is 39 km away (24 miles). The rose diagram describes the distribution of swell sizes and swell direction, while the graph at the bottom shows the same thing but without direction information. Five colours represent increasing wave sizes. Very small swells of less than 0.5m (1.5 feet) high are shown in blue. These happened only 90% of the time. Green and yellow show increasing swell sizes and red illustrates the highest swells, greater than >3m (>10ft). In both graphs, the area of any colour is proportional to how often that size swell was forecast. The diagram indicates that the dominant swell direction, shown by the largest spokes, was WSW, whereas the the dominant wind blows from the ENE. Because the wave model grid is away from the coast, sometimes a strong offshore wind blows largest waves away from Keaulanas 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 graph. Because wind determines whether or not waves are good for surfing at Keaulanas, you can view an alternative image that shows only the swells that were expected to coincide with glassy or offshore wind conditions. Over an average July, swells large enough to cause clean enough to surf waves at Keaulanas run for about 10% of the time.

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