Kawaihae Breakwater Surf Stats

The rose diagram shows the combination of swells directed at Kawaihae Breakwater over a normal April, based on 3360 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 most applicable grid node based on what we know about Kawaihae Breakwater. In the case of Kawaihae Breakwater, the best grid node is 18 km away (11 miles). The rose diagram illustrates the distribution of swell sizes and directions, while the graph at the bottom shows the same thing but lacks 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 occurred only 53% of the time. Green and yellow show increasing swell sizes and biggest swells greater than >3m (>10ft) are shown in red. In both graphs, the area of any colour is proportional to how frequently that size swell was forecast. The diagram suggests that the dominant swell direction, shown by the biggest spokes, was WSW, whereas the the prevailing wind blows from the N. Because the wave model grid is away from the coast, sometimes a strong offshore wind blows largest waves away from Kawaihae Breakwater and out to sea. We combine 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 surfable at Kawaihae Breakwater, 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 April, swells large enough to cause good for surfing waves at Kawaihae Breakwater run for about 5% of the time.

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