Hilo Breakwall Surf Stats

This picture shows the range of swells directed at Hilo Breakwall through a typical May, based on 3440 NWW3 model predictions since 2007 (values every 3 hours). The wave model does not forecast surf and wind right at the coast so we have chosen the most applicable grid node based on what we know about Hilo Breakwall. In this particular case the best grid node is 30 km away (19 miles). The rose diagram illustrates the distribution of swell sizes and swell direction, 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 68% of the time. Green and yellow illustrate increasing swell sizes and red illustrates biggest swells greater than >3m (>10ft). In both graphs, the area of any colour is proportional to how frequently that size swell happens. The diagram suggests that the prevailing swell direction, shown by the longest spokes, was N, whereas the the prevailing wind blows from the ESE. Because the wave model grid is away from the coast, sometimes a strong offshore wind blows largest waves away from Hilo Breakwall 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 diagram. Because wind determines whether or not waves are surfable at Hilo Breakwall, 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 May, swells large enough to cause good for surfing waves at Hilo Breakwall run for about 32% of the time.

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