Green Island Surf Stats

The rose diagram shows the range of swells directed at Green Island through a typical July, based on 3472 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 most applicable grid node based on what we know about Green Island, and at Green Island the best grid node is 25 km away (16 miles). The rose diagram describes the distribution of swell sizes and swell direction, while the graph at the bottom shows the same thing without direction information. Five colours illustrate increasing wave sizes. Blue shows the smallest swells, less that 0.5m (1.5 feet) high. These happened only 29% of the time. Green and yellow show increasing swell sizes and red illustrates biggest swells greater than >3m (>10ft). In either graph, the area of any colour is proportional to how often that size swell was forecast. The diagram indicates that the most common swell direction, shown by the longest spokes, was SSE, whereas the the prevailing wind blows from the W. Because the wave model grid is out to sea, sometimes a strong offshore wind blows largest waves away from Green Island and offshore. We group these with the no surf category of the bar chart. To simplify things we don't show these in the rose plot. Because wind determines whether or not waves are surfable at Green Island, you can load a different image that shows only the swells that were predicted to coincide with glassy or offshore wind conditions. Over an average July, swells large enough to cause good for surfing waves at Green Island run for about 71% of the time.

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