Greenhill Surf Stats

This chart shows the variation of swells directed at Greenhill through an average November, based on 3347 NWW3 model predictions since 2006 (values every 3 hours). The wave model does not forecast wind or surf right at the coast so we have chosen the optimum grid node based on what we know about Greenhill. In the case of Greenhill, the best grid node is 41 km away (25 miles). The rose diagram describes the distribution of swell sizes and directions, while the graph at the bottom shows the same thing 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 occurred only 35% of the time. Green and yellow show increasing swell sizes and red represents biggest swells greater than >3m (>10ft). In either graph, the area of any colour is proportional to how commonly that size swell occurs. The diagram implies that the dominant swell direction, shown by the biggest spokes, was SSE, whereas the the prevailing wind blows from the WNW. Because the wave model grid is out to sea, sometimes a strong offshore wind blows largest waves away from Greenhill 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 diagram. Because wind determines whether or not waves are clean enough to surf at Greenhill, you can select a similar diagram that shows only the swells that were forecast to coincide with glassy or offshore wind conditions. In a typical November, swells large enough to cause surfable waves at Greenhill run for about 35% of the time.

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