Port Robinson Surf Stats

This picture describes the range of swells directed at Port Robinson over a normal 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 most applicable grid node based on what we know about Port Robinson, and at Port Robinson the best grid node is 20 km away (12 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 show increasing wave sizes. The smallest swells, less than 0.5m (1.5 feet), high are coloured blue. These occurred only 22% of the time. Green and yellow illustrate increasing swell sizes and highest swells greater than >3m (>10ft) are shown in red. In each graph, the area of any colour is proportional to how commonly that size swell occurs. The diagram implies that the most common swell direction, shown by the longest spokes, was SE, whereas the the dominant wind blows from the WNW. Because the wave model grid is out to sea, sometimes a strong offshore wind blows largest waves away from Port Robinson and offshore. 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 Port Robinson, you can select a similar diagram that shows only the swells that were predicted to coincide with glassy or offshore wind conditions. During a typical July, swells large enough to cause clean enough to surf waves at Port Robinson run for about 78% of the time.

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