Pokai Bay Surf Stats

The graph illustrates the combination of swells directed at Pokai Bay through a typical September, based on 3360 NWW3 model predictions since 2006 (values every 3 hours). The wave model does not forecast wind and surf right at the shore so we have chosen the most applicable grid node based on what we know about Pokai Bay. In the case of Pokai Bay, the best grid node is 32 km away (20 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 illustrate increasing wave sizes. Blue shows the smallest swells, less that 0.5m (1.5 feet) high. These happened only 70% of the time. Green and yellow illustrate increasing swell sizes and red shows largest swells greater than >3m (>10ft). In either graph, the area of any colour is proportional to how often that size swell happens. The diagram indicates that the dominant swell direction, shown by the longest spokes, was NW, whereas the the most common wind blows from the ENE. Because the wave model grid is out to sea, sometimes a strong offshore wind blows largest waves away from Pokai Bay and offshore. We lump these in with the no surf category of the bar chart. To keep it simple we don't show these in the rose diagram. Because wind determines whether or not waves are good for surfing at Pokai Bay, you can select a similar diagram that shows only the swells that were forecast to coincide with glassy or offshore wind conditions. Over an average September, swells large enough to cause clean enough to surf waves at Pokai Bay run for about 30% of the time.

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