Jack beach Surf Stats

This chart illustrates the variation of swells directed at Jack beach through an average May. It is based on 3440 NWW3 model predictions since 2007 (values every 3 hours). The wave model does not forecast wind and surf right at the shore so we have chosen the best grid node based on what we know about Jack beach. In the case of Jack beach, the best grid node is 12 km away (7 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 0.6% of the time. Green and yellow show increasing swell sizes and red represents the largest swells, greater than >3m (>10ft). In each graph, the area of any colour is proportional to how commonly that size swell was forecast. The diagram implies that the prevailing swell direction, shown by the largest spokes, was NW, whereas the the most common wind blows from the NNW. Because the wave model grid is out to sea, sometimes a strong offshore wind blows largest waves away from Jack beach 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 surfable at Jack beach, 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 May, swells large enough to cause good for surfing waves at Jack beach run for about 99% of the time.

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