Happy Jacks Surf Stats

This picture shows the range of swells directed at Happy Jacks through a typical July. It is based on 3720 NWW3 model predictions since 2006 (values every 3 hours). The wave model does not forecast surf and wind right at the shore so we have chosen the best grid node based on what we know about Happy Jacks, and at Happy Jacks the best grid node is 9 km away (6 miles). The rose diagram shows the distribution of swell sizes and swell direction, while the graph at the bottom shows the same thing but lacks direction information. Five colours show increasing wave sizes. The smallest swells, less than 0.5m (1.5 feet), high are coloured blue. These were forecast only 71% of the time. Green and yellow represent increasing swell sizes and biggest swells greater than >3m (>10ft) are shown in red. In either 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 ENE, whereas the the prevailing wind blows from the WNW. Because the wave model grid is offshore, sometimes a strong offshore wind blows largest waves away from Happy Jacks and away from the coast. We lump these in 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 clean enough to surf at Happy Jacks, you can select a similar diagram 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 surfable waves at Happy Jacks run for about 29% of the time.

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