North Jetty Surf Stats

This chart illustrates the variation of swells directed at North Jetty through a typical April and is based upon 2880 NWW3 model predictions since 2007 (values every 3 hours). The wave model does not forecast surf and wind right at the coastline so we have chosen the best grid node based on what we know about North Jetty. In the case of North Jetty, the best grid node is 33 km away (21 miles). The rose diagram illustrates 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 70% of the time. Green and yellow represent increasing swell sizes and red shows the largest swells, greater than >3m (>10ft). In both graphs, the area of any colour is proportional to how commonly that size swell happens. The diagram implies that the dominant swell direction, shown by the biggest spokes, was ENE, whereas the the most common wind blows from the S. Because the wave model grid is out to sea, sometimes a strong offshore wind blows largest waves away from North Jetty and offshore. We combine these 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 North Jetty, 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 April, swells large enough to cause clean enough to surf waves at North Jetty run for about 30% of the time.

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