Ocean Beach Jetty Surf Stats

The figure shows the variation of swells directed at Ocean Beach Jetty over a normal April and is based upon 2880 NWW3 model predictions since 2007 (values every 3 hours). The wave model does not forecast wind and surf right at the coastline so we have chosen the most applicable grid node based on what we know about Ocean Beach Jetty. In this particular case the best grid node is 35 km away (22 miles). The rose diagram shows the distribution of swell directions and swell sizes, 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 63% of the time. Green and yellow represent increasing swell sizes and red shows the biggest 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 most common swell direction, shown by the largest spokes, was WSW, whereas the the prevailing wind blows from the W. Because the wave model grid is offshore, sometimes a strong offshore wind blows largest waves away from Ocean Beach Jetty and away from the coast. 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 plot. Because wind determines whether or not waves are surfable at Ocean Beach Jetty, you can view an alternative image that shows only the swells that were expected to coincide with glassy or offshore wind conditions. During a typical April, swells large enough to cause good for surfing waves at Ocean Beach Jetty run for about 37% of the time.

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