Ocean Beach Surf Stats

This chart describes the variation of swells directed at Ocean Beach 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 coast so we have chosen the best grid node based on what we know about Ocean Beach. In this particular case the best grid node is 26 km away (16 miles). The rose diagram describes the distribution of swell directions and swell sizes, 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 were forecast only 9% of the time. Green and yellow show increasing swell sizes and red shows the highest swells, greater than >3m (>10ft). In both graphs, the area of any colour is proportional to how often that size swell was forecast. The diagram indicates that the prevailing swell direction, shown by the biggest spokes, was W, whereas the the dominant wind blows from the WNW. Because the wave model grid is out to sea, sometimes a strong offshore wind blows largest waves away from Ocean Beach and offshore. We combine these with the no surf category of the bar chart. To avoid confusion we don't show these in the rose diagram. Because wind determines whether or not waves are clean enough to surf at Ocean Beach, you can view an alternative image that shows only the swells that were forecast to coincide with glassy or offshore wind conditions. Over an average April, swells large enough to cause surfable waves at Ocean Beach run for about 91% of the time.

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