Bolina Surf Stats

The graph describes the variation of swells directed at Bolina through a typical April and is based upon 3360 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 optimum grid node based on what we know about Bolina. In the case of Bolina, the best grid node is 24 km away (15 miles). The rose diagram describes 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 were forecast only 83% of the time. Green and yellow represent increasing swell sizes and red shows the highest swells, greater than >3m (>10ft). In each graph, the area of any colour is proportional to how commonly that size swell happens. The diagram implies that the most common swell direction, shown by the biggest spokes, was WSW, whereas the the dominant wind blows from the NW. Because the wave model grid is offshore, sometimes a strong offshore wind blows largest waves away from Bolina and away from the coast. We lump these in with the no surf category of the bar chart. To avoid confusion we don't show these in the rose plot. Because wind determines whether or not waves are surfable at Bolina, you can load a different 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 good for surfing waves at Bolina run for about 13% of the time.

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