San Gallan Surf Stats

The rose diagram describes the variation of swells directed at San Gallan through an average August. It is based on 3472 NWW3 model predictions since 2006 (values every 3 hours). The wave model does not forecast wind or surf right at the coastline so we have chosen the optimum grid node based on what we know about San Gallan. In this particular case the best grid node is 20 km away (12 miles). The rose diagram shows the distribution of swell sizes and directions, while the graph at the bottom shows the same thing but lacks direction information. Five colours illustrate increasing wave sizes. Blue shows the smallest swells, less that 0.5m (1.5 feet) high. These happened only 54% of the time. Green and yellow represent increasing swell sizes and red represents the highest swells, greater than >3m (>10ft). In each graph, the area of any colour is proportional to how often that size swell occurs. The diagram indicates that the prevailing swell direction, shown by the longest spokes, was SSW, whereas the the dominant wind blows from the S. Because the wave model grid is out to sea, sometimes a strong offshore wind blows largest waves away from San Gallan and offshore. 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 graph. Because wind determines whether or not waves are surfable at San Gallan, you can view an alternative image that shows only the swells that were expected to coincide with glassy or offshore wind conditions. In a typical August, swells large enough to cause good for surfing waves at San Gallan run for about 46% of the time.

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