South Bird Rock Surf Stats

The figure describes the combination of swells directed at South Bird Rock through a typical April, based on 3360 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 best grid node based on what we know about South Bird Rock. In the case of South Bird Rock, the best grid node is 29 km away (18 miles). The rose diagram shows the distribution of swell sizes and directions, while the graph at the bottom shows the same thing but without direction information. Five colours illustrate increasing wave sizes. Blue shows the smallest swells, less that 0.5m (1.5 feet) high. These were forecast only 2% of the time. Green and yellow represent increasing swell sizes and red illustrates the highest swells, greater than >3m (>10ft). In each graph, the area of any colour is proportional to how frequently that size swell was forecast. The diagram suggests that the most common swell direction, shown by the biggest spokes, was SW, whereas the the dominant wind blows from the WSW. Because the wave model grid is offshore, sometimes a strong offshore wind blows largest waves away from South Bird Rock 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 diagram. Because wind determines whether or not waves are clean enough to surf at South Bird Rock, you can select a similar diagram 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 South Bird Rock run for about 98% of the time.

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