Bertha's Beach Surf Stats

The figure describes the variation of swells directed at Bertha's Beach through an average April. It is 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 optimum grid node based on what we know about Bertha's Beach. In this particular case the best grid node is 29 km away (18 miles). The rose diagram shows the distribution of swell directions and swell sizes, while the graph at the bottom shows the same thing but lacks direction information. Five colours show increasing wave sizes. The smallest swells, less than 0.5m (1.5 feet), high are coloured blue. These happened only 17% of the time. Green and yellow show increasing swell sizes and red represents highest swells greater than >3m (>10ft). In either graph, the area of any colour is proportional to how commonly that size swell was forecast. The diagram implies that the prevailing swell direction, shown by the largest spokes, was SSE, whereas the the dominant wind blows from the W. Because the wave model grid is offshore, sometimes a strong offshore wind blows largest waves away from Bertha's Beach and away from the coast. We combine these with the no surf category of the bar chart. To simplify things we don't show these in the rose diagram. Because wind determines whether or not waves are clean enough to surf at Bertha's Beach, you can load a different image that shows only the swells that were forecast to coincide with glassy or offshore wind conditions. In a typical April, swells large enough to cause surfable waves at Bertha's Beach run for about 83% of the time.

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