Yoff Island Surf Stats

The figure describes the range of swells directed at Yoff Island through an average April, based on 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 best grid node based on what we know about Yoff Island. In this particular case the best grid node is 25 km away (16 miles). The rose diagram describes the distribution of swell sizes and swell direction, 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 occurred only 13% of the time. Green and yellow represent increasing swell sizes and red illustrates highest swells greater than >3m (>10ft). In both graphs, the area of any colour is proportional to how commonly that size swell happens. The diagram implies that the prevailing swell direction, shown by the longest spokes, was NW, whereas the the dominant wind blows from the NNW. Because the wave model grid is away from the coast, sometimes a strong offshore wind blows largest waves away from Yoff Island and out to sea. We lump these in with the no surf category of the bar chart. To simplify things we don't show these in the rose graph. Because wind determines whether or not waves are clean enough to surf at Yoff Island, you can load a different image that shows only the swells that were expected to coincide with glassy or offshore wind conditions. In a typical April, swells large enough to cause surfable waves at Yoff Island run for about 87% of the time.

read more