Bay of Skaill Surf Stats

The rose diagram illustrates the range of swells directed at Bay of Skaill through a typical November, based on 3347 NWW3 model predictions since 2006 (values every 3 hours). The wave model does not forecast wind and surf right at the coast so we have chosen the best grid node based on what we know about Bay of Skaill. In this particular case the best grid node is 11 km away (7 miles). The rose diagram shows the distribution of swell sizes and swell direction, 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 18% of the time. Green and yellow show increasing swell sizes and largest swells greater than >3m (>10ft) are shown in red. In either graph, the area of any colour is proportional to how often that size swell happens. The diagram indicates that the most common swell direction, shown by the largest spokes, was WNW, whereas the the most common wind blows from the SW. Because the wave model grid is offshore, sometimes a strong offshore wind blows largest waves away from Bay of Skaill and away from the coast. 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 plot. Because wind determines whether or not waves are surfable at Bay of Skaill, you can load a different image that shows only the swells that were predicted to coincide with glassy or offshore wind conditions. Over an average November, swells large enough to cause good for surfing waves at Bay of Skaill run for about 82% of the time.

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