Grim Ness Surf Stats

The rose diagram shows the combination of swells directed at Grim Ness over a normal April, based on 3360 NWW3 model predictions since 2007 (values every 3 hours). The wave model does not forecast wind or surf right at the shore so we have chosen the best grid node based on what we know about Grim Ness. In this particular case the best grid node is 29 km away (18 miles). The rose diagram describes the distribution of swell sizes and directions, while the graph at the bottom shows the same thing without direction information. Five colours illustrate increasing wave sizes. Blue shows the smallest swells, less that 0.5m (1.5 feet) high. These happened only 65% of the time. Green and yellow represent increasing swell sizes and biggest swells greater than >3m (>10ft) are shown in red. In each graph, the area of any colour is proportional to how frequently that size swell occurs. The diagram suggests that the dominant swell direction, shown by the longest spokes, was NE, whereas the the prevailing wind blows from the SSW. Because the wave model grid is offshore, sometimes a strong offshore wind blows largest waves away from Grim Ness and away from the coast. We lump these in with the no surf category of the bar chart. To simplify things we don't show these in the rose plot. Because wind determines whether or not waves are clean enough to surf at Grim Ness, you can load a different image that shows only the swells that were expected to coincide with glassy or offshore wind conditions. During a typical April, swells large enough to cause surfable waves at Grim Ness run for about 35% of the time.

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