Katwijk aan Zee Surf Stats

The rose diagram describes the combination of swells directed at Katwijk aan Zee through an average November, based on 3345 NWW3 model predictions since 2006 (values every 3 hours). The wave model does not forecast surf and wind right at the shore so we have chosen the most applicable grid node based on what we know about Katwijk aan Zee. In the case of Katwijk aan Zee, the best grid node is 31 km away (19 miles). The rose diagram illustrates the distribution of swell sizes and directions, 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 58% of the time. Green and yellow illustrate increasing swell sizes and red shows highest swells greater than >3m (>10ft). In both graphs, the area of any colour is proportional to how often that size swell happens. The diagram indicates that the prevailing swell direction, shown by the longest spokes, was NW, whereas the the dominant wind blows from the SW. Because the wave model grid is offshore, sometimes a strong offshore wind blows largest waves away from Katwijk aan Zee and away from the coast. We group these with the no surf category of the bar chart. To avoid confusion we don't show these in the rose graph. Because wind determines whether or not waves are good for surfing at Katwijk aan Zee, you can load a different image that shows only the swells that were predicted to coincide with glassy or offshore wind conditions. In a typical November, swells large enough to cause clean enough to surf waves at Katwijk aan Zee run for about 42% of the time.

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