Katwijk aan Zee Surf Stats

This chart shows the range of swells directed at Katwijk aan Zee through a typical September, based on 3347 NWW3 model predictions since 2006 (values every 3 hours). The wave model does not forecast wind and surf right at the coastline so we have chosen the best 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 but without direction information. Five colours represent increasing wave sizes. Very small swells of less than 0.5m (1.5 feet) high are shown in blue. These were forecast 56% of the time. Green and yellow illustrate increasing swell sizes and biggest swells greater than >3m (>10ft) are shown in red. In both graphs, 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 longest spokes, was NW, whereas the the prevailing wind blows from the WSW. Because the wave model grid is away from the coast, sometimes a strong offshore wind blows largest waves away from Katwijk aan Zee 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 Katwijk aan Zee, you can load a different image that shows only the swells that were expected to coincide with glassy or offshore wind conditions. Over an average September, swells large enough to cause surfable waves at Katwijk aan Zee run for about 44% of the time.

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