Dewey Beach Surf Stats

The graph illustrates the range of swells directed at Dewey Beach over a normal July. It is based on 2976 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 Dewey Beach. In this particular case the best grid node is 23 km away (14 miles). The rose diagram describes 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 only 17% of the time. Green and yellow represent increasing swell sizes and red illustrates largest swells greater than >3m (>10ft). In either graph, the area of any colour is proportional to how often that size swell happens. The diagram indicates that the dominant swell direction, shown by the largest spokes, was SE, 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 Dewey Beach 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 Dewey Beach, you can load a different image that shows only the swells that were forecast to coincide with glassy or offshore wind conditions. During a typical July, swells large enough to cause surfable waves at Dewey Beach run for about 83% of the time.

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