The Dump Swell Statistics, November: All Swell – Any Wind
The figure illustrates the combination of swells directed at The Dump through an average November, based on 1907 NWW3 model predictions since 2006 (values every 3 hours). The wave model does not forecast wind and surf right at the shore so we have chosen the optimum grid node based on what we know about The Dump, and at The Dump the best grid node is 28 km away (17 miles).
The rose diagram describes the distribution of swell sizes and directions, while the graph at the bottom shows the same thing but lacks 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 happened only 7% of the time. Green and yellow illustrate increasing swell sizes and red shows largest swells greater than >3m (>10ft). In both graphs, the area of any colour is proportional to how frequently that size swell occurs.
The diagram suggests that the most common swell direction, shown by the longest spokes, was W, whereas the the most common wind blows from the SSE. Because the wave model grid is away from the coast, sometimes a strong offshore wind blows largest waves away from The Dump and out to sea. We group these with the no surf category of the bar chart. To avoid confusion we don't show these in the rose diagram. Because wind determines whether or not waves are clean enough to surf at The Dump, you can select a similar diagram that shows only the swells that were forecast to coincide with glassy or offshore wind conditions. In a typical November, swells large enough to cause surfable waves at The Dump run for about 93% of the time.
IMPORTANT: Beta version feature! Swell heights are open water values from NWW3. There is no attempt to model near-shore effects. Coastal wave heights will generally be less, especially if the break does not have unobstructed exposure to the open ocean.