The Dump Swell Statistics, November: All Swell – Any Wind
This picture illustrates the range of swells directed at The Dump through an average November and is based upon 2147 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 most applicable grid node based on what we know about The Dump. In this particular case the best grid node is 28 km away (17 miles).
The rose diagram describes the distribution of swell sizes and swell direction, 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 happened only 6% 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 prevailing swell direction, shown by the largest spokes, was W, whereas the the most common wind blows from the SSE. Because the wave model grid is offshore, sometimes a strong offshore wind blows largest waves away from The Dump 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 surfable at The Dump, you can load a different image that shows only the swells that were expected to coincide with glassy or offshore wind conditions. In a typical November, swells large enough to cause good for surfing waves at The Dump run for about 94% 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.