Crescent Swell Statistics, November: All Swell – Any Wind
The figure illustrates the combination of swells directed at Crescent through an average November, based on 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 Crescent. In this particular case the best grid node is 103 km away (64 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 show increasing wave sizes. The smallest swells, less than 0.5m (1.5 feet), high are coloured blue. These were forecast only 23% of the time. Green and yellow represent increasing swell sizes and red illustrates the largest swells, greater than >3m (>10ft). In both graphs, the area of any colour is proportional to how often that size swell occurs.
The diagram indicates that the dominant swell direction, shown by the biggest 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 Crescent 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 plot. Because wind determines whether or not waves are clean enough to surf at Crescent, 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 Crescent run for about 57% 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.