Anse Couleuvre Swell Statistics, December: All Swell – Any Wind
The graph describes the variation of swells directed at Anse Couleuvre over a normal December and is based upon 2457 NWW3 model predictions since 2006 (values every 3 hours). The wave model does not forecast surf and wind right at the coast so we have chosen the optimum grid node based on what we know about Anse Couleuvre. In the case of Anse Couleuvre, the best grid node is 28 km away (17 miles).
The rose diagram shows the distribution of swell sizes and swell direction, while the graph at the bottom shows the same thing without direction information. Five colours illustrate increasing wave sizes. Blue shows the smallest swells, less that 0.5m (1.5 feet) high. These were forecast only 57% of the time. Green and yellow represent increasing swell sizes and red represents highest swells greater than >3m (>10ft). In either graph, the area of any colour is proportional to how often that size swell was forecast.
The diagram indicates that the dominant swell direction, shown by the largest spokes, was NNE, whereas the the dominant wind blows from the ENE. Because the wave model grid is offshore, sometimes a strong offshore wind blows largest waves away from Anse Couleuvre and away from the coast. We group these 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 good for surfing at Anse Couleuvre, you can load a different image that shows only the swells that were expected to coincide with glassy or offshore wind conditions. During a typical December, swells large enough to cause clean enough to surf waves at Anse Couleuvre run for about 41% 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.