Anse des Cayes Swell Statistics, October: All Swell – Any Wind
This picture illustrates the variation of swells directed at Anse des Cayes through an average October, based on 2480 NWW3 model predictions since 2006 (values every 3 hours). The wave model does not forecast wind or surf right at the shore so we have chosen the best grid node based on what we know about Anse des Cayes, and at Anse des Cayes the best grid node is 19 km away (12 miles).
The rose diagram illustrates the distribution of swell sizes and swell direction, while the graph at the bottom shows the same thing but without direction information. Five colours illustrate increasing wave sizes. Blue shows the smallest swells, less that 0.5m (1.5 feet) high. These occurred only 37% of the time. Green and yellow illustrate increasing swell sizes and red represents largest swells greater than >3m (>10ft). In each 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 biggest spokes, was NE, whereas the the most common wind blows from the ESE. Because the wave model grid is offshore, sometimes a strong offshore wind blows largest waves away from Anse des Cayes 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 graph. Because wind determines whether or not waves are clean enough to surf at Anse des Cayes, you can select a similar diagram that shows only the swells that were expected to coincide with glassy or offshore wind conditions. In a typical October, swells large enough to cause surfable waves at Anse des Cayes run for about 16% 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.