Anse des Cayes Swell Statistics, Summer: All Swell – Any Wind
The rose diagram shows the range of swells directed at Anse des Cayes through a typical northern hemisphere summer. It is based on 7266 NWW3 model predictions since 2006 (values every 3 hours). The wave model does not forecast wind and surf right at the coast so we have chosen the best grid node based on what we know about Anse des Cayes. In the case of Anse des Cayes, the best grid node is 19 km away (12 miles).
The rose diagram describes the distribution of swell directions and swell sizes, 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 occurred only 67% of the time. Green and yellow represent increasing swell sizes and biggest swells greater than >3m (>10ft) are shown in red. In both graphs, the area of any colour is proportional to how commonly that size swell happens.
The diagram implies that the prevailing swell direction, shown by the biggest spokes, was ENE, whereas the the prevailing wind blows from the E. Because the wave model grid is out to sea, sometimes a strong offshore wind blows largest waves away from Anse des Cayes and offshore. We lump these in 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 good for surfing at Anse des Cayes, you can load a different image that shows only the swells that were expected to coincide with glassy or offshore wind conditions. Over an average northern hemisphere summer, swells large enough to cause clean enough to surf waves at Anse des Cayes run for about 11% 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.