Statistiques de Houle pour Anse Trabaud, Mars: Toutes Houles – Tous Vents
The graph describes the variation of swells directed at Anse Trabaud over a normal March. It is based on 2220 NWW3 model predictions since 2007 (values every 3 hours). The wave model does not forecast wind or surf right at the coastline so we have chosen the most applicable grid node based on what we know about Anse Trabaud. In the case of Anse Trabaud, the best grid node is 19 km away (12 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 37% of the time. Green and yellow illustrate increasing swell sizes and red represents the highest swells, greater than >3m (>10ft). In either graph, 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 E (which was the same as the dominant wind direction). Because the wave model grid is out to sea, sometimes a strong offshore wind blows largest waves away from Anse Trabaud and offshore. We group these 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 good for surfing at Anse Trabaud, you can select a similar diagram that shows only the swells that were forecast to coincide with glassy or offshore wind conditions. During a typical March, swells large enough to cause clean enough to surf waves at Anse Trabaud run for about 37% 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.