Tarnos - La Digue Swell Statistics, May: All Swell – Any Wind
The graph illustrates the variation of swells directed at Tarnos - La Digue over a normal May. It is based on 2200 NWW3 model predictions since 2007 (values every 3 hours). The wave model does not forecast wind and surf right at the shore so we have chosen the best grid node based on what we know about Tarnos - La Digue, and at Tarnos - La Digue the best grid node is 39 km away (24 miles).
The rose diagram describes the distribution of swell sizes and directions, 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 were forecast only 9% of the time. Green and yellow show increasing swell sizes and red represents the largest swells, greater than >3m (>10ft). In either graph, the area of any colour is proportional to how frequently that size swell was forecast.
The diagram suggests that the dominant swell direction, shown by the biggest spokes, was WNW, whereas the the most common wind blows from the NW. Because the wave model grid is out to sea, sometimes a strong offshore wind blows largest waves away from Tarnos - La Digue and offshore. 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 surfable at Tarnos - La Digue, 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 May, swells large enough to cause good for surfing waves at Tarnos - La Digue run for about 91% 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.