Audierne Swell Statistics, Autumn: All Swell – Any Wind
This picture illustrates the combination of swells directed at Audierne over a normal northern hemisphere autumn. It is based on 7252 NWW3 model predictions since 2006 (values every 3 hours). The wave model does not forecast wind or surf right at the coast so we have chosen the optimum grid node based on what we know about Audierne. In the case of Audierne, the best grid node is 4 km away (2 miles).
The rose diagram shows the distribution of swell sizes and directions, while the graph at the bottom shows the same thing but lacks 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 were forecast only 20% of the time. Green and yellow show increasing swell sizes and largest swells greater than >3m (>10ft) are shown in red. In both graphs, 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 WSW (which was the same as the most common wind direction). Because the wave model grid is offshore, sometimes a strong offshore wind blows largest waves away from Audierne and away from the coast. We group these with the no surf category of the bar chart. To avoid confusion we don't show these in the rose diagram. Because wind determines whether or not waves are clean enough to surf at Audierne, you can load a different image that shows only the swells that were predicted to coincide with glassy or offshore wind conditions. During a typical northern hemisphere autumn, swells large enough to cause surfable waves at Audierne run for about 61% 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.