Lorient Swell Statistics, March: All Swell – Any Wind
This image illustrates the variation of swells directed at Lorient over a normal March. It is based on 1724 NWW3 model predictions since 2007 (values every 3 hours). The wave model does not forecast surf and wind right at the coast so we have chosen the most applicable grid node based on what we know about Lorient. In this particular case the best grid node is 21 km away (13 miles).
The rose diagram illustrates the distribution of swell sizes and swell direction, 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 happened only 4% of the time. Green and yellow show increasing swell sizes and largest swells greater than >3m (>10ft) are shown in red. In each graph, the area of any colour is proportional to how often that size swell happens.
The diagram indicates that the most common swell direction, shown by the biggest spokes, was NE, whereas the the most common wind blows from the E. Because the wave model grid is away from the coast, sometimes a strong offshore wind blows largest waves away from Lorient and out to sea. 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 Lorient, 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 surfable waves at Lorient run for about 96% 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.