Aberavon Swell Statistics, March: All Swell – Any Wind
This image describes the range of swells directed at Aberavon over a normal March and is based upon 2220 NWW3 model predictions since 2007 (values every 3 hours). The wave model does not forecast wind or surf right at the shore so we have chosen the optimum grid node based on what we know about Aberavon, and at Aberavon the best grid node is 16 km away (10 miles).
The rose diagram shows the distribution of swell sizes and directions, while the graph at the bottom shows the same thing without direction information. Five colours show increasing wave sizes. The smallest swells, less than 0.5m (1.5 feet), high are coloured blue. These occurred 27% of the time. Green and yellow illustrate increasing swell sizes and highest 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 dominant swell direction, shown by the largest spokes, was WSW, whereas the the dominant wind blows from the W. Because the wave model grid is away from the coast, sometimes a strong offshore wind blows largest waves away from Aberavon and out to sea. 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 surfable at Aberavon, you can view an alternative image that shows only the swells that were expected to coincide with glassy or offshore wind conditions. During a typical March, swells large enough to cause good for surfing waves at Aberavon run for about 73% 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.