West Wittering Swell Statistics, December: All Swell – Any Wind
This picture illustrates the range of swells directed at West Wittering through an average December and is based upon 1465 NWW3 model predictions since 2008 (values every 3 hours). The wave model does not forecast wind or surf right at the shore so we have chosen the most applicable grid node based on what we know about West Wittering, and at West Wittering the best grid node is 31 km away (19 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 show increasing wave sizes. The smallest swells, less than 0.5m (1.5 feet), high are coloured blue. These happened only 44% of the time. Green and yellow show increasing swell sizes and red illustrates largest swells greater than >3m (>10ft). In either graph, the area of any colour is proportional to how often that size swell happens.
The diagram indicates that the dominant swell direction, shown by the longest spokes, was SW, whereas the the most common wind blows from the WNW. Because the wave model grid is away from the coast, sometimes a strong offshore wind blows largest waves away from West Wittering and out to sea. We lump these in with the no surf category of the bar chart. To keep it simple we don't show these in the rose graph. Because wind determines whether or not waves are clean enough to surf at West Wittering, you can view an alternative image that shows only the swells that were predicted to coincide with glassy or offshore wind conditions. In a typical December, swells large enough to cause surfable waves at West Wittering run for about 17% 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.