Avalon-North Swell Statistics, Summer: All Swell – Any Wind
This image describes the variation of swells directed at Avalon-North through a typical southern hemisphere summer. It is based on 6931 NWW3 model predictions since 2006 (values every 3 hours). The wave model does not forecast wind or surf right at the coastline so we have chosen the best grid node based on what we know about Avalon-North. In this particular case the best grid node is 21 km away (13 miles).
The rose diagram illustrates the distribution of swell sizes and directions, while the graph at the bottom shows the same thing without direction information. Five colours illustrate increasing wave sizes. Blue shows the smallest swells, less that 0.5m (1.5 feet) high. These occurred only 38% of the time. Green and yellow represent 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 often that size swell was forecast.
The diagram indicates that the most common swell direction, shown by the longest spokes, was E (which was the same as the dominant wind direction). Because the wave model grid is away from the coast, sometimes a strong offshore wind blows largest waves away from Avalon-North and out to sea. We combine 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 clean enough to surf at Avalon-North, you can load a different image that shows only the swells that were forecast to coincide with glassy or offshore wind conditions. Over an average southern hemisphere summer, swells large enough to cause surfable waves at Avalon-North run for about 38% 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.