Campbells Swell Statistics, November: All Swell – Any Wind
The figure describes the range of swells directed at Campbells through a typical November. It is based on 2147 NWW3 model predictions since 2006 (values every 3 hours). The wave model does not forecast surf and wind right at the coastline so we have chosen the most applicable grid node based on what we know about Campbells. In this particular case the best grid node is 36 km away (22 miles).
The rose diagram describes the distribution of swell sizes and directions, while the graph at the bottom shows the same thing but lacks direction information. Five colours illustrate increasing wave sizes. Blue shows the smallest swells, less that 0.5m (1.5 feet) high. These happened only 84% of the time. Green and yellow show increasing swell sizes and red illustrates highest swells greater than >3m (>10ft). In either graph, the area of any colour is proportional to how frequently that size swell was forecast.
The diagram suggests that the dominant swell direction, shown by the longest spokes, was SSW, whereas the the dominant wind blows from the ENE. Because the wave model grid is out to sea, sometimes a strong offshore wind blows largest waves away from Campbells and offshore. We group these with the no surf category of the bar chart. To keep it simple we don't show these in the rose plot. Because wind determines whether or not waves are clean enough to surf at Campbells, you can view an alternative image that shows only the swells that were predicted to coincide with glassy or offshore wind conditions. Over an average November, swells large enough to cause surfable waves at Campbells run for about 16% 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.