The figure describes the range of swells directed at Quarantine through an average June, based on 1594 NWW3 model predictions since 2006 (values every 3 hours). The wave model does not forecast wind or surf right at the coast so we have chosen the optimum grid node based on what we know about Quarantine. In the case of Quarantine, the best grid node is 25 km away (16 miles).
The rose diagram illustrates the distribution of swell directions and swell sizes, while the graph at the bottom shows the same thing but without direction information. Five colours represent increasing wave sizes. Very small swells of less than 0.5m (1.5 feet) high are shown in blue. These happened only 12% 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 occurs.
The diagram suggests that the dominant swell direction, shown by the longest spokes, was SW, whereas the the dominant 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 Quarantine and out to sea. We group these 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 good for surfing at Quarantine, you can load a different image that shows only the swells that were predicted to coincide with glassy or offshore wind conditions. In a typical June, swells large enough to cause clean enough to surf waves at Quarantine run for about 88% 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.