Bunkers Swell Statistics, November: All Swell – Any Wind
This picture shows the range of swells directed at Bunkers through an average November. It is based on 2387 NWW3 model predictions since 2006 (values every 3 hours). The wave model does not forecast wind and surf right at the shore so we have chosen the most applicable grid node based on what we know about Bunkers. In this particular case the best grid node is 34 km away (21 miles).
The rose diagram describes the distribution of swell sizes and swell direction, 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 occurred only 30% of the time. Green and yellow illustrate increasing swell sizes and red illustrates biggest swells greater than >3m (>10ft). In each graph, the area of any colour is proportional to how often that size swell happens.
The diagram indicates that the most common swell direction, shown by the biggest spokes, was W, whereas the the prevailing wind blows from the SW. Because the wave model grid is offshore, sometimes a strong offshore wind blows largest waves away from Bunkers and away from the coast. We combine these with the no surf category of the bar chart. To keep it simple we don't show these in the rose diagram. Because wind determines whether or not waves are clean enough to surf at Bunkers, you can load a different image that shows only the swells that were expected to coincide with glassy or offshore wind conditions. In a typical November, swells large enough to cause surfable waves at Bunkers run for about 70% 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.