The rose diagram describes the combination of swells directed at Akkorokamui through an average September and is based upon 1680 NWW3 model predictions since 2006 (values every 3 hours). The wave model does not forecast surf and wind right at the shore so we have chosen the best grid node based on what we know about Akkorokamui. In the case of Akkorokamui, the best grid node is 9 km away (6 miles).
The rose diagram illustrates the distribution of swell sizes and directions, while the graph at the bottom shows the same thing but 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 27% of the time. Green and yellow represent increasing swell sizes and red shows the highest swells, greater than >3m (>10ft). In each graph, the area of any colour is proportional to how commonly that size swell was forecast.
The diagram implies that the most common swell direction, shown by the largest spokes, was E, whereas the the dominant wind blows from the N. Because the wave model grid is offshore, sometimes a strong offshore wind blows largest waves away from Akkorokamui and away from the coast. We lump these in 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 Akkorokamui, you can view an alternative image that shows only the swells that were expected to coincide with glassy or offshore wind conditions. In a typical September, swells large enough to cause surfable waves at Akkorokamui run for about 73% 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.