Kugenuma Rivermouth Surf Stats

This picture illustrates the range of swells directed at Kugenuma Rivermouth over a normal August. It is based on 3582 NWW3 model predictions since 2006 (values every 3 hours). The wave model does not forecast wind or surf right at the shore so we have chosen the optimum grid node based on what we know about Kugenuma Rivermouth, and at Kugenuma Rivermouth the best grid node is 35 km away (22 miles). The rose diagram illustrates 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 were forecast only 56% of the time. Green and yellow illustrate increasing swell sizes and red represents the largest swells, greater than >3m (>10ft). In both graphs, the area of any colour is proportional to how frequently that size swell was forecast. The diagram suggests that the most common swell direction, shown by the biggest spokes, was S, whereas the the most common wind blows from the SSE. Because the wave model grid is away from the coast, sometimes a strong offshore wind blows largest waves away from Kugenuma Rivermouth and out to sea. We combine these with the no surf category of the bar chart. To avoid confusion we don't show these in the rose plot. Because wind determines whether or not waves are clean enough to surf at Kugenuma Rivermouth, you can view an alternative image that shows only the swells that were predicted to coincide with glassy or offshore wind conditions. During a typical August, swells large enough to cause surfable waves at Kugenuma Rivermouth run for about 44% of the time.

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