Tuamotu Island Swell Statistics, Summer: All Swell – Any Wind
The figure shows the combination of swells directed at Tuamotu Island through an average southern hemisphere summer and is based upon 6365 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 Tuamotu Island. In this particular case the best grid node is 33 km away (21 miles).
The rose diagram describes the distribution of swell directions and swell sizes, 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 happened only 4% of the time. Green and yellow illustrate increasing swell sizes and red shows biggest swells greater than >3m (>10ft). In each graph, the area of any colour is proportional to how frequently that size swell occurs.
The diagram suggests that the prevailing swell direction, shown by the biggest spokes, was SE, whereas the the prevailing wind blows from the NNE. Because the wave model grid is offshore, sometimes a strong offshore wind blows largest waves away from Tuamotu Island and away from the coast. We group these with the no surf category of the bar chart. To avoid confusion we don't show these in the rose diagram. Because wind determines whether or not waves are clean enough to surf at Tuamotu Island, you can select a similar diagram that shows only the swells that were forecast to coincide with glassy or offshore wind conditions. In a typical southern hemisphere summer, swells large enough to cause surfable waves at Tuamotu Island run for about 96% 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.