Utua Mamao (Atafu) Surf Stats

The rose diagram illustrates the combination of swells directed at Utua Mamao (Atafu) over a normal August. It is based on 3472 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 best grid node based on what we know about Utua Mamao (Atafu), and at Utua Mamao (Atafu) the best grid node is 8 km away (5 miles). The rose diagram illustrates the distribution of swell sizes and directions, while the graph at the bottom shows the same thing 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 73% 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 happens. The diagram suggests that the most common swell direction, shown by the biggest spokes, was SSE, whereas the the most common wind blows from the E. Because the wave model grid is away from the coast, sometimes a strong offshore wind blows largest waves away from Utua Mamao (Atafu) and out to sea. We lump these in 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 Utua Mamao (Atafu), you can select a similar diagram that shows only the swells that were expected to coincide with glassy or offshore wind conditions. During a typical August, swells large enough to cause surfable waves at Utua Mamao (Atafu) run for about 27% of the time.

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