This image shows only the swells directed at Havaizinho that coincided with light winds or offshore conditions through a typical southern hemisphere autumn. It is based on 5140 predictions, one every 3 hours. The direction of the spokes show where quality surf generating swell comes from. Five colours show increasing wave sizes. The smallest swells, less than 0.5m (1.5 feet), high are coloured blue. Green and yellow represent increasing swell sizes and red illustrates highest swells greater than >3m (>10ft). In both graphs, the area of any colour is proportional to how often that size swell happens.
The diagram indicates that the dominant swell direction, shown by the longest spokes, was ESE (which was the same as the dominant wind direction). The chart at the bottom shows the same thing but without direction information. For example, swells larger than 1.5 feet (0.5m) coincided with good wind conditions 34% of the time, equivalent to 31 days. Open sea swells exceeding >3m (>10ft) are unlikely to arise in a normal southern hemisphere autumn but 8% of the time you can expect swell in the range 1.3-2m (4-6.5ft) 8%, equivalent to (7 days). Taking into account the proportion of these swells that coincided with forecast offshore winds, and given the fact that Havaizinho is exposed to open water swells, we think that that clean surf can be found at Havaizinho about 34% of the time and that surf is messed up by onshore wind 66% of the time. This is means that we expect 91 days with waves in a typical southern hemisphere autumn, of which 31 days should be surfable.
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.