This image shows only the swells directed at Pontal that coincided with light winds or offshore conditions through a typical July. It is based on 1736 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 illustrate increasing swell sizes and red illustrates the highest swells, greater than >3m (>10ft). In both graphs, the area of any colour is proportional to how often that size swell was forecast.
The diagram indicates that the dominant swell direction, shown by the longest spokes, was ESE, whereas the the dominant wind blows from the SE. 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 24% of the time, equivalent to 7 days. Open sea swells exceeding >3m (>10ft) are unlikely to occur in a normal July but 12% of the time you can expect swell in the range 1.3-2m (4-6.5ft) 12%, equivalent to (4 days). Taking into account the ratio of these swells that coincided with expected offshore winds, and given the fact that Pontal is exposed to open water swells, we think that that clean surf can be found at Pontal about 24% of the time and that surf is messed up by onshore wind 75% of the time. This is means that we expect 31 days with waves in a typical July, of which 7 days should be clean enough to surf.
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.