This image shows only the swells directed at Barre de Balizas that coincided with light winds or offshore conditions through a typical southern hemisphere winter and is based upon 5066 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 represents the biggest swells, greater than >3m (>10ft). In both graphs, the area of any colour is proportional to how frequently that size swell occurs.
The diagram suggests that the dominant swell direction, shown by the largest spokes, was SE, whereas the the prevailing wind blows from the W. 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 32% of the time, equivalent to 29 days. Open water swells exceeding >3m (>10ft) only happen 0.6% of the time in a typical southern hemisphere winter, equivalent to just one day but 4% of the time we expect swell in the range 2-3m (6.5-10ft) 4%, equivalent to (4 days). Taking into account the proportion of these swells that coincided with predicted offshore winds, and given the fact that Barre de Balizas is exposed to open water swells, we think that that clean surf can be found at Barre de Balizas about 32% of the time and that surf is messed up by onshore wind 42% of the time. This is means that we expect 67 days with waves in a typical southern hemisphere winter, of which 29 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.