This image shows only the swells directed at Mussulo that coincided with light winds or offshore conditions through a typical June. It is based on 1594 predictions, one every 3 hours. The direction of the spokes show where quality surf generating swell comes from. Five colours illustrate increasing wave sizes. Blue shows the smallest swells, less that 0.5m (1.5 feet) high. Green and yellow show increasing swell sizes and biggest swells greater than >3m (>10ft) are shown in red. In either graph, the area of any colour is proportional to how commonly that size swell occurs.
The diagram implies that the dominant swell direction, shown by the longest spokes, was SW, whereas the the prevailing wind blows from the S. 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 14% of the time, equivalent to 4 days. Open sea swells exceeding >3m (>10ft) are unlikely to happen in a normal June 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 proportion of these swells that coincided with expected offshore winds, and given the fact that Mussulo is slightly protected from open water swells, we estimate that clean surf can be found at Mussulo about 14% of the time and that surf is messed up by onshore wind 58% of the time. This is means that we expect 22 days with waves in a typical June, of which 4 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.