Afife Swell Statistics, Autumn: Surf with Light or Offshore Winds
This image shows only the swells directed at Afife that coincided with light winds or offshore conditions through a typical northern hemisphere autumn. It is based on 7252 predictions, one every 3 hours. The direction of the spokes show where quality surf generating swell comes from. Five colours represent increasing wave sizes. Very small swells of less than 0.5m (1.5 feet) high are shown in blue. Green and yellow show increasing swell sizes and highest swells greater than >3m (>10ft) are shown in red. In each graph, the area of any colour is proportional to how frequently that size swell occurs.
The diagram suggests that the most common swell direction, shown by the biggest spokes, was WNW, whereas the the dominant wind blows from the N. 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 water swells exceeding >3m (>10ft) only happen 1.5% of the time in a typical northern hemisphere autumn, equivalent to just one day but 8% of the time we expect swell in the range 2-3m (6.5-10ft) 8%, equivalent to (7 days). Taking into account the ratio of these swells that coincided with expected offshore winds, and given the fact that Afife is exposed to open water swells, we estimate that clean surf can be found at Afife about 34% of the time and that surf is spoilt by onshore wind 60% of the time. This is means that we expect 86 days with waves in a typical northern 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.