Afife Swell Statistics, September: 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 September and is based upon 2400 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 show increasing swell sizes and red illustrates biggest swells greater than >3m (>10ft). In either graph, the area of any colour is proportional to how commonly that size swell was forecast.
The diagram implies that the most common swell direction, shown by the biggest spokes, was WNW, whereas the the prevailing 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 32% of the time, equivalent to 10 days. Open sea swells exceeding >3m (>10ft) are unlikely to occur in a normal September but 10% of the time you can expect swell in the range 1.3-2m (4-6.5ft) 10%, equivalent to (3 days). Taking into account the fraction 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 32% of the time and that surf is spoilt by onshore wind 56% of the time. This is means that we expect 26 days with waves in a typical September, of which 10 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.