Arrifana Swell Statistics, All Year: Surf with Light or Offshore Winds
This image shows only the swells directed at Arrifana that coincided with light winds or offshore conditions through a typical year. It is based on 28044 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 biggest swells greater than >3m (>10ft) are shown in red. In both graphs, 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 largest spokes, was NW, whereas the the prevailing wind blows from the NNW. 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 30% of the time, equivalent to 110 days. Expect open water swells to exceed >3m (>10ft) 1.1% of the time (4 days). Taking into account the proportion of these swells that coincided with expected offshore winds, and given the fact that Arrifana is slightly protected from open water swells, we estimate that clean surf can be found at Arrifana about 30% of the time and that surf is spoilt by onshore wind 34% of the time. This is means that we expect 234 days with waves in a typical year, of which 110 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.