Aisling's Beach Swell Statistics, Autumn: Surf with Light or Offshore Winds
This image shows only the swells directed at Aisling's Beach that coincided with light winds or offshore conditions over a normal southern hemisphere autumn. It is based on 6580 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 illustrates the highest swells, greater than >3m (>10ft). In both graphs, the area of any colour is proportional to how frequently that size swell was forecast.
The diagram suggests that the most common swell direction, shown by the biggest spokes, was SE, whereas the the dominant 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 48% of the time, equivalent to 44 days. Open sea swells exceeding >3m (>10ft) are unlikely to occur in a normal southern hemisphere autumn 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 fraction of these swells that coincided with predicted offshore winds, and given the fact that Aisling's Beach is exposed to open water swells, we calculate that clean surf can be found at Aisling's Beach about 48% of the time and that surf is blown out by onshore wind 22% of the time. This is means that we expect 64 days with waves in a typical southern hemisphere autumn, of which 44 days should be clean enough to surf.
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.