Aisling's Beach Swell Statistics, Winter: Surf with Light or Offshore Winds
The rose diagram shows only the swells directed at Aisling's Beach that coincided with light winds or offshore conditions over a normal southern hemisphere winter and is based upon 7266 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 illustrate increasing swell sizes and red represents the highest swells, greater than >3m (>10ft). In both graphs, the area of any colour is proportional to how often that size swell happens.
The diagram indicates that the prevailing 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 51% of the time, equivalent to 46 days. Open water swells exceeding >3m (>10ft) only arise 0.8% of the time in a typical southern hemisphere winter, equivalent to just one day but 7% of the time we expect swell in the range 2-3m (6.5-10ft) 7%, equivalent to (6 days). Taking into account the proportion of these swells that coincided with predicted offshore winds, and given the fact that Aisling's Beach is exposed to open water swells, we estimate that clean surf can be found at Aisling's Beach about 51% of the time and that surf is messed up by onshore wind 17% of the time. This is means that we expect 62 days with waves in a typical southern hemisphere winter, of which 46 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.