Ahu Ahu Road Swell Statistics, October: Surf with Light or Offshore Winds
The rose diagram shows only the swells directed at Ahu Ahu Road that coincided with light winds or offshore conditions through a typical October. It is based on 2480 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 illustrate increasing swell sizes and red illustrates 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 largest spokes, was WSW (which was the same as the dominant wind direction). 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 18% of the time, equivalent to 6 days. Open sea swells exceeding >3m (>10ft) are unlikely to arise in a normal October but 6% of the time we expect swell in the range 2-3m (6.5-10ft) 6%, equivalent to (2 days). Taking into account the ratio of these swells that coincided with predicted offshore winds, and given the fact that Ahu Ahu Road is exposed to open water swells, we calculate that clean surf can be found at Ahu Ahu Road about 18% of the time and that surf is messed up by onshore wind 77% of the time. This is means that we expect 29 days with waves in a typical October, of which 6 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.