Aropaonui Swell Statistics, Winter: Surf with Light or Offshore Winds
This image shows only the swells directed at Aropaonui that coincided with light winds or offshore conditions over a normal southern hemisphere winter. It is based on 7266 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 each graph, the area of any colour is proportional to how frequently that size swell happens.
The diagram suggests that the most common swell direction, shown by the biggest spokes, was ESE, whereas the the prevailing wind blows from the WNW. 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 39% of the time, equivalent to 35 days. Open sea swells exceeding >3m (>10ft) are unlikely to arise in a normal southern hemisphere winter but 1.8% of the time we expect swell in the range 2-3m (6.5-10ft) 1.8%, equivalent to (2 days). Taking into account the fraction of these swells that coincided with forecast offshore winds, and given the fact that Aropaonui is exposed to open water swells, we estimate that clean surf can be found at Aropaonui about 39% of the time and that surf is spoilt by onshore wind 38% of the time. This is means that we expect 70 days with waves in a typical southern hemisphere winter, of which 35 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.