Aropaonui Swell Statistics, August: Surf with Light or Offshore Winds
The rose diagram shows only the swells directed at Aropaonui that coincided with light winds or offshore conditions through a typical August. 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 shows the biggest swells, greater than >3m (>10ft). In both graphs, the area of any colour is proportional to how often that size swell occurs.
The diagram indicates that the dominant swell direction, shown by the largest 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 38% of the time, equivalent to 12 days. Open sea swells exceeding >3m (>10ft) are unlikely to happen in a normal August but 6% of the time you can expect swell in the range 1.3-2m (4-6.5ft) 6%, equivalent to (2 days). Taking into account the proportion 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 38% of the time and that surf is blown out by onshore wind 35% of the time. This is means that we expect 23 days with waves in a typical August, of which 12 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.