Aropaonui Swell Statistics, April: Surf with Light or Offshore Winds
This image shows only the swells directed at Aropaonui that coincided with light winds or offshore conditions through a typical April and is based upon 2160 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 show increasing swell sizes and red represents highest swells greater than >3m (>10ft). In either graph, the area of any colour is proportional to how often that size swell was forecast.
The diagram indicates that the prevailing swell direction, shown by the biggest spokes, was ESE, whereas the the dominant 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 43% of the time, equivalent to 13 days. Open sea swells exceeding >3m (>10ft) are unlikely to occur in a normal April 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 43% of the time and that surf is spoilt by onshore wind 38% of the time. This is means that we expect 24 days with waves in a typical April, of which 13 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.