Teahupoo Swell Statistics, April: Surf with Light or Offshore Winds
This image shows only the swells directed at Teahupoo that coincided with light winds or offshore conditions through a typical April. It is based on 2160 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 represent increasing swell sizes and red represents biggest swells greater than >3m (>10ft). In each graph, the area of any colour is proportional to how commonly that size swell occurs.
The diagram implies that the prevailing swell direction, shown by the biggest spokes, was S, whereas the the prevailing wind blows from the E. 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 49% of the time, equivalent to 15 days. Open sea swells exceeding >3m (>10ft) are unlikely to happen in a normal April but 23% of the time we expect swell in the range 2-3m (6.5-10ft) 23%, equivalent to (7 days). Taking into account the fraction of these swells that coincided with predicted offshore winds, and given the fact that Teahupoo is exposed to open water swells, we estimate that clean surf can be found at Teahupoo about 49% of the time and that surf is blown out by onshore wind 50% of the time. This is means that we expect 30 days with waves in a typical April, of which 15 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.