Otago Peninsula - Allans Beach Swell Statistics, All Year: Surf with Light or Offshore Winds
This image shows only the swells directed at Otago Peninsula - Allans Beach that coincided with light winds or offshore conditions through a typical year and is based upon 28044 predictions, one every 3 hours. The direction of the spokes show where quality surf generating swell comes from. Five colours illustrate increasing wave sizes. Blue shows the smallest swells, less that 0.5m (1.5 feet) high. Green and yellow represent 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 commonly that size swell was forecast.
The diagram implies that the prevailing swell direction, shown by the biggest spokes, was S, whereas the the prevailing wind blows from the NW. 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 29% of the time, equivalent to 106 days. Open sea swells exceeding >3m (>10ft) are unlikely to occur in a normal year but 2% of the time we expect swell in the range 2-3m (6.5-10ft) 2%, equivalent to (7 days). Taking into account the proportion of these swells that coincided with expected offshore winds, and given the fact that Otago Peninsula - Allans Beach is exposed to open water swells, we estimate that clean surf can be found at Otago Peninsula - Allans Beach about 29% of the time and that surf is blown out by onshore wind 39% of the time. This is means that we expect 248 days with waves in a typical year, of which 106 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.