This image shows only the swells directed at Papanoa that coincided with light winds or offshore conditions over a normal October. It is based on 1736 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 red shows the largest swells, greater than >3m (>10ft). In either graph, the area of any colour is proportional to how frequently that size swell occurs.
The diagram suggests that the most common swell direction, shown by the biggest spokes, was SSW, whereas the the most common 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 45% of the time, equivalent to 14 days. Open sea swells exceeding >3m (>10ft) are unlikely to happen in a normal October but 5% of the time we expect swell in the range 2-3m (6.5-10ft) 5%, equivalent to (2 days). Taking into account the ratio of these swells that coincided with forecast offshore winds, and given the fact that Papanoa is exposed to open water swells, we think that that clean surf can be found at Papanoa about 45% of the time and that surf is spoilt by onshore wind 54% of the time. This is means that we expect 31 days with waves in a typical October, of which 14 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.