Airport Lefts Swell Statistics, Summer: Surf with Light or Offshore Winds
This image shows only the swells directed at Airport Lefts that coincided with light winds or offshore conditions over a normal southern hemisphere summer. It is based on 6931 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 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 largest spokes, was SW, whereas the the most common wind blows from the W. 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 36% of the time, equivalent to 33 days. Open sea swells exceeding >3m (>10ft) are unlikely to happen in a normal southern hemisphere summer but 4% of the time we expect swell in the range 2-3m (6.5-10ft) 4%, equivalent to (4 days). Taking into account the proportion of these swells that coincided with forecast offshore winds, and given the fact that Airport Lefts is exposed to open water swells, we think that that clean surf can be found at Airport Lefts about 36% of the time and that surf is spoilt by onshore wind 64% of the time. This is means that we expect 91 days with waves in a typical southern hemisphere summer, of which 33 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.