Airport Rights Swell Statistics, September: Surf with Light or Offshore Winds
This image shows only the swells directed at Airport Rights that coincided with light winds or offshore conditions over a normal September and is based upon 2400 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 shows largest swells greater than >3m (>10ft). In each graph, the area of any colour is proportional to how commonly that size swell happens.
The diagram implies that the prevailing swell direction, shown by the biggest spokes, was SSW, whereas the the most common wind blows from the SE. 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 91% of the time, equivalent to 27 days. Open water swells exceeding >3m (>10ft) only arise 2.0% of the time in a typical September, equivalent to just one day but 58% of the time we expect swell in the range 2-3m (6.5-10ft) 58%, equivalent to (17 days). Taking into account the fraction of these swells that coincided with predicted offshore winds, and given the fact that Airport Rights is exposed to open water swells, we calculate that clean surf can be found at Airport Rights about 91% of the time and that surf is messed up by onshore wind 9% of the time. This is means that we expect 30 days with waves in a typical September, of which 27 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.