Airport Rights Swell Statistics, December: Surf with Light or Offshore Winds
The rose diagram shows only the swells directed at Airport Rights that coincided with light winds or offshore conditions over a normal December. It is based on 2457 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 illustrate increasing swell sizes and biggest swells greater than >3m (>10ft) are shown in red. In either graph, the area of any colour is proportional to how frequently that size swell occurs.
The diagram suggests that the dominant swell direction, shown by the largest spokes, was SSW, whereas the the prevailing wind blows from the WSW. 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 44% of the time, equivalent to 13 days. Open sea swells exceeding >3m (>10ft) are unlikely to happen in a normal December but 27% of the time you can expect swell in the range 1.3-2m (4-6.5ft) 27%, equivalent to (8 days). Taking into account the fraction of these swells that coincided with forecast 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 44% of the time and that surf is blown out by onshore wind 56% of the time. This is means that we expect 30 days with waves in a typical December, of which 13 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.