Aligator Rock Swell Statistics, December: Surf with Light or Offshore Winds
This image shows only the swells directed at Aligator Rock that coincided with light winds or offshore conditions through a typical December and is based upon 2457 predictions, one every 3 hours. The direction of the spokes show where quality surf generating swell comes from. Five colours represent increasing wave sizes. Very small swells of less than 0.5m (1.5 feet) high are shown in blue. Green and yellow illustrate increasing swell sizes and red represents largest swells greater than >3m (>10ft). In each graph, the area of any colour is proportional to how frequently that size swell happens.
The diagram suggests that the dominant swell direction, shown by the longest spokes, was NNW, whereas the the most common wind blows from the E. 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 52% of the time, equivalent to 16 days. Expect open water swells to exceed >3m (>10ft) 12% of the time (4 days). Taking into account the fraction of these swells that coincided with predicted offshore winds, and given the fact that Aligator Rock is exposed to open water swells, we estimate that clean surf can be found at Aligator Rock about 52% of the time and that surf is blown out by onshore wind 13% of the time. This is means that we expect 20 days with waves in a typical December, of which 16 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.