Aligator Rock Swell Statistics, Autumn: 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 northern hemisphere autumn and is based upon 7252 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 show increasing swell sizes and red represents the biggest swells, greater than >3m (>10ft). In both graphs, the area of any colour is proportional to how frequently that size swell was forecast.
The diagram suggests that the prevailing swell direction, shown by the longest spokes, was NNW, whereas the the prevailing 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 48% of the time, equivalent to 44 days. Expect open water swells to exceed >3m (>10ft) 6% of the time (5 days). Taking into account the proportion of these swells that coincided with forecast offshore winds, and given the fact that Aligator Rock is exposed to open water swells, we think that that clean surf can be found at Aligator Rock about 48% of the time and that surf is messed up by onshore wind 11% of the time. This is means that we expect 54 days with waves in a typical northern hemisphere autumn, of which 44 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.