Aligator Rock Swell Statistics, Spring: Surf with Light or Offshore Winds
The rose diagram shows only the swells directed at Aligator Rock that coincided with light winds or offshore conditions through a typical northern hemisphere spring and is based upon 6580 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 largest swells greater than >3m (>10ft). In each graph, the area of any colour is proportional to how often that size swell was forecast.
The diagram indicates that the prevailing swell direction, shown by the largest 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 39% of the time, equivalent to 35 days. Expect open water swells to exceed >3m (>10ft) 3% of the time (3 days). Taking into account the ratio of these swells that coincided with expected offshore winds, and given the fact that Aligator Rock is exposed to open water swells, we calculate that clean surf can be found at Aligator Rock about 39% of the time and that surf is messed up by onshore wind 8% of the time. This is means that we expect 43 days with waves in a typical northern hemisphere spring, of which 35 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.