Apollo Bay Swell Statistics, Spring: Surf with Light or Offshore Winds
This image shows only the swells directed at Apollo Bay that coincided with light winds or offshore conditions through a typical southern hemisphere spring. It is based on 7252 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 red illustrates the biggest 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 dominant swell direction, shown by the biggest spokes, was SW, 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 51% of the time, equivalent to 46 days. Expect open water swells to exceed >3m (>10ft) 19% of the time (17 days). Taking into account the ratio of these swells that coincided with expected offshore winds, and given the fact that Apollo Bay is slightly protected from open water swells, we calculate that clean surf can be found at Apollo Bay about 51% of the time and that surf is messed up by onshore wind 47% of the time. This is means that we expect 89 days with waves in a typical southern hemisphere spring, of which 46 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.