Agnes Waters Swell Statistics, Autumn: Surf with Light or Offshore Winds
This image shows only the swells directed at Agnes Waters that coincided with light winds or offshore conditions through a typical southern hemisphere autumn. It is based on 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 represent increasing swell sizes and red illustrates the largest swells, greater than >3m (>10ft). In each graph, the area of any colour is proportional to how commonly that size swell happens.
The diagram implies that the most common swell direction, shown by the biggest spokes, was E, whereas the the most common wind blows from the SE. 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 12% of the time, equivalent to 11 days. Open sea swells exceeding >3m (>10ft) are unlikely to arise in a normal southern hemisphere autumn. Taking into account the ratio of these swells that coincided with predicted offshore winds, and given the fact that Agnes Waters is exposed to open water swells, we think that that clean surf can be found at Agnes Waters about 12% of the time and that surf is blown out by onshore wind 55% of the time. This is means that we expect 61 days with waves in a typical southern hemisphere autumn, of which 11 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.