Avoca Point Swell Statistics, Summer: Surf with Light or Offshore Winds
This image shows only the swells directed at Avoca Point that coincided with light winds or offshore conditions over a normal southern hemisphere summer. It is based on 6931 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 show increasing swell sizes and largest swells greater than >3m (>10ft) are shown in red. In each graph, the area of any colour is proportional to how commonly that size swell occurs.
The diagram implies that the prevailing swell direction, shown by the longest spokes, was E (which was the same as the most common wind direction). 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 17% of the time, equivalent to 15 days. Open sea swells exceeding >3m (>10ft) are unlikely to happen in a normal southern hemisphere summer but 3% of the time we expect swell in the range 2-3m (6.5-10ft) 3%, equivalent to (3 days). Taking into account the fraction of these swells that coincided with expected offshore winds, and given the fact that Avoca Point is exposed to open water swells, we calculate that clean surf can be found at Avoca Point about 17% of the time and that surf is blown out by onshore wind 56% of the time. This is means that we expect 66 days with waves in a typical southern hemisphere summer, of which 15 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.