This image shows only the swells directed at The Reef that coincided with light winds or offshore conditions over a normal southern hemisphere spring. It is based on 5144 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 represent increasing swell sizes and highest swells greater than >3m (>10ft) are shown in red. In either graph, the area of any colour is proportional to how often that size swell occurs.
The diagram indicates that the prevailing swell direction, shown by the biggest spokes, was ESE, whereas the the dominant wind blows from the ENE. 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 11% of the time, equivalent to 10 days. Open sea swells exceeding >3m (>10ft) are unlikely to happen in a normal southern hemisphere spring but 3% of the time you can expect swell in the range 1.3-2m (4-6.5ft) 3%, equivalent to (3 days). Taking into account the fraction of these swells that coincided with predicted offshore winds, and given the fact that The Reef is exposed to open water swells, we think that that clean surf can be found at The Reef about 11% of the time and that surf is blown out by onshore wind 72% of the time. This is means that we expect 76 days with waves in a typical southern hemisphere spring, of which 10 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.