This image shows only the swells directed at Coolum Beach that coincided with light winds or offshore conditions through a typical June and is based upon 1594 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 illustrate increasing swell sizes and red represents the biggest swells, greater than >3m (>10ft). In each graph, the area of any colour is proportional to how commonly that size swell was forecast.
The diagram implies that the most common swell direction, shown by the longest spokes, was SE, whereas the the prevailing wind blows from the S. 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 44% of the time, equivalent to 13 days. Open sea swells exceeding >3m (>10ft) are unlikely to occur in a normal June but 10% of the time we expect swell in the range 2-3m (6.5-10ft) 10%, equivalent to (3 days). Taking into account the proportion of these swells that coincided with expected offshore winds, and given the fact that Coolum Beach is exposed to open water swells, we think that that clean surf can be found at Coolum Beach about 44% of the time and that surf is blown out by onshore wind 43% of the time. This is means that we expect 26 days with waves in a typical June, of which 13 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.