This image shows only the swells directed at Natadola Beach that coincided with light winds or offshore conditions through a typical July and is based upon 1736 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 represents the biggest swells, greater than >3m (>10ft). In both graphs, the area of any colour is proportional to how often that size swell was forecast.
The diagram indicates that the most common swell direction, shown by the largest spokes, was S, whereas the the prevailing wind blows from the ESE. 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 60% of the time, equivalent to 19 days. Open sea swells exceeding >3m (>10ft) are unlikely to occur in a normal July but 18% of the time we expect swell in the range 2-3m (6.5-10ft) 18%, equivalent to (6 days). Taking into account the proportion of these swells that coincided with expected offshore winds, and given the fact that Natadola Beach is exposed to open water swells, we calculate that clean surf can be found at Natadola Beach about 60% of the time and that surf is blown out by onshore wind 38% of the time. This is means that we expect 30 days with waves in a typical July, of which 19 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.