This image shows only the swells directed at S-Turns that coincided with light winds or offshore conditions through a typical April. It is based on 1646 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 shows the biggest swells, greater than >3m (>10ft). In both graphs, the area of any colour is proportional to how frequently that size swell happens.
The diagram suggests that the prevailing swell direction, shown by the biggest spokes, was ESE, whereas the the prevailing wind blows from the W. 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 18% of the time, equivalent to 5 days. Open sea swells exceeding >3m (>10ft) are unlikely to arise in a normal April but 7% of the time you can expect swell in the range 1.3-2m (4-6.5ft) 7%, equivalent to (2 days). Taking into account the ratio of these swells that coincided with forecast offshore winds we calculate that clean surf can be found at S-Turns about 18% of the time and that surf is messed up by onshore wind 31% of the time. This is means that we expect 15 days with waves in a typical April, of which 5 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.