This image shows only the swells directed at Lackan Bay that coincided with light winds or offshore conditions over a normal February. It is based on 1584 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 illustrate increasing swell sizes and red illustrates highest swells greater than >3m (>10ft). In either graph, 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 longest spokes, was WNW, whereas the the dominant wind blows from the SSW. 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 21% of the time, equivalent to 6 days. Expect open water swells to exceed >3m (>10ft) 9% of the time (3 days). Taking into account the proportion of these swells that coincided with predicted offshore winds, and given the fact that Lackan Bay is slightly protected from open water swells, we calculate that clean surf can be found at Lackan Bay about 21% of the time and that surf is blown out by onshore wind 23% of the time. This is means that we expect 12 days with waves in a typical February, of which 6 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.