Aberffraw Golf Statistieken, Lente: Golven met Licht of Offshore Winden
This image shows only the swells directed at Aberffraw that coincided with light winds or offshore conditions through a typical northern hemisphere spring. It is based on 6578 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 show increasing swell sizes and red represents highest swells greater than >3m (>10ft). In either graph, the area of any colour is proportional to how commonly that size swell happens.
The diagram implies that the dominant swell direction, shown by the biggest spokes, was SW, whereas the the dominant wind blows from the WSW. 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 3% of the time, equivalent to 3 days. Open sea swells exceeding >3m (>10ft) are unlikely to arise in a normal northern hemisphere spring. Taking into account the ratio of these swells that coincided with predicted offshore winds, and given the fact that Aberffraw is exposed to open water swells, we estimate that clean surf can be found at Aberffraw about 3% of the time and that surf is messed up by onshore wind 32% of the time. This is means that we expect 32 days with waves in a typical northern hemisphere spring, of which 3 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.