Aberwystwyth Beach Swell Statistics, All Year: Surf with Light or Offshore Winds
The rose diagram shows only the swells directed at Aberwystwyth Beach that coincided with light winds or offshore conditions over a normal year. It is based on 28031 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 the largest swells, greater than >3m (>10ft). In both graphs, the area of any colour is proportional to how commonly that size swell occurs.
The diagram implies that the prevailing swell direction, shown by the longest spokes, was SW, whereas the the most common 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 2% of the time, equivalent to 7 days. Open sea swells exceeding >3m (>10ft) are unlikely to happen in a normal year but 0.5% of the time we expect swell in the range 2-3m (6.5-10ft) 0.5%, equivalent to (2 days). Taking into account the proportion of these swells that coincided with expected offshore winds, and given the fact that Aberwystwyth Beach is slightly protected from open water swells, we calculate that clean surf can be found at Aberwystwyth Beach about 2% of the time and that surf is messed up by onshore wind 23% of the time. This is means that we expect 91 days with waves in a typical year, of which 7 days should be clean enough to surf.
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.