Ardnave Point and Bay (Islay) Swell Statistics, Autumn: Surf with Light or Offshore Winds
This image shows only the swells directed at Ardnave Point and Bay (Islay) that coincided with light winds or offshore conditions over a normal northern hemisphere autumn. It is based on 7252 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 highest swells, greater than >3m (>10ft). In either graph, the area of any colour is proportional to how often that size swell happens.
The diagram indicates that the dominant swell direction, shown by the biggest spokes, was W, whereas the the dominant wind blows from the SW. 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 19 days. Expect open water swells to exceed >3m (>10ft) 5% of the time (5 days). Taking into account the ratio of these swells that coincided with predicted offshore winds, and given the fact that Ardnave Point and Bay (Islay) is quite sheltered from open water swells, we think that that clean surf can be found at Ardnave Point and Bay (Islay) about 21% of the time and that surf is blown out by onshore wind 24% of the time. This is means that we expect 41 days with waves in a typical northern hemisphere autumn, 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.