Ardnave Point and Bay (Islay) Swell Statistics, Winter: 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 through a typical northern hemisphere winter and is based upon 6931 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 show increasing swell sizes and red represents the largest swells, greater than >3m (>10ft). In each graph, the area of any colour is proportional to how commonly that size swell happens.
The diagram implies that the prevailing swell direction, shown by the longest spokes, was W, whereas the the most common 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 28% of the time, equivalent to 25 days. Expect open water swells to exceed >3m (>10ft) 10% of the time (9 days). Taking into account the proportion 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 28% of the time and that surf is messed up by onshore wind 34% of the time. This is means that we expect 56 days with waves in a typical northern hemisphere winter, of which 25 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.