Statistiques de Houle pour Ardnave Point and Bay (Islay), Septembre: Vagues avec Vents Légers ou Favorables.
This image shows only the swells directed at Ardnave Point and Bay (Islay) that coincided with light winds or offshore conditions through a typical September. It is based on 2400 predictions, one every 3 hours. The direction of the spokes show where quality surf generating swell comes from. Five colours illustrate increasing wave sizes. Blue shows the smallest swells, less that 0.5m (1.5 feet) high. Green and yellow show increasing swell sizes and red illustrates biggest swells greater than >3m (>10ft). In both graphs, the area of any colour is proportional to how frequently that size swell was forecast.
The diagram suggests that the dominant swell direction, shown by the longest spokes, was W, whereas the the prevailing 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 13% of the time, equivalent to 4 days. Open sea swells exceeding >3m (>10ft) are unlikely to occur in a normal September but 12% of the time we expect swell in the range 2-3m (6.5-10ft) 12%, equivalent to (4 days). Taking into account the ratio of these swells that coincided with expected 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 13% of the time and that surf is blown out by onshore wind 20% of the time. This is means that we expect 10 days with waves in a typical September, of which 4 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.