Statistiques de Houle pour ADs/Doubles, Automne: Vagues avec Vents Légers ou Favorables.
The rose diagram shows only the swells directed at ADs/Doubles that coincided with light winds or offshore conditions through a typical northern hemisphere autumn and is based upon 7252 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 biggest swells greater than >3m (>10ft) are shown in red. In both graphs, 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 largest spokes, was ENE (which was the same as the prevailing wind direction). 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 1.5% of the time, equivalent to 1 days. Open sea swells exceeding >3m (>10ft) are unlikely to arise in a normal northern hemisphere autumn. Taking into account the fraction of these swells that coincided with expected offshore winds, and given the fact that ADs/Doubles is exposed to open water swells, we calculate that clean surf can be found at ADs/Doubles about 1.5% of the time and that surf is messed up by onshore wind 28% of the time. This is means that we expect 27 days with waves in a typical northern hemisphere autumn, of which 1 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.