Statistiques de Houle pour Ammonias, Été: Vagues avec Vents Légers ou Favorables.
This image shows only the swells directed at Ammonias that coincided with light winds or offshore conditions over a normal northern hemisphere summer and is based upon 7266 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 highest swells greater than >3m (>10ft) are shown in red. In both graphs, the area of any colour is proportional to how often that size swell happens.
The diagram indicates that the most common swell direction, shown by the largest spokes, was S, whereas the the dominant wind blows from the ENE. 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 0.5% of the time, equivalent to 0 days. Open sea swells exceeding >3m (>10ft) are unlikely to arise in a normal northern hemisphere summer. Taking into account the proportion of these swells that coincided with expected offshore winds, and given the fact that Ammonias is exposed to open water swells, we estimate that clean surf can be found at Ammonias about 0.5% of the time and that surf is messed up by onshore wind 28% of the time. This is means that we expect 26 days with waves in a typical northern hemisphere summer, of which 0 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.