Anse a La Gourde Swell Statistics, Spring: Surf with Light or Offshore Winds
The rose diagram shows only the swells directed at Anse a La Gourde that coincided with light winds or offshore conditions through a typical northern hemisphere spring. It is based on 6580 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 illustrate increasing swell sizes and red illustrates the highest swells, greater than >3m (>10ft). In either 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 NE, whereas the the dominant wind blows from the E. 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 3% of the time, equivalent to 3 days. Open sea swells exceeding >3m (>10ft) are unlikely to arise in a normal northern hemisphere spring. Taking into account the ratio of these swells that coincided with expected offshore winds, and given the fact that Anse a La Gourde is exposed to open water swells, we estimate that clean surf can be found at Anse a La Gourde about 3% of the time and that surf is spoilt by onshore wind 94% of the time. This is means that we expect 88 days with waves in a typical northern hemisphere spring, of which 3 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.