Anse de Cabestan Swell Statistics, Winter: Surf with Light or Offshore Winds
The rose diagram shows only the swells directed at Anse de Cabestan that coincided with light winds or offshore conditions through a typical northern hemisphere winter. It is based on 6931 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 shows biggest swells greater than >3m (>10ft). In each graph, the area of any colour is proportional to how frequently that size swell was forecast.
The diagram suggests that the most common swell direction, shown by the biggest spokes, was W (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 23% of the time, equivalent to 21 days. Open water swells exceeding >3m (>10ft) only occur 1.2% of the time in a typical northern hemisphere winter, equivalent to just one day but 6% of the time we expect swell in the range 2-3m (6.5-10ft) 6%, equivalent to (5 days). Taking into account the ratio of these swells that coincided with predicted offshore winds, and given the fact that Anse de Cabestan is exposed to open water swells, we think that that clean surf can be found at Anse de Cabestan about 23% of the time and that surf is spoilt by onshore wind 68% of the time. This is means that we expect 83 days with waves in a typical northern hemisphere winter, of which 21 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.