Anse de Cabestan Swell Statistics, April: 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 April and is based upon 2160 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 represent increasing swell sizes and red represents the biggest swells, greater than >3m (>10ft). 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 biggest spokes, was W, whereas the the prevailing wind blows from the N. 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 34% of the time, equivalent to 10 days. Open sea swells exceeding >3m (>10ft) are unlikely to arise in a normal April but 12% of the time you can expect swell in the range 1.3-2m (4-6.5ft) 12%, equivalent to (4 days). Taking into account the fraction of these swells that coincided with forecast offshore winds, and given the fact that Anse de Cabestan is exposed to open water swells, we calculate that clean surf can be found at Anse de Cabestan about 34% of the time and that surf is blown out by onshore wind 48% of the time. This is means that we expect 25 days with waves in a typical April, of which 10 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.