Anglet - La Madrague Swell Statistics, Summer: Surf with Light or Offshore Winds
The rose diagram shows only the swells directed at Anglet - La Madrague that coincided with light winds or offshore conditions through a typical northern hemisphere summer. It is based on 7265 predictions, one every 3 hours. The direction of the spokes show where quality surf generating swell comes from. Five colours represent increasing wave sizes. Very small swells of less than 0.5m (1.5 feet) high are shown in blue. Green and yellow show increasing swell sizes and red illustrates the biggest swells, greater than >3m (>10ft). In each graph, the area of any colour is proportional to how often that size swell happens.
The diagram indicates that the dominant swell direction, shown by the largest spokes, was WNW, whereas the the prevailing wind blows from the NNW. 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 36% of the time, equivalent to 33 days. Open sea swells exceeding >3m (>10ft) are unlikely to arise in a normal northern hemisphere summer but 6% of the time you can expect swell in the range 1.3-2m (4-6.5ft) 6%, equivalent to (5 days). Taking into account the fraction of these swells that coincided with expected offshore winds, and given the fact that Anglet - La Madrague is exposed to open water swells, we calculate that clean surf can be found at Anglet - La Madrague about 36% of the time and that surf is messed up by onshore wind 55% of the time. This is means that we expect 83 days with waves in a typical northern hemisphere summer, of which 33 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.