Arpoador Swell Statistics, Winter: Surf with Light or Offshore Winds
The rose diagram shows only the swells directed at Arpoador that coincided with light winds or offshore conditions through a typical southern hemisphere winter 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 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 highest swells greater than >3m (>10ft) are shown in red. In each graph, the area of any colour is proportional to how frequently that size swell occurs.
The diagram suggests that the dominant swell direction, shown by the largest spokes, was SSE, whereas the the dominant wind blows from the NE. 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 30% of the time, equivalent to 27 days. Open sea swells exceeding >3m (>10ft) are unlikely to happen in a normal southern hemisphere winter but 7% of the time we expect swell in the range 2-3m (6.5-10ft) 7%, equivalent to (6 days). Taking into account the fraction of these swells that coincided with predicted offshore winds, and given the fact that Arpoador is slightly protected from open water swells, we think that that clean surf can be found at Arpoador about 30% of the time and that surf is messed up by onshore wind 19% of the time. This is means that we expect 45 days with waves in a typical southern hemisphere winter, of which 27 days should be surfable.
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.