Arpoador Swell Statistics, Summer: 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 summer and is based upon 6931 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 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 commonly that size swell happens.
The diagram implies that the most common swell direction, shown by the biggest spokes, was SE, whereas the the dominant wind blows from the ENE. 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 15% of the time, equivalent to 14 days. Open sea swells exceeding >3m (>10ft) are unlikely to arise in a normal southern hemisphere summer but 2% of the time we expect swell in the range 2-3m (6.5-10ft) 2%, equivalent to (2 days). Taking into account the proportion of these swells that coincided with expected 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 15% of the time and that surf is blown out by onshore wind 9% of the time. This is means that we expect 22 days with waves in a typical southern hemisphere summer, of which 14 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.