Aticama Swell Statistics, Summer: Surf with Light or Offshore Winds
This image shows only the swells directed at Aticama that coincided with light winds or offshore conditions over a normal northern hemisphere summer 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 represent increasing wave sizes. Very small swells of less than 0.5m (1.5 feet) high are shown in blue. Green and yellow represent increasing swell sizes and largest swells greater than >3m (>10ft) are shown in red. 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 longest spokes, was SSW, whereas the the most common wind blows from the W. 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 54% of the time, equivalent to 49 days. Open sea swells exceeding >3m (>10ft) are unlikely to arise in a normal northern hemisphere summer but 7% of the time you can expect swell in the range 1.3-2m (4-6.5ft) 7%, equivalent to (6 days). Taking into account the ratio of these swells that coincided with expected offshore winds, and given the fact that Aticama is exposed to open water swells, we estimate that clean surf can be found at Aticama about 54% of the time and that surf is blown out by onshore wind 39% of the time. This is means that we expect 85 days with waves in a typical northern hemisphere summer, of which 49 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.