Algarrobo Swell Statistics, Summer: Surf with Light or Offshore Winds
This image shows only the swells directed at Algarrobo that coincided with light winds or offshore conditions through a typical southern hemisphere summer. It is based on 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 show increasing swell sizes and red represents highest swells greater than >3m (>10ft). In both graphs, the area of any colour is proportional to how often that size swell occurs.
The diagram indicates that the most common swell direction, shown by the biggest spokes, was WSW, whereas the the dominant wind blows from the SW. 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 12% of the time, equivalent to 11 days. Open sea swells exceeding >3m (>10ft) are unlikely to happen in a normal southern hemisphere summer but 5% of the time we expect swell in the range 2-3m (6.5-10ft) 5%, equivalent to (5 days). Taking into account the proportion of these swells that coincided with predicted offshore winds, and given the fact that Algarrobo is exposed to open water swells, we think that that clean surf can be found at Algarrobo about 12% of the time and that surf is spoilt by onshore wind 67% of the time. This is means that we expect 72 days with waves in a typical southern hemisphere summer, of which 11 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.