Alkimos Swell Statistics, Summer: Surf with Light or Offshore Winds
This image shows only the swells directed at Alkimos 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 illustrate increasing wave sizes. Blue shows the smallest swells, less that 0.5m (1.5 feet) high. Green and yellow show increasing swell sizes and red shows largest swells greater than >3m (>10ft). In both graphs, the area of any colour is proportional to how frequently that size swell was forecast.
The diagram suggests that the most common swell direction, shown by the longest spokes, was SW, whereas the the most common wind blows from the SSE. 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 28% of the time, equivalent to 25 days. Open sea swells exceeding >3m (>10ft) are unlikely to occur in a normal southern hemisphere summer but 4% of the time we expect swell in the range 2-3m (6.5-10ft) 4%, equivalent to (4 days). Taking into account the fraction of these swells that coincided with forecast offshore winds, and given the fact that Alkimos is exposed to open water swells, we estimate that clean surf can be found at Alkimos about 28% of the time and that surf is messed up by onshore wind 72% of the time. This is means that we expect 91 days with waves in a typical southern hemisphere summer, of which 25 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.