Alkimos Swell Statistics, Spring: 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 spring and is based upon 7252 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 show increasing swell sizes and red represents the 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 prevailing swell direction, shown by the largest spokes, was SW, whereas the the most common wind blows from the S. 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 water swells exceeding >3m (>10ft) only occur 1.6% of the time in a typical southern hemisphere spring, equivalent to just one day 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 ratio of these swells that coincided with forecast offshore winds, and given the fact that Alkimos is exposed to open water swells, we think that that clean surf can be found at Alkimos about 28% of the time and that surf is blown out by onshore wind 72% of the time. This is means that we expect 91 days with waves in a typical southern hemisphere spring, 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.