Acid Drops Swell Statistics, Autumn: Surf with Light or Offshore Winds
This image shows only the swells directed at Acid Drops that coincided with light winds or offshore conditions through a typical northern hemisphere autumn. It is based on 7252 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 biggest swells greater than >3m (>10ft) are shown in red. In each graph, the area of any colour is proportional to how often that size swell was forecast.
The diagram indicates that the prevailing swell direction, shown by the largest spokes, was S, whereas the the prevailing 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 19% of the time, equivalent to 17 days. Open sea swells exceeding >3m (>10ft) are unlikely to occur in a normal northern hemisphere autumn but 14% of the time you can expect swell in the range 1.3-2m (4-6.5ft) 14%, equivalent to (13 days). Taking into account the ratio of these swells that coincided with expected offshore winds, and given the fact that Acid Drops is exposed to open water swells, we think that that clean surf can be found at Acid Drops about 19% of the time and that surf is spoilt by onshore wind 1.0% of the time. This is means that we expect 18 days with waves in a typical northern hemisphere autumn, of which 17 days should be clean enough to surf.
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.