Acid Drops Swell Statistics, September: 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 September and is based upon 2400 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 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 prevailing swell direction, shown by the biggest spokes, was S, whereas the the most common 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 37% of the time, equivalent to 11 days. Open sea swells exceeding >3m (>10ft) are unlikely to arise in a normal September but 28% of the time you can expect swell in the range 1.3-2m (4-6.5ft) 28%, equivalent to (8 days). Taking into account the fraction of these swells that coincided with forecast 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 37% of the time and that surf is spoilt by onshore wind 1.0% of the time. This is means that we expect 11 days with waves in a typical September, of which 11 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.