ADs/Doubles Swell Statistics, Summer: Surf with Light or Offshore Winds
This image shows only the swells directed at ADs/Doubles that coincided with light winds or offshore conditions over a normal northern hemisphere summer and is based upon 7266 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 illustrate increasing swell sizes and red represents the largest swells, greater than >3m (>10ft). In either graph, the area of any colour is proportional to how frequently that size swell happens.
The diagram suggests that the most common swell direction, shown by the biggest spokes, was ENE (which was the same as the most common wind direction). 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 0.7% of the time, equivalent to 1 days. Open sea swells exceeding >3m (>10ft) are unlikely to arise in a normal northern hemisphere summer. Taking into account the proportion of these swells that coincided with expected offshore winds, and given the fact that ADs/Doubles is exposed to open water swells, we think that that clean surf can be found at ADs/Doubles about 0.7% of the time and that surf is spoilt by onshore wind 73% of the time. This is means that we expect 67 days with waves in a typical northern hemisphere summer, of which 1 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.