Asilomar Swell Statistics, October: Surf with Light or Offshore Winds
This image shows only the swells directed at Asilomar that coincided with light winds or offshore conditions through a typical October. It is based on 2480 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 the biggest 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 WNW, whereas the the prevailing wind blows from the NW. 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 occur in a normal October but 14% of the time we expect swell in the range 2-3m (6.5-10ft) 14%, equivalent to (4 days). Taking into account the fraction of these swells that coincided with predicted offshore winds, and given the fact that Asilomar is exposed to open water swells, we think that that clean surf can be found at Asilomar about 37% of the time and that surf is spoilt by onshore wind 56% of the time. This is means that we expect 29 days with waves in a typical October, of which 11 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.