Asu Swell Statistics, Ottobre: Surf with Light or Offshore Winds
The rose diagram shows only the swells directed at Asu 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 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 illustrates the largest swells, greater than >3m (>10ft). In either graph, the area of any colour is proportional to how commonly that size swell was forecast.
The diagram implies that the most common swell direction, shown by the biggest spokes, was SSW, whereas the the most common wind blows from the WSW. 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 69% of the time, equivalent to 21 days. Open sea swells exceeding >3m (>10ft) are unlikely to occur in a normal October but 9% of the time we expect swell in the range 2-3m (6.5-10ft) 9%, equivalent to (3 days). Taking into account the ratio of these swells that coincided with predicted offshore winds, and given the fact that Asu is exposed to open water swells, we estimate that clean surf can be found at Asu about 69% of the time and that surf is spoilt by onshore wind 31% of the time. This is means that we expect 31 days with waves in a typical October, of which 21 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.