Ackergill Swell Statistics, Agosto: Surf with Light or Offshore Winds
The rose diagram shows only the swells directed at Ackergill that coincided with light winds or offshore conditions through a typical August. 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 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 largest swells greater than >3m (>10ft) are shown in red. 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 largest spokes, was N, whereas the the most common wind blows from the SW. 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 9% of the time, equivalent to 3 days. Open sea swells exceeding >3m (>10ft) are unlikely to occur in a normal August. Taking into account the fraction of these swells that coincided with forecast offshore winds, and given the fact that Ackergill is exposed to open water swells, we estimate that clean surf can be found at Ackergill about 9% of the time and that surf is blown out by onshore wind 12% of the time. This is means that we expect 7 days with waves in a typical August, of which 3 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.