Ackergill Swell Statistics, Maio: 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 May. It is based on 2200 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 largest swells greater than >3m (>10ft) are shown in red. In both graphs, the area of any colour is proportional to how frequently that size swell was forecast.
The diagram suggests that the dominant swell direction, shown by the longest spokes, was N, whereas the the most common wind blows from the S. 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 8% of the time, equivalent to 2 days. Open sea swells exceeding >3m (>10ft) are unlikely to occur in a normal May. Taking into account the proportion 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 8% of the time and that surf is blown out by onshore wind 13% of the time. This is means that we expect 7 days with waves in a typical May, of which 2 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.