Arrieta Swell Statistics, All Year: Surf with Light or Offshore Winds
This image shows only the swells directed at Arrieta that coincided with light winds or offshore conditions over a normal year. It is based on 28044 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 highest swells greater than >3m (>10ft) are shown in red. In each graph, the area of any colour is proportional to how frequently that size swell was forecast.
The diagram suggests that the prevailing swell direction, shown by the largest spokes, was NNW, whereas the the dominant wind blows from the NNE. 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 4% of the time, equivalent to 15 days. Expect open water swells to exceed >3m (>10ft) 0.5% of the time (2 days). Taking into account the ratio of these swells that coincided with expected offshore winds, and given the fact that Arrieta is quite sheltered from open water swells, we estimate that clean surf can be found at Arrieta about 4% of the time and that surf is blown out by onshore wind 25% of the time. This is means that we expect 106 days with waves in a typical year, of which 15 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.