Statistiques de Houle pour Arrieta, Juillet: Vagues avec Vents Légers ou Favorables.
This image shows only the swells directed at Arrieta that coincided with light winds or offshore conditions through a typical July and is based upon 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 represent increasing swell sizes and red represents the highest swells, greater than >3m (>10ft). In each graph, the area of any colour is proportional to how often that size swell occurs.
The diagram indicates that the prevailing swell direction, shown by the largest spokes, was N, 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 0.2% of the time, equivalent to 0 days. Open sea swells exceeding >3m (>10ft) are unlikely to happen in a normal July. Taking into account the proportion of these swells that coincided with expected offshore winds, and given the fact that Arrieta is quite sheltered from open water swells, we think that that clean surf can be found at Arrieta about 0.2% of the time and that surf is blown out by onshore wind 25% of the time. This is means that we expect 8 days with waves in a typical July, of which 0 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.