Agucadoura Swell Statistics, May: Surf with Light or Offshore Winds
The rose diagram shows only the swells directed at Agucadoura that coincided with light winds or offshore conditions over a normal 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 illustrate increasing wave sizes. Blue shows the smallest swells, less that 0.5m (1.5 feet) high. Green and yellow illustrate increasing swell sizes and red illustrates the highest swells, greater than >3m (>10ft). In either graph, the area of any colour is proportional to how frequently that size swell occurs.
The diagram suggests that the dominant swell direction, shown by the longest spokes, was WNW, whereas the the dominant wind blows from the NW. 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 22% of the time, equivalent to 7 days. Open sea swells exceeding >3m (>10ft) are unlikely to happen in a normal May but 10% of the time you can expect swell in the range 1.3-2m (4-6.5ft) 10%, equivalent to (3 days). Taking into account the ratio of these swells that coincided with forecast offshore winds, and given the fact that Agucadoura is exposed to open water swells, we calculate that clean surf can be found at Agucadoura about 22% of the time and that surf is blown out by onshore wind 72% of the time. This is means that we expect 29 days with waves in a typical May, of which 7 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.