Agucadoura Swell Statistics, Autumn: All Swell – Any Wind
This picture shows the range of swells directed at Agucadoura through an average northern hemisphere autumn, based on 7252 NWW3 model predictions since 2006 (values every 3 hours). The wave model does not forecast wind or surf right at the coast so we have chosen the best grid node based on what we know about Agucadoura, and at Agucadoura the best grid node is 19 km away (12 miles).
The rose diagram shows the distribution of swell directions and swell sizes, while the graph at the bottom shows the same thing but lacks direction information. Five colours illustrate increasing wave sizes. Blue shows the smallest swells, less that 0.5m (1.5 feet) high. These happened only 5% of the time. Green and yellow show increasing swell sizes and red illustrates biggest swells greater than >3m (>10ft). In both graphs, the area of any colour is proportional to how often that size swell was forecast.
The diagram indicates that the prevailing swell direction, shown by the biggest spokes, was WNW, whereas the the prevailing wind blows from the N. Because the wave model grid is out to sea, sometimes a strong offshore wind blows largest waves away from Agucadoura and offshore. We group these with the no surf category of the bar chart. To simplify things we don't show these in the rose graph. Because wind determines whether or not waves are clean enough to surf at Agucadoura, you can load a different image that shows only the swells that were expected to coincide with glassy or offshore wind conditions. In a typical northern hemisphere autumn, swells large enough to cause surfable waves at Agucadoura run for about 95% of the time.
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.