The graph shows the range of swells directed at La Esquina del Mar through a typical northern hemisphere autumn. It is based on 5144 NWW3 model predictions since 2006 (values every 3 hours). The wave model does not forecast wind or surf right at the shore so we have chosen the best grid node based on what we know about La Esquina del Mar. In the case of La Esquina del Mar, the best grid node is 44 km away (27 miles).
The rose diagram shows the distribution of swell directions and swell sizes, while the graph at the bottom shows the same thing without direction information. Five colours illustrate increasing wave sizes. Blue shows the smallest swells, less that 0.5m (1.5 feet) high. These happened only 0% of the time. Green and yellow show increasing swell sizes and red illustrates biggest swells greater than >3m (>10ft). In either graph, the area of any colour is proportional to how commonly that size swell was forecast.
The diagram implies that the dominant swell direction, shown by the biggest spokes, was SSW, whereas the the prevailing wind blows from the WSW. Because the wave model grid is away from the coast, sometimes a strong offshore wind blows largest waves away from La Esquina del Mar and out to sea. We lump these in with the no surf category of the bar chart. To avoid confusion we don't show these in the rose diagram. Because wind determines whether or not waves are good for surfing at La Esquina del Mar, you can view an alternative image that shows only the swells that were forecast to coincide with glassy or offshore wind conditions. Over an average northern hemisphere autumn, swells large enough to cause clean enough to surf waves at La Esquina del Mar run for about 9% 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.