The graph describes the combination of swells directed at Corralito through a typical December, based on 1736 NWW3 model predictions since 2006 (values every 3 hours). The wave model does not forecast surf and wind right at the shore so we have chosen the best grid node based on what we know about Corralito. In the case of Corralito, the best grid node is 33 km away (21 miles).
The rose diagram illustrates the distribution of swell directions and swell sizes, while the graph at the bottom shows the same thing but without direction information. Five colours represent increasing wave sizes. Very small swells of less than 0.5m (1.5 feet) high are shown in blue. These happened only 41% of the time. Green and yellow illustrate increasing swell sizes and red shows highest swells greater than >3m (>10ft). In both graphs, the area of any colour is proportional to how frequently that size swell was forecast.
The diagram suggests that the most common swell direction, shown by the biggest spokes, was SSE, whereas the the dominant wind blows from the E. Because the wave model grid is out to sea, sometimes a strong offshore wind blows largest waves away from Corralito 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 plot. Because wind determines whether or not waves are surfable at Corralito, you can view an alternative image that shows only the swells that were predicted to coincide with glassy or offshore wind conditions. Over an average December, swells large enough to cause good for surfing waves at Corralito run for about 59% 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.