Arenillas Negras Swell Statistics, February: All Swell – Any Wind
This picture shows the range of swells directed at Arenillas Negras through a typical February. It is based on 2102 NWW3 model predictions since 2007 (values every 3 hours). The wave model does not forecast wind and surf right at the shore so we have chosen the optimum grid node based on what we know about Arenillas Negras. In the case of Arenillas Negras, the best grid node is 19 km away (12 miles).
The rose diagram illustrates the distribution of swell sizes and directions, 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 were forecast only 0% of the time. Green and yellow illustrate 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 largest spokes, was SW, whereas the the prevailing wind blows from the SSW. Because the wave model grid is out to sea, sometimes a strong offshore wind blows largest waves away from Arenillas Negras and offshore. We combine these with the no surf category of the bar chart. To avoid confusion we don't show these in the rose graph. Because wind determines whether or not waves are good for surfing at Arenillas Negras, 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 February, swells large enough to cause clean enough to surf waves at Arenillas Negras run for about 100% 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.