Playa de San Lorenzo Swell Statistics, Autumn: All Swell – Any Wind
The graph illustrates the combination of swells directed at Playa de San Lorenzo through a typical northern hemisphere autumn. It is based on 6516 NWW3 model predictions since 2006 (values every 3 hours). The wave model does not forecast wind and surf right at the shore so we have chosen the best grid node based on what we know about Playa de San Lorenzo, and at Playa de San Lorenzo the best grid node is 53 km away (33 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 show increasing wave sizes. The smallest swells, less than 0.5m (1.5 feet), high are coloured blue. These happened only 9% of the time. Green and yellow show increasing swell sizes and largest swells greater than >3m (>10ft) are shown in red. In each graph, the area of any colour is proportional to how commonly that size swell happens.
The diagram implies that the dominant swell direction, shown by the largest spokes, was NW, whereas the the most common wind blows from the N. Because the wave model grid is away from the coast, sometimes a strong offshore wind blows largest waves away from Playa de San Lorenzo and out to sea. We group these with the no surf category of the bar chart. To keep it simple we don't show these in the rose graph. Because wind determines whether or not waves are good for surfing at Playa de San Lorenzo, you can load a different image that shows only the swells that were predicted 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 Playa de San Lorenzo run for about 75% 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.