San Miguel - Areias Swell Statistics, Winter: All Swell – Any Wind
The graph illustrates the combination of swells directed at San Miguel - Areias through an average northern hemisphere winter and is based upon 6931 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 most applicable grid node based on what we know about San Miguel - Areias. In the case of San Miguel - Areias, the best grid node is 21 km away (13 miles).
The rose diagram illustrates 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 occurred only 24% of the time. Green and yellow represent 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 frequently that size swell was forecast.
The diagram suggests that the prevailing swell direction, shown by the biggest spokes, was NW, whereas the the most common wind blows from the SW. Because the wave model grid is away from the coast, sometimes a strong offshore wind blows largest waves away from San Miguel - Areias and out to sea. We group these with the no surf category of the bar chart. To simplify things we don't show these in the rose diagram. Because wind determines whether or not waves are clean enough to surf at San Miguel - Areias, you can view an alternative image that shows only the swells that were predicted to coincide with glassy or offshore wind conditions. In a typical northern hemisphere winter, swells large enough to cause surfable waves at San Miguel - Areias run for about 73% 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.