Statistiques de Surf de Pontinha

The figure shows the combination of swells directed at Pontinha over a normal August. It is based on 3590 NWW3 model predictions since 2006 (values every 3 hours). The wave model does not forecast wind and surf right at the coast so we have chosen the most applicable grid node based on what we know about Pontinha. In this particular case the best grid node is 8 km away (5 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 2% of the time. Green and yellow show increasing swell sizes and biggest swells greater than >3m (>10ft) are shown in red. In both graphs, the area of any colour is proportional to how commonly that size swell occurs. The diagram implies that the prevailing swell direction, shown by the largest spokes, was NW, whereas the the prevailing wind blows from the NNW. Because the wave model grid is out to sea, sometimes a strong offshore wind blows largest waves away from Pontinha and offshore. We combine these with the no surf category of the bar chart. To keep it simple we don't show these in the rose plot. Because wind determines whether or not waves are clean enough to surf at Pontinha, you can select a similar diagram that shows only the swells that were predicted to coincide with glassy or offshore wind conditions. During a typical August, swells large enough to cause surfable waves at Pontinha run for about 98% of the time.

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