Statistiques de Surf de Itaipu

The graph describes the combination of swells directed at Itaipu through a typical July. It is based on 3720 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 Itaipu. In this particular case the best grid node is 39 km away (24 miles). The rose diagram describes 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 were forecast only 3% of the time. Green and yellow illustrate increasing swell sizes and red shows highest swells greater than >3m (>10ft). In either graph, the area of any colour is proportional to how frequently that size swell was forecast. The diagram suggests that the dominant swell direction, shown by the longest spokes, was SSE, whereas the the dominant wind blows from the ENE. Because the wave model grid is out to sea, sometimes a strong offshore wind blows largest waves away from Itaipu and offshore. We combine these with the no surf category of the bar chart. To simplify things we don't show these in the rose graph. Because wind determines whether or not waves are good for surfing at Itaipu, you can select a similar diagram that shows only the swells that were predicted to coincide with glassy or offshore wind conditions. Over an average July, swells large enough to cause clean enough to surf waves at Itaipu run for about 6% of the time.

read more