Ronco do Mar Surf Stats

The rose diagram describes the combination of swells directed at Ronco do Mar over a normal June. It is based on 3266 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 Ronco do Mar. In the case of Ronco do Mar, the best grid node is 45 km away (28 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 show increasing wave sizes. The smallest swells, less than 0.5m (1.5 feet), high are coloured blue. These happened only 76% of the time. Green and yellow represent increasing swell sizes and highest swells greater than >3m (>10ft) are shown in red. In each graph, the area of any colour is proportional to how often that size swell was forecast. The diagram indicates that the prevailing swell direction, shown by the biggest spokes, was NNE, whereas the the dominant wind blows from the ESE. Because the wave model grid is out to sea, sometimes a strong offshore wind blows largest waves away from Ronco do Mar and offshore. We lump these in 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 surfable at Ronco do Mar, 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 June, swells large enough to cause good for surfing waves at Ronco do Mar run for about 24% of the time.

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