Isla Grande Surf Stats

The figure describes the variation of swells directed at Isla Grande through a typical April. It is based on 3360 NWW3 model predictions since 2007 (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 Isla Grande. In the case of Isla Grande, the best grid node is 41 km away (25 miles). The rose diagram shows the distribution of swell directions and swell sizes, while the graph at the bottom shows the same thing but lacks 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 0.7% of the time. Green and yellow represent increasing swell sizes and highest swells greater than >3m (>10ft) are shown in red. 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 largest spokes, was NE, whereas the the dominant wind blows from the NNE. Because the wave model grid is away from the coast, sometimes a strong offshore wind blows largest waves away from Isla Grande and out to sea. We lump these in with the no surf category of the bar chart. To avoid confusion we don't show these in the rose graph. Because wind determines whether or not waves are clean enough to surf at Isla Grande, you can select a similar diagram that shows only the swells that were forecast to coincide with glassy or offshore wind conditions. Over an average April, swells large enough to cause surfable waves at Isla Grande run for about 70% of the time.

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