Statistiques de Surf de Ixtapa

The figure shows the variation of swells directed at Ixtapa over a normal September. It is based on 3360 NWW3 model predictions since 2006 (values every 3 hours). The wave model does not forecast wind or surf right at the coastline so we have chosen the most applicable grid node based on what we know about Ixtapa, and at Ixtapa the best grid node is 21 km away (13 miles). The rose diagram shows the distribution of swell directions and swell sizes, while the graph at the bottom shows the same thing but without direction information. Five colours illustrate increasing wave sizes. Blue shows the smallest swells, less that 0.5m (1.5 feet) high. These happened only 1.3% of the time. Green and yellow represent increasing swell sizes and red represents the biggest swells, greater than >3m (>10ft). In both graphs, the area of any colour is proportional to how frequently that size swell happens. The diagram suggests that the prevailing swell direction, shown by the biggest spokes, was SSW, whereas the the prevailing wind blows from the ENE. Because the wave model grid is offshore, sometimes a strong offshore wind blows largest waves away from Ixtapa and away from the coast. We combine these with the no surf category of the bar chart. To avoid confusion we don't show these in the rose plot. Because wind determines whether or not waves are clean enough to surf at Ixtapa, you can view an alternative image that shows only the swells that were expected to coincide with glassy or offshore wind conditions. During a typical September, swells large enough to cause surfable waves at Ixtapa run for about 99% of the time.

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