Iztapa Surf Stats

This picture shows the combination of swells directed at Iztapa through a typical July. It is based on 3720 NWW3 model predictions since 2006 (values every 3 hours). The wave model does not forecast wind or surf right at the shore so we have chosen the optimum grid node based on what we know about Iztapa. In the case of Iztapa, the best grid node is 52 km away (32 miles). The rose diagram describes the distribution of swell directions and swell sizes, while the graph at the bottom shows the same thing but without direction information. Five colours show increasing wave sizes. The smallest swells, less than 0.5m (1.5 feet), high are coloured blue. These were forecast only 0% of the time. Green and yellow show increasing swell sizes and red represents the biggest swells, greater than >3m (>10ft). In either graph, the area of any colour is proportional to how commonly that size swell was forecast. The diagram implies that the most common swell direction, shown by the largest spokes, was SSW, whereas the the prevailing wind blows from the NE. Because the wave model grid is away from the coast, sometimes a strong offshore wind blows largest waves away from Iztapa and out to sea. We combine these with the no surf category of the bar chart. To keep it simple we don't show these in the rose graph. Because wind determines whether or not waves are clean enough to surf at Iztapa, you can view an alternative image that shows only the swells that were forecast to coincide with glassy or offshore wind conditions. Over an average July, swells large enough to cause surfable waves at Iztapa run for about 100% of the time.

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