Umzumbe Surf Stats

This image shows the combination of swells directed at Umzumbe through a typical October. It is based on 3471 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 optimum grid node based on what we know about Umzumbe. In the case of Umzumbe, the best grid node is 33 km away (21 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 60% of the time. Green and yellow illustrate increasing swell sizes and biggest swells greater than >3m (>10ft) are shown in red. In both graphs, the area of any colour is proportional to how frequently that size swell occurs. The diagram suggests that the most common swell direction, shown by the largest spokes, was SSW, whereas the the prevailing wind blows from the ESE. Because the wave model grid is away from the coast, sometimes a strong offshore wind blows largest waves away from Umzumbe and out to sea. We lump these in with the no surf category of the bar chart. To simplify things we don't show these in the rose plot. Because wind determines whether or not waves are surfable at Umzumbe, you can load a different image that shows only the swells that were forecast to coincide with glassy or offshore wind conditions. Over an average October, swells large enough to cause good for surfing waves at Umzumbe run for about 39% of the time.

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