Vanthrax Surf Stats

The rose diagram illustrates the range of swells directed at Vanthrax through a typical July. It is based on 3472 NWW3 model predictions since 2006 (values every 3 hours). The wave model does not forecast wind and surf right at the coast so we have chosen the optimum grid node based on what we know about Vanthrax, and at Vanthrax the best grid node is 24 km away (15 miles). The rose diagram describes the distribution of swell sizes and swell direction, while the graph at the bottom shows the same thing but lacks direction information. Five colours illustrate increasing wave sizes. Blue shows the smallest swells, less that 0.5m (1.5 feet) high. These were forecast only 4% of the time. Green and yellow show increasing swell sizes and red represents the largest swells, greater than >3m (>10ft). In each graph, 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 biggest spokes, was NW, whereas the the most common wind blows from the NNW. Because the wave model grid is offshore, sometimes a strong offshore wind blows largest waves away from Vanthrax and away from the coast. We lump these in with the no surf category of the bar chart. To keep it simple we don't show these in the rose plot. Because wind determines whether or not waves are surfable at Vanthrax, you can load a different image that shows only the swells that were expected to coincide with glassy or offshore wind conditions. Over an average July, swells large enough to cause good for surfing waves at Vanthrax run for about 28% of the time.

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