Wanganui River Mouth Surf Stats

This chart illustrates the variation of swells directed at Wanganui River Mouth through a typical May. It is based on 3440 NWW3 model predictions since 2007 (values every 3 hours). The wave model does not forecast wind or surf right at the coastline so we have chosen the best grid node based on what we know about Wanganui River Mouth. In this particular case the best grid node is 42 km away (26 miles). The rose diagram illustrates the distribution of swell directions and swell sizes, while the graph at the bottom shows the same thing but lacks 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 15% of the time. Green and yellow illustrate increasing swell sizes and red represents the largest swells, greater than >3m (>10ft). In both graphs, the area of any colour is proportional to how frequently that size swell was forecast. The diagram suggests that the most common swell direction, shown by the largest spokes, was W, whereas the the most common wind blows from the NW. Because the wave model grid is away from the coast, sometimes a strong offshore wind blows largest waves away from Wanganui River Mouth 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 good for surfing at Wanganui River Mouth, 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 May, swells large enough to cause clean enough to surf waves at Wanganui River Mouth run for about 50% of the time.

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