Porangahau River Mouth Surf Stats

This picture describes the range of swells directed at Porangahau River Mouth through an average July, based on 3720 NWW3 model predictions since 2006 (values every 3 hours). The wave model does not forecast wind and surf right at the coastline so we have chosen the most applicable grid node based on what we know about Porangahau River Mouth. In the case of Porangahau River Mouth, 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 without direction information. Five colours represent increasing wave sizes. Very small swells of less than 0.5m (1.5 feet) high are shown in blue. These were forecast only 38% of the time. Green and yellow represent increasing swell sizes and red illustrates the highest swells, greater than >3m (>10ft). In both graphs, the area of any colour is proportional to how often that size swell occurs. The diagram indicates that the dominant swell direction, shown by the longest spokes, was SE, whereas the the dominant wind blows from the WNW. Because the wave model grid is away from the coast, sometimes a strong offshore wind blows largest waves away from Porangahau River Mouth and out to sea. 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 diagram. Because wind determines whether or not waves are surfable at Porangahau River Mouth, you can load a different image that shows only the swells that were forecast to coincide with glassy or offshore wind conditions. In a typical July, swells large enough to cause good for surfing waves at Porangahau River Mouth run for about 62% of the time.

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