Glenelg Rivermouth Surf Stats

This chart shows the combination of swells directed at Glenelg Rivermouth over a normal September, based on 3360 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 most applicable grid node based on what we know about Glenelg Rivermouth. In this particular case the best grid node is 44 km away (27 miles). The rose diagram shows the distribution of swell sizes and directions, while the graph at the bottom shows the same thing but 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 21% of the time. Green and yellow illustrate increasing swell sizes and red shows biggest swells greater than >3m (>10ft). In both graphs, the area of any colour is proportional to how commonly that size swell occurs. The diagram implies that the dominant swell direction, shown by the largest spokes, was SW, whereas the the prevailing wind blows from the WNW. Because the wave model grid is offshore, sometimes a strong offshore wind blows largest waves away from Glenelg Rivermouth and away from the coast. We lump these in with the no surf category of the bar chart. To avoid confusion we don't show these in the rose diagram. Because wind determines whether or not waves are good for surfing at Glenelg Rivermouth, you can view an alternative image that shows only the swells that were forecast to coincide with glassy or offshore wind conditions. During a typical September, swells large enough to cause clean enough to surf waves at Glenelg Rivermouth run for about 79% of the time.

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