Cat Bay (Shelly Beach) Surf Stats

The figure shows the variation of swells directed at Cat Bay (Shelly Beach) through an average October, based on 3471 NWW3 model predictions since 2006 (values every 3 hours). The wave model does not forecast wind or surf right at the coast so we have chosen the most applicable grid node based on what we know about Cat Bay (Shelly Beach), and at Cat Bay (Shelly Beach) the best grid node is 12 km away (7 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 show increasing wave sizes. The smallest swells, less than 0.5m (1.5 feet), high are coloured blue. These were forecast only 3% of the time. Green and yellow show increasing swell sizes and red represents 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 longest spokes, was SW, whereas the the prevailing wind blows from the WSW. Because the wave model grid is out to sea, sometimes a strong offshore wind blows largest waves away from Cat Bay (Shelly Beach) and offshore. We combine these with the no surf category of the bar chart. To simplify things we don't show these in the rose graph. Because wind determines whether or not waves are good for surfing at Cat Bay (Shelly Beach), you can view an alternative image that shows only the swells that were expected to coincide with glassy or offshore wind conditions. In a typical October, swells large enough to cause clean enough to surf waves at Cat Bay (Shelly Beach) run for about 22% of the time.

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