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Rate Xiyong Bay


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Xiyong Bay Swell Statistics, May: All Swell – Any Wind

This image describes the variation of swells directed at Xiyong Bay through a typical May, based on 2837 NWW3 model predictions since 2007 (values every 3 hours). The wave model does not forecast wind and surf right at the coastline so we have chosen the optimum grid node based on what we know about Xiyong Bay, and at Xiyong Bay the best grid node is 5 km away (3 miles).

The rose diagram illustrates 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 50% of the time. Green and yellow represent increasing swell sizes and red illustrates the highest swells, greater than >3m (>10ft). In each graph, the area of any colour is proportional to how commonly that size swell occurs.

The diagram implies that the prevailing swell direction, shown by the biggest spokes, was SE (which was the same as the dominant wind direction). Because the wave model grid is out to sea, sometimes a strong offshore wind blows largest waves away from Xiyong Bay and offshore. 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 Xiyong Bay, you can select a similar diagram that shows only the swells that were predicted to coincide with glassy or offshore wind conditions. Over an average May, swells large enough to cause clean enough to surf waves at Xiyong Bay run for about 50% of the time.

IMPORTANT: Beta version feature! Swell heights are open water values from NWW3. There is no attempt to model near-shore effects. Coastal wave heights will generally be less, especially if the break does not have unobstructed exposure to the open ocean.

FEATURE UPDATE: we now show red swell icons for 'open sea' swells that are travelling in an unfavourable direction for the surf break. In places, these swells may still wrap around coastlines and produce smaller waves at some breaks. They are also significant for windsurfers and other water users that tend to venture further off-shore.