Portslade Surf Stats

This picture describes the combination of swells directed at Portslade through an average November, based on 3343 NWW3 model predictions since 2006 (values every 3 hours). The wave model does not forecast wind and surf right at the shore so we have chosen the best grid node based on what we know about Portslade. In the case of Portslade, the best grid node is 40 km away (25 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 illustrate increasing wave sizes. Blue shows the smallest swells, less that 0.5m (1.5 feet) high. These happened only 41% of the time. Green and yellow represent increasing swell sizes and highest swells greater than >3m (>10ft) are shown in red. In each graph, 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 SW, whereas the the dominant wind blows from the WSW. Because the wave model grid is out to sea, sometimes a strong offshore wind blows largest waves away from Portslade and offshore. 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 Portslade, 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 November, swells large enough to cause good for surfing waves at Portslade run for about 41% of the time.

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