Koggala Lefts Surf Stats

The graph shows the variation of swells directed at Koggala Lefts through a typical April and is based upon 3360 NWW3 model predictions since 2007 (values every 3 hours). The wave model does not forecast wind and surf right at the shore so we have chosen the most applicable grid node based on what we know about Koggala Lefts. In this particular case the best grid node is 36 km away (22 miles). The rose diagram describes the distribution of swell sizes and directions, while the graph at the bottom shows the same thing but lacks 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 occurred only 4% of the time. Green and yellow illustrate increasing swell sizes and biggest swells greater than >3m (>10ft) are shown in red. In each graph, the area of any colour is proportional to how often that size swell happens. The diagram indicates that the most common swell direction, shown by the largest spokes, was SSW, 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 Koggala Lefts and offshore. We group these with the no surf category of the bar chart. To avoid confusion we don't show these in the rose plot. Because wind determines whether or not waves are clean enough to surf at Koggala Lefts, you can view an alternative image that shows only the swells that were forecast to coincide with glassy or offshore wind conditions. Over an average April, swells large enough to cause surfable waves at Koggala Lefts run for about 96% of the time.

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