Airport Lefts Swell Statistics, Summer: All Swell – Any Wind
This picture illustrates the range of swells directed at Airport Lefts through an average southern hemisphere summer and is based upon 6931 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 most applicable grid node based on what we know about Airport Lefts. In this particular case the best grid node is 33 km away (21 miles).
The rose diagram illustrates the distribution of swell sizes and swell direction, while the graph at the bottom shows the same thing without direction information. Five colours illustrate increasing wave sizes. Blue shows the smallest swells, less that 0.5m (1.5 feet) high. These were forecast only 0% of the time. Green and yellow represent increasing swell sizes and red illustrates largest swells greater than >3m (>10ft). In either graph, the area of any colour is proportional to how frequently that size swell occurs.
The diagram suggests that the most common swell direction, shown by the largest spokes, was SW, whereas the the most common wind blows from the W. Because the wave model grid is out to sea, sometimes a strong offshore wind blows largest waves away from Airport Lefts and offshore. We group these 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 good for surfing at Airport Lefts, 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 southern hemisphere summer, swells large enough to cause clean enough to surf waves at Airport Lefts run for about 100% 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.