This image shows the range of swells directed at Canggu through a typical southern hemisphere winter and is based upon 5066 NWW3 model predictions since 2006 (values every 3 hours). The wave model does not forecast surf and wind right at the shore so we have chosen the best grid node based on what we know about Canggu. In the case of Canggu, the best grid node is 40 km away (25 miles).
The rose diagram shows the distribution of swell sizes and swell direction, 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 0.8% of the time. Green and yellow represent 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 was forecast.
The diagram indicates that the most common swell direction, shown by the longest spokes, was SW, whereas the the prevailing wind blows from the ESE. Because the wave model grid is offshore, sometimes a strong offshore wind blows largest waves away from Canggu and away from the coast. We combine these with the no surf category of the bar chart. To keep it simple we don't show these in the rose graph. Because wind determines whether or not waves are good for surfing at Canggu, you can load a different image that shows only the swells that were expected to coincide with glassy or offshore wind conditions. Over an average southern hemisphere winter, swells large enough to cause clean enough to surf waves at Canggu run for about 99% 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.