This chart shows the combination of swells directed at Sanur Reef over a normal April and is based upon 1646 NWW3 model predictions since 2007 (values every 3 hours). The wave model does not forecast wind or surf right at the coast so we have chosen the optimum grid node based on what we know about Sanur Reef, and at Sanur Reef the best grid node is 44 km away (27 miles).
The rose diagram shows the distribution of swell sizes and directions, 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 occurred only 0% of the time. Green and yellow show increasing swell sizes and red shows the biggest swells, greater than >3m (>10ft). In each graph, the area of any colour is proportional to how frequently that size swell was forecast.
The diagram suggests that the dominant swell direction, shown by the longest spokes, was SSW, 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 Sanur Reef and away from the coast. We combine 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 surfable at Sanur Reef, you can select a similar diagram that shows only the swells that were forecast to coincide with glassy or offshore wind conditions. During a typical April, swells large enough to cause good for surfing waves at Sanur Reef run for about 22% 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.