Anna Bay-Morna Point Swell Statistics, Winter: All Swell – Any Wind
The graph describes the variation of swells directed at Anna Bay-Morna Point through an average southern hemisphere winter and is based upon 7266 NWW3 model predictions since 2006 (values every 3 hours). The wave model does not forecast wind or surf right at the coast so we have chosen the best grid node based on what we know about Anna Bay-Morna Point, and at Anna Bay-Morna Point the best grid node is 25 km away (16 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 happened only 37% of the time. Green and yellow represent increasing swell sizes and red represents highest 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 prevailing swell direction, shown by the largest spokes, was ESE, whereas the the dominant wind blows from the W. Because the wave model grid is offshore, sometimes a strong offshore wind blows largest waves away from Anna Bay-Morna Point 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 Anna Bay-Morna Point, you can select a similar diagram that shows only the swells that were forecast to coincide with glassy or offshore wind conditions. In a typical southern hemisphere winter, swells large enough to cause clean enough to surf waves at Anna Bay-Morna Point run for about 41% 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.