Apollo Bay Swell Statistics, March: All Swell – Any Wind
The rose diagram shows the combination of swells directed at Apollo Bay over a normal March. It is based on 2220 NWW3 model predictions since 2007 (values every 3 hours). The wave model does not forecast surf and wind right at the shore so we have chosen the optimum grid node based on what we know about Apollo Bay, and at Apollo Bay the best grid node is 31 km away (19 miles).
The rose diagram illustrates the distribution of swell directions and swell sizes, while the graph at the bottom shows the same thing but without 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 2% of the time. Green and yellow illustrate increasing swell sizes and red represents the biggest swells, greater than >3m (>10ft). In both graphs, the area of any colour is proportional to how often that size swell happens.
The diagram indicates that the prevailing swell direction, shown by the longest spokes, was SW, whereas the the prevailing wind blows from the SSW. Because the wave model grid is away from the coast, sometimes a strong offshore wind blows largest waves away from Apollo Bay and out to sea. We group 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 Apollo Bay, you can load a different image that shows only the swells that were forecast to coincide with glassy or offshore wind conditions. During a typical March, swells large enough to cause clean enough to surf waves at Apollo Bay run for about 96% 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.