Andromeda Swell Statistics, November: All Swell – Any Wind
The graph describes the variation of swells directed at Andromeda over a normal November. It is based on 2387 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 optimum grid node based on what we know about Andromeda, and at Andromeda the best grid node is 63 km away (39 miles).
The rose diagram illustrates the distribution of swell sizes and directions, while the graph at the bottom shows the same thing 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 show increasing swell sizes and red represents highest swells greater than >3m (>10ft). In each graph, the area of any colour is proportional to how commonly that size swell was forecast.
The diagram implies that the most common swell direction, shown by the longest spokes, was SW, whereas the the dominant wind blows from the SSW. Because the wave model grid is out to sea, sometimes a strong offshore wind blows largest waves away from Andromeda and offshore. We lump these in 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 surfable at Andromeda, you can select a similar diagram that shows only the swells that were predicted to coincide with glassy or offshore wind conditions. During a typical November, swells large enough to cause good for surfing waves at Andromeda run for about 98% 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.