Merewether - Ladies Swell Statistics, September: All Swell – Any Wind
The graph describes the combination of swells directed at Merewether - Ladies over a normal September and is based upon 2400 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 Merewether - Ladies. In this particular case the best grid node is 22 km away (14 miles).
The rose diagram shows the distribution of swell directions and swell sizes, while the graph at the bottom shows the same thing without direction information. Five colours illustrate increasing wave sizes. Blue shows the smallest swells, less that 0.5m (1.5 feet) high. These were forecast only 36% of the time. Green and yellow illustrate increasing swell sizes and highest swells greater than >3m (>10ft) are shown in red. In either graph, the area of any colour is proportional to how often that size swell happens.
The diagram indicates that the dominant swell direction, shown by the longest spokes, was ESE, whereas the the dominant wind blows from the NW. Because the wave model grid is offshore, sometimes a strong offshore wind blows largest waves away from Merewether - Ladies and away from the coast. 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 plot. Because wind determines whether or not waves are clean enough to surf at Merewether - Ladies, you can load a different image that shows only the swells that were predicted to coincide with glassy or offshore wind conditions. During a typical September, swells large enough to cause surfable waves at Merewether - Ladies run for about 64% 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.