Noosa - Alexandria Bay Swell Statistics, December: All Swell – Any Wind
This image describes the variation of swells directed at Noosa - Alexandria Bay through an average December, based on 2457 NWW3 model predictions since 2006 (values every 3 hours). The wave model does not forecast wind and surf right at the coastline so we have chosen the most applicable grid node based on what we know about Noosa - Alexandria Bay. In the case of Noosa - Alexandria Bay, the best grid node is 40 km away (25 miles).
The rose diagram illustrates 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 75% of the time. Green and yellow represent increasing swell sizes and red represents highest 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 most common swell direction, shown by the longest spokes, was SSE, whereas the the dominant wind blows from the ENE. Because the wave model grid is offshore, sometimes a strong offshore wind blows largest waves away from Noosa - Alexandria Bay 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 Noosa - Alexandria Bay, you can load a different image that shows only the swells that were predicted to coincide with glassy or offshore wind conditions. In a typical December, swells large enough to cause good for surfing waves at Noosa - Alexandria Bay run for about 25% 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.