Anawhata Road (Oaonui) Swell Statistics, December: All Swell – Any Wind
The rose diagram shows the variation of swells directed at Anawhata Road (Oaonui) over a normal December, based on 2457 NWW3 model predictions since 2006 (values every 3 hours). The wave model does not forecast surf and wind right at the coast so we have chosen the most applicable grid node based on what we know about Anawhata Road (Oaonui). In the case of Anawhata Road (Oaonui), the best grid node is 27 km away (17 miles).
The rose diagram describes the distribution of swell sizes and directions, 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 occurred only 17% of the time. Green and yellow illustrate increasing swell sizes and red represents biggest swells greater than >3m (>10ft). In both graphs, the area of any colour is proportional to how frequently that size swell occurs.
The diagram suggests that the most common swell direction, shown by the biggest spokes, was WSW, whereas the the prevailing wind blows from the WNW. Because the wave model grid is away from the coast, sometimes a strong offshore wind blows largest waves away from Anawhata Road (Oaonui) 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 Anawhata Road (Oaonui), you can select a similar diagram that shows only the swells that were forecast to coincide with glassy or offshore wind conditions. During a typical December, swells large enough to cause clean enough to surf waves at Anawhata Road (Oaonui) run for about 83% 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.