Awatoto Rivermouth Swell Statistics, March: All Swell – Any Wind
The rose diagram describes the combination of swells directed at Awatoto Rivermouth through a typical 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 coast so we have chosen the optimum grid node based on what we know about Awatoto Rivermouth. In this particular case the best grid node is 7 km away (4 miles).
The rose diagram shows 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 were forecast only 33% of the time. Green and yellow show increasing swell sizes and red represents the highest swells, greater than >3m (>10ft). In each graph, the area of any colour is proportional to how often that size swell occurs.
The diagram indicates that the most common swell direction, shown by the longest spokes, was ESE, whereas the the dominant wind blows from the NNW. Because the wave model grid is out to sea, sometimes a strong offshore wind blows largest waves away from Awatoto Rivermouth and offshore. We combine these with the no surf category of the bar chart. To keep it simple we don't show these in the rose diagram. Because wind determines whether or not waves are good for surfing at Awatoto Rivermouth, you can view an alternative image that shows only the swells that were expected to coincide with glassy or offshore wind conditions. Over an average March, swells large enough to cause clean enough to surf waves at Awatoto Rivermouth run for about 67% 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.