The rose diagram describes the range of swells directed at Pauanui Beach over a normal January and is based upon 1728 NWW3 model predictions since 2007 (values every 3 hours). The wave model does not forecast wind and surf right at the coast so we have chosen the optimum grid node based on what we know about Pauanui Beach. In the case of Pauanui Beach, the best grid node is 12 km away (7 miles).
The rose diagram shows the distribution of swell sizes and swell direction, while the graph at the bottom shows the same thing but 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 10% of the time. Green and yellow show 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 prevailing swell direction, shown by the largest spokes, was ENE, 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 Pauanui Beach 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 diagram. Because wind determines whether or not waves are surfable at Pauanui Beach, you can view an alternative image that shows only the swells that were forecast to coincide with glassy or offshore wind conditions. During a typical January, swells large enough to cause good for surfing waves at Pauanui Beach run for about 34% 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.