Napier - Marine Parade Swell Statistics, September: All Swell – Any Wind
This chart describes the combination of swells directed at Napier - Marine Parade through a typical September. It is based on 1920 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 best grid node based on what we know about Napier - Marine Parade, and at Napier - Marine Parade the best grid node is 7 km away (4 miles).
The rose diagram illustrates the distribution of swell sizes and swell direction, 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 happened 77% of the time. Green and yellow illustrate increasing swell sizes and highest swells greater than >3m (>10ft) are shown in red. In each graph, the area of any colour is proportional to how frequently that size swell occurs.
The diagram suggests that the prevailing swell direction, shown by the longest spokes, was ENE, whereas the the dominant wind blows from the NW. Because the wave model grid is out to sea, sometimes a strong offshore wind blows largest waves away from Napier - Marine Parade and offshore. We combine these with the no surf category of the bar chart. To avoid confusion we don't show these in the rose graph. Because wind determines whether or not waves are surfable at Napier - Marine Parade, you can select a similar diagram that shows only the swells that were expected to coincide with glassy or offshore wind conditions. Over an average September, swells large enough to cause good for surfing waves at Napier - Marine Parade run for about 23% 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.