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Surf Report Feed

Imperial Pier (North and South) Swell Statistics, September: All Swell – Any Wind

The graph illustrates the variation of swells directed at Imperial Pier (North and South) through an average September. It is based on 2880 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 best grid node based on what we know about Imperial Pier (North and South), and at Imperial Pier (North and South) the best grid node is 35 km away (22 miles).

The rose diagram illustrates the distribution of swell sizes and directions, while the graph at the bottom shows the same thing without direction information. Five colours show increasing wave sizes. The smallest swells, less than 0.5m (1.5 feet), high are coloured blue. These happened only 12% of the time. Green and yellow represent increasing swell sizes and red represents the largest swells, greater than >3m (>10ft). In either 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 SW, whereas the the most common 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 Imperial Pier (North and South) 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 plot. Because wind determines whether or not waves are surfable at Imperial Pier (North and South), you can load a different image that shows only the swells that were forecast to coincide with glassy or offshore wind conditions. In a typical September, swells large enough to cause good for surfing waves at Imperial Pier (North and South) run for about 88% 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.