Coos Bay-South Jetty Surf Stats

The figure illustrates the range of swells directed at Coos Bay-South Jetty through a typical October. It is based on 3471 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 most applicable grid node based on what we know about Coos Bay-South Jetty, and at Coos Bay-South Jetty the best grid node is 21 km away (13 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 illustrate increasing wave sizes. Blue shows the smallest swells, less that 0.5m (1.5 feet) high. These were forecast only 1.5% of the time. Green and yellow represent increasing swell sizes and red represents the largest swells, greater than >3m (>10ft). In both graphs, the area of any colour is proportional to how frequently that size swell was forecast. The diagram suggests that the dominant swell direction, shown by the longest spokes, was W, whereas the the most common wind blows from the N. Because the wave model grid is out to sea, sometimes a strong offshore wind blows largest waves away from Coos Bay-South Jetty 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 Coos Bay-South Jetty, you can select a similar diagram that shows only the swells that were forecast to coincide with glassy or offshore wind conditions. Over an average October, swells large enough to cause good for surfing waves at Coos Bay-South Jetty run for about 98% of the time.

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