Bird Island Surf Stats

The rose diagram illustrates the variation of swells directed at Bird Island through an average September and is based upon 3360 NWW3 model predictions since 2006 (values every 3 hours). The wave model does not forecast surf and wind right at the coastline so we have chosen the optimum grid node based on what we know about Bird Island. In this particular case the best grid node is 31 km away (19 miles). The rose diagram illustrates the distribution of swell sizes and swell direction, while the graph at the bottom shows the same thing but lacks direction information. Five colours illustrate increasing wave sizes. Blue shows the smallest swells, less that 0.5m (1.5 feet) high. These happened only 69% of the time. Green and yellow illustrate increasing swell sizes and red represents largest swells greater than >3m (>10ft). In both graphs, the area of any colour is proportional to how often that size swell occurs. The diagram indicates that the prevailing swell direction, shown by the longest spokes, was N, whereas the the most common wind blows from the ESE. Because the wave model grid is out to sea, sometimes a strong offshore wind blows largest waves away from Bird Island and offshore. We lump these in 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 clean enough to surf at Bird Island, you can load a different image that shows only the swells that were predicted to coincide with glassy or offshore wind conditions. In a typical September, swells large enough to cause surfable waves at Bird Island run for about 31% of the time.

read more