This chart illustrates the variation of swells directed at Shipwrecks Bay-Peaks over a normal September and is based upon 1680 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 Shipwrecks Bay-Peaks. In this particular case the best grid node is 23 km away (14 miles).

The rose diagram describes the distribution of swell sizes and directions, while the graph at the bottom shows the same thing but without direction information. Five colours represent increasing wave sizes. Very small swells of less than 0.5m (1.5 feet) high are shown in blue. These were forecast only 3% of the time. Green and yellow illustrate increasing swell sizes and red shows the largest swells, greater than >3m (>10ft). In either graph, the area of any colour is proportional to how frequently that size swell was forecast.

The diagram suggests that the prevailing swell direction, shown by the biggest spokes, was SW, whereas the the most common wind blows from the WSW. Because the wave model grid is out to sea, sometimes a strong offshore wind blows largest waves away from Shipwrecks Bay-Peaks and offshore. We combine 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 clean enough to surf at Shipwrecks Bay-Peaks, you can load a different image that shows only the swells that were forecast to coincide with glassy or offshore wind conditions. During a typical September, swells large enough to cause surfable waves at Shipwrecks Bay-Peaks run for about 73% 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.