This chart illustrates the range of swells directed at Northern Rights over a normal August. It is based on 1736 NWW3 model predictions since 2006 (values every 3 hours). The wave model does not forecast wind or surf right at the coast so we have chosen the best grid node based on what we know about Northern Rights, and at Northern Rights the best grid node is 46 km away (29 miles).
The rose diagram shows the distribution of swell directions and swell sizes, while the graph at the bottom shows the same thing 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 occurred only 0% of the time. Green and yellow illustrate increasing swell sizes and red represents the largest swells, greater than >3m (>10ft). In each graph, the area of any colour is proportional to how commonly that size swell occurs.
The diagram implies that the dominant swell direction, shown by the biggest spokes, was SW, whereas the the most common wind blows from the SE. Because the wave model grid is out to sea, sometimes a strong offshore wind blows largest waves away from Northern Rights and offshore. We lump these in with the no surf category of the bar chart. To simplify things we don't show these in the rose graph. Because wind determines whether or not waves are surfable at Northern Rights, you can select a similar diagram that shows only the swells that were expected to coincide with glassy or offshore wind conditions. During a typical August, swells large enough to cause good for surfing waves at Northern Rights run for about 99% 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.