Mouse Rock Swell Statistics, August: All Swell – Any Wind
This image illustrates the variation of swells directed at Mouse Rock through a typical August, based on 1984 NWW3 model predictions since 2006 (values every 3 hours). The wave model does not forecast surf and wind right at the coast so we have chosen the best grid node based on what we know about Mouse Rock, and at Mouse Rock the best grid node is 50 km away (31 miles).
The rose diagram describes 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 38% of the time. Green and yellow show increasing swell sizes and red illustrates the largest swells, greater than >3m (>10ft). In both graphs, the area of any colour is proportional to how often that size swell was forecast.
The diagram indicates that the most common swell direction, shown by the biggest spokes, was WNW (which was the same as the most common wind direction). Because the wave model grid is out to sea, sometimes a strong offshore wind blows largest waves away from Mouse Rock and offshore. We group 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 Mouse Rock, you can load a different image that shows only the swells that were forecast to coincide with glassy or offshore wind conditions. Over an average August, swells large enough to cause good for surfing waves at Mouse Rock run for about 62% 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.