This chart illustrates the variation of swells directed at Mouse Rock over a normal January. It is based on 1728 NWW3 model predictions since 2007 (values every 3 hours). The wave model does not forecast surf and wind right at the shore so we have chosen the best grid node based on what we know about Mouse Rock. In the case of Mouse Rock, the best grid node is 50 km away (31 miles).
The rose diagram shows the distribution of swell sizes and swell direction, while the graph at the bottom shows the same thing but lacks 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 2% 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 frequently that size swell happens.
The diagram suggests that the prevailing swell direction, shown by the biggest spokes, was WNW, whereas the the most common wind blows from the N. Because the wave model grid is offshore, sometimes a strong offshore wind blows largest waves away from Mouse Rock and away from the coast. We group these with the no surf category of the bar chart. To keep it simple we don't show these in the rose diagram. Because wind determines whether or not waves are surfable at Mouse Rock, you can view an alternative image that shows only the swells that were expected to coincide with glassy or offshore wind conditions. During a typical January, swells large enough to cause good for surfing waves at Mouse Rock run for about 98% 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.