In Betweens Swell Statistics, Winter: All Swell – Any Wind
This image shows the combination of swells directed at In Betweens through an average northern hemisphere winter, based on 5048 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 optimum grid node based on what we know about In Betweens, and at In Betweens the best grid node is 35 km away (22 miles).
The rose diagram illustrates the distribution of swell sizes and directions, 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 93% of the time. Green and yellow illustrate increasing swell sizes and biggest swells greater than >3m (>10ft) are shown in red. In either graph, the area of any colour is proportional to how frequently that size swell occurs.
The diagram suggests that the most common swell direction, shown by the longest spokes, was S, whereas the the prevailing wind blows from the E. Because the wave model grid is out to sea, sometimes a strong offshore wind blows largest waves away from In Betweens and offshore. We group these with the no surf category of the bar chart. To keep it simple we don't show these in the rose graph. Because wind determines whether or not waves are clean enough to surf at In Betweens, you can select a similar diagram that shows only the swells that were forecast to coincide with glassy or offshore wind conditions. In a typical northern hemisphere winter, swells large enough to cause surfable waves at In Betweens run for about 7% 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.