In Betweens Swell Statistics, Winter: All Swell – Any Wind
The figure illustrates the combination of swells directed at In Betweens over a normal northern hemisphere winter and is based upon 6365 NWW3 model predictions since 2006 (values every 3 hours). The wave model does not forecast wind or surf right at the coastline so we have chosen the most applicable 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 shows the distribution of swell directions and swell sizes, while the graph at the bottom shows the same thing but 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 94% of the time. Green and yellow show increasing swell sizes and red shows 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 most common swell direction, shown by the biggest spokes, was S, whereas the the most common wind blows from the ENE. Because the wave model grid is away from the coast, sometimes a strong offshore wind blows largest waves away from In Betweens and out to sea. We combine 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 surfable at In Betweens, you can load a different image that shows only the swells that were predicted to coincide with glassy or offshore wind conditions. During a typical northern hemisphere winter, swells large enough to cause good for surfing waves at In Betweens run for about 6% 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.