The Strait Swell Statistics, December: All Swell – Any Wind
This chart describes the range of swells directed at The Strait through a typical December. It is based on 2209 NWW3 model predictions since 2006 (values every 3 hours). The wave model does not forecast wind and surf right at the coastline so we have chosen the best grid node based on what we know about The Strait, and at The Strait the best grid node is 44 km away (27 miles).
The rose diagram shows the distribution of swell sizes and swell direction, 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 were forecast only 23% of the time. Green and yellow illustrate increasing swell sizes and highest 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 was forecast.
The diagram suggests that the dominant swell direction, shown by the longest spokes, was W, whereas the the dominant wind blows from the SE. Because the wave model grid is away from the coast, sometimes a strong offshore wind blows largest waves away from The Strait and out to sea. We group these with the no surf category of the bar chart. To avoid confusion we don't show these in the rose diagram. Because wind determines whether or not waves are surfable at The Strait, you can select a similar diagram that shows only the swells that were forecast to coincide with glassy or offshore wind conditions. Over an average December, swells large enough to cause good for surfing waves at The Strait run for about 57% 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.