Freeport Channel Swell Statistics, April: All Swell – Any Wind
This image illustrates the variation of swells directed at Freeport Channel over a normal April. It is based on 2160 NWW3 model predictions since 2007 (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 Freeport Channel. In the case of Freeport Channel, the best grid node is 42 km away (26 miles).
The rose diagram illustrates the distribution of swell directions and swell sizes, while the graph at the bottom shows the same thing but without direction information. Five colours illustrate increasing wave sizes. Blue shows the smallest swells, less that 0.5m (1.5 feet) high. These happened only 42% of the time. Green and yellow illustrate increasing swell sizes and red represents the largest swells, greater than >3m (>10ft). In either graph, the area of any colour is proportional to how often that size swell occurs.
The diagram indicates that the prevailing swell direction, shown by the largest spokes, was ESE, whereas the the most common wind blows from the SE. Because the wave model grid is offshore, sometimes a strong offshore wind blows largest waves away from Freeport Channel and away from the coast. We combine these with the no surf category of the bar chart. To simplify things we don't show these in the rose graph. Because wind determines whether or not waves are good for surfing at Freeport Channel, you can select a similar diagram that shows only the swells that were predicted to coincide with glassy or offshore wind conditions. During a typical April, swells large enough to cause clean enough to surf waves at Freeport Channel run for about 0% 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.