The Pass Swell Statistics, Luglio: All Swell – Any Wind
The figure illustrates the range of swells directed at The Pass over a normal July and is based upon 2475 NWW3 model predictions since 2006 (values every 3 hours). The wave model does not forecast surf and wind right at the shore so we have chosen the most applicable grid node based on what we know about The Pass. In this particular case the best grid node is 29 km away (18 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 represent increasing wave sizes. Very small swells of less than 0.5m (1.5 feet) high are shown in blue. These occurred 88% of the time. Green and yellow illustrate increasing swell sizes and red shows the largest swells, greater than >3m (>10ft). In either graph, the area of any colour is proportional to how frequently that size swell occurs.
The diagram suggests that the dominant swell direction, shown by the biggest spokes, was SE, whereas the the most common wind blows from the SW. Because the wave model grid is offshore, sometimes a strong offshore wind blows largest waves away from The Pass and away from the coast. We group these with the no surf category of the bar chart. To simplify things we don't show these in the rose diagram. Because wind determines whether or not waves are clean enough to surf at The Pass, you can select a similar diagram that shows only the swells that were forecast to coincide with glassy or offshore wind conditions. During a typical July, swells large enough to cause surfable waves at The Pass run for about 1.0% 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.