The Pass Swell Statistics, Novembre: All Swell – Any Wind
This picture illustrates the variation of swells directed at The Pass over a normal November, based on 2377 NWW3 model predictions since 2006 (values every 3 hours). The wave model does not forecast wind and surf right at the shore so we have chosen the optimum grid node based on what we know about The Pass. In the case of The Pass, the best grid node is 29 km away (18 miles).
The rose diagram shows 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 69% of the time. Green and yellow show increasing swell sizes and red represents largest swells greater than >3m (>10ft). In either graph, the area of any colour is proportional to how commonly that size swell happens.
The diagram implies that the prevailing swell direction, shown by the biggest spokes, was ESE, whereas the the most common wind blows from the NE. Because the wave model grid is out to sea, sometimes a strong offshore wind blows largest waves away from The Pass and offshore. We combine 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 load a different image that shows only the swells that were forecast to coincide with glassy or offshore wind conditions. During a typical November, swells large enough to cause surfable waves at The Pass run for about 5% 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.