The Pass Swell Statistics, Ottobre: All Swell – Any Wind
This image shows the variation of swells directed at The Pass through a typical October, based on 2477 NWW3 model predictions since 2006 (values every 3 hours). The wave model does not forecast wind or surf right at the coast so we have chosen the best 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 describes the distribution of swell sizes and directions, 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 occurred 76% of the time. Green and yellow show increasing swell sizes and red illustrates the biggest swells, greater than >3m (>10ft). In each graph, the area of any colour is proportional to how frequently that size swell was forecast.
The diagram suggests that the most common swell direction, shown by the biggest spokes, was ESE, whereas the the prevailing wind blows from the NE. Because the wave model grid is away from the coast, sometimes a strong offshore wind blows largest waves away from The Pass and out to sea. We lump these in with the no surf category of the bar chart. To avoid confusion we don't show these in the rose plot. Because wind determines whether or not waves are good for surfing at The Pass, you can load a different image that shows only the swells that were expected to coincide with glassy or offshore wind conditions. Over an average October, swells large enough to cause clean enough to surf waves at The Pass run for about 3% 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.