Statistiques de Houle pour Avalon Pier, Mars: Toutes Houles – Tous Vents
This chart illustrates the combination of swells directed at Avalon Pier through an average March, based on 2220 NWW3 model predictions since 2007 (values every 3 hours). The wave model does not forecast wind or surf right at the shore so we have chosen the most applicable grid node based on what we know about Avalon Pier, and at Avalon Pier the best grid node is 17 km away (11 miles).
The rose diagram illustrates the distribution of swell directions and swell sizes, 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 30% of the time. Green and yellow show increasing swell sizes and red shows largest swells greater than >3m (>10ft). In both graphs, the area of any colour is proportional to how commonly that size swell was forecast.
The diagram implies that the dominant swell direction, shown by the biggest spokes, was NE, whereas the the most common wind blows from the NW. Because the wave model grid is out to sea, sometimes a strong offshore wind blows largest waves away from Avalon Pier and offshore. We group these with the no surf category of the bar chart. To avoid confusion we don't show these in the rose graph. Because wind determines whether or not waves are clean enough to surf at Avalon Pier, you can select a similar diagram that shows only the swells that were predicted to coincide with glassy or offshore wind conditions. In a typical March, swells large enough to cause surfable waves at Avalon Pier run for about 70% 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.