Avalanche Golf Statistieken, December: Alle Golven – Alle Wind
This image shows the range of swells directed at Avalanche through an average December. It is based on 2457 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 most applicable grid node based on what we know about Avalanche. In the case of Avalanche, the best grid node is 39 km away (24 miles).
The rose diagram describes the distribution of swell directions and swell sizes, while the graph at the bottom shows the same thing without direction information. Five colours illustrate increasing wave sizes. Blue shows the smallest swells, less that 0.5m (1.5 feet) high. These occurred only 3% of the time. Green and yellow illustrate increasing swell sizes and red represents the biggest 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 dominant swell direction, shown by the biggest spokes, was W, whereas the the prevailing wind blows from the S. Because the wave model grid is offshore, sometimes a strong offshore wind blows largest waves away from Avalanche and away from the coast. We combine these with the no surf category of the bar chart. To keep it simple we don't show these in the rose diagram. Because wind determines whether or not waves are good for surfing at Avalanche, you can load a different image that shows only the swells that were expected to coincide with glassy or offshore wind conditions. In a typical December, swells large enough to cause clean enough to surf waves at Avalanche run for about 97% 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.