Statistiques de Houle pour Burreh Beach, Mai: Toutes Houles – Tous Vents
The rose diagram describes the range of swells directed at Burreh Beach through an average May. It is based on 2838 NWW3 model predictions since 2007 (values every 3 hours). The wave model does not forecast surf and wind right at the coast so we have chosen the best grid node based on what we know about Burreh Beach. In this particular case the best grid node is 29 km away (18 miles).
The rose diagram shows the distribution of swell sizes and swell direction, while the graph at the bottom shows the same thing but without direction information. Five colours illustrate increasing wave sizes. Blue shows the smallest swells, less that 0.5m (1.5 feet) high. These happened 30% of the time. Green and yellow represent increasing swell sizes and red represents the highest swells, greater than >3m (>10ft). In either graph, the area of any colour is proportional to how commonly that size swell occurs.
The diagram implies that the most common swell direction, shown by the biggest spokes, was SSW, whereas the the dominant wind blows from the WSW. Because the wave model grid is away from the coast, sometimes a strong offshore wind blows largest waves away from Burreh Beach and out to sea. We lump these in with the no surf category of the bar chart. To keep it simple we don't show these in the rose plot. Because wind determines whether or not waves are good for surfing at Burreh Beach, you can view an alternative image that shows only the swells that were expected to coincide with glassy or offshore wind conditions. In a typical May, swells large enough to cause clean enough to surf waves at Burreh Beach 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.