Statistiques de Houle pour Ardnave Point and Bay (Islay), Mars: Toutes Houles – Tous Vents
The rose diagram describes the variation of swells directed at Ardnave Point and Bay (Islay) over a normal March and is based upon 2220 NWW3 model predictions since 2007 (values every 3 hours). The wave model does not forecast surf and wind right at the shore so we have chosen the best grid node based on what we know about Ardnave Point and Bay (Islay). In this particular case the best grid node is 18 km away (11 miles).
The rose diagram describes the distribution of swell directions and swell sizes, 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 only 12% of the time. Green and yellow illustrate increasing swell sizes and red represents highest swells greater than >3m (>10ft). In both graphs, 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 longest spokes, was WNW, whereas the the dominant wind blows from the SW. Because the wave model grid is out to sea, sometimes a strong offshore wind blows largest waves away from Ardnave Point and Bay (Islay) 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 graph. Because wind determines whether or not waves are surfable at Ardnave Point and Bay (Islay), you can load a different image that shows only the swells that were predicted to coincide with glassy or offshore wind conditions. During a typical March, swells large enough to cause good for surfing waves at Ardnave Point and Bay (Islay) run for about 53% 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.