Atlantida Swell Statistics, March: All Swell – Any Wind
The rose diagram shows the variation of swells directed at Atlantida over a normal March. It is based on 2220 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 optimum grid node based on what we know about Atlantida. In the case of Atlantida, the best grid node is 22 km away (14 miles).
The rose diagram illustrates the distribution of swell sizes and directions, 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 27% of the time. Green and yellow show increasing swell sizes and red represents the biggest swells, greater than >3m (>10ft). In each graph, the area of any colour is proportional to how commonly that size swell occurs.
The diagram implies that the prevailing swell direction, shown by the longest spokes, was SE, whereas the the prevailing wind blows from the ENE. Because the wave model grid is away from the coast, sometimes a strong offshore wind blows largest waves away from Atlantida and out to sea. We group 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 clean enough to surf at Atlantida, you can load a different image that shows only the swells that were expected to coincide with glassy or offshore wind conditions. During a typical March, swells large enough to cause surfable waves at Atlantida run for about 73% 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.