Anna Maria Key Swell Statistics, January: All Swell – Any Wind
The figure describes the variation of swells directed at Anna Maria Key through a typical January and is based upon 2370 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 optimum grid node based on what we know about Anna Maria Key. In this particular case the best grid node is 26 km away (16 miles).
The rose diagram illustrates the distribution of swell sizes and swell direction, 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 happened 63% of the time. Green and yellow illustrate increasing swell sizes and highest swells greater than >3m (>10ft) are shown in red. In both graphs, the area of any colour is proportional to how often that size swell occurs.
The diagram indicates that the most common swell direction, shown by the biggest spokes, was NW, whereas the the dominant wind blows from the NE. Because the wave model grid is offshore, sometimes a strong offshore wind blows largest waves away from Anna Maria Key and away from the coast. 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 graph. Because wind determines whether or not waves are good for surfing at Anna Maria Key, you can view an alternative image that shows only the swells that were expected to coincide with glassy or offshore wind conditions. Over an average January, swells large enough to cause clean enough to surf waves at Anna Maria Key run for about 37% 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.