Anna Maria Key Swell Statistics, All Year: All Swell – Any Wind
This picture illustrates the variation of swells directed at Anna Maria Key over a normal year. It is based on 28003 NWW3 model predictions since 2006 (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 Anna Maria Key. In the case of Anna Maria Key, the best grid node is 26 km away (16 miles).
The rose diagram illustrates the distribution of swell directions and swell sizes, while the graph at the bottom shows the same thing but lacks direction information. Five colours illustrate increasing wave sizes. Blue shows the smallest swells, less that 0.5m (1.5 feet) high. These were forecast 80% of the time. Green and yellow show increasing swell sizes and red represents the largest swells, greater than >3m (>10ft). In either graph, the area of any colour is proportional to how frequently that size swell occurs.
The diagram suggests that the prevailing swell direction, shown by the largest spokes, was NW, whereas the the most common wind blows from the ENE. 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 group these with the no surf category of the bar chart. To avoid confusion we don't show these in the rose diagram. Because wind determines whether or not waves are surfable at Anna Maria Key, you can select a similar diagram that shows only the swells that were predicted to coincide with glassy or offshore wind conditions. During a typical year, swells large enough to cause good for surfing waves at Anna Maria Key run for about 20% 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.