Statistiques de Houle pour Anna Maria Key, Mars: Toutes Houles – Tous Vents
This picture describes the range of swells directed at Anna Maria Key through an average March and is based upon 2217 NWW3 model predictions since 2007 (values every 3 hours). The wave model does not forecast wind or surf right at the coast so we have chosen the most applicable 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 shows the distribution of swell directions and swell sizes, while the graph at the bottom shows the same thing but lacks direction information. Five colours represent increasing wave sizes. Very small swells of less than 0.5m (1.5 feet) high are shown in blue. These happened 74% of the time. Green and yellow illustrate increasing swell sizes and red illustrates highest 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 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 group these with the no surf category of the bar chart. To simplify things we don't show these in the rose diagram. Because wind determines whether or not waves are surfable 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. In a typical March, swells large enough to cause good for surfing waves at Anna Maria Key run for about 26% 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.